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Novel fuzzy logic controllers with self-tuning capability
No full textTwo controllers which extend the PD+I fuzzy logic controller to deal with the plant having time varying nonlinear dynamics are proposed. The adaptation ability of the first self tuning PD+I fuzzy logic controller (STPD+I_31) is achieved by adjusting the output scaling factor automatically thereby contributing to significant improvement in performance. Second controller (STPD+I_9) is the simplified version of STPD+I_31 which is designed under the imposed constraint that allows only minimum number of rules in the rule bases. The proposed controllers are compared with two classical nonlinear controllers: the pole placement self tuning PID controller and sliding mode controller. All the controllers are applied to the two-links revolute robot for the tracking control. The tracking performance of STPD+I_31 and STPD+I_9 are much better than the pole placement self tuning PID controller during high speed motions while the performance are comparable at low and medium speed. In addition, STPD+I_31 and STPD+I_9 outperform sliding mode controller using same method of comparison study
Letter from A. F. Potter to John H. Page
No full textLetter from A. F. Potter to John H. Page referring his request to build a railway to the District Forester at Albuquerque, New Mexico
Polly H. Carder Collection on George F. Root
No full textGeorge Frederick Root (1820-1895) was an American songwriter and music educator. He is perhaps best known for his song "The Battle Cry of Freedom," which was written and rose to popularity during the U.S. Civil War. The Polly H. Carder Collection on George F. Root contains original published scores and songbooks from the period 1852-1907 and photocopied scores collected by Polly H. Carder, author of the book George F. Root, Civil War Songwriter: A Biography. The collection also contains a short article, "The Last Days of George F. Root," written by Root's daughter, Clara Louise Burnham
Experimental determination of the contact pressures produced by a nasal continuous positive airway pressure mask: A case study
No full textBackground: A continuous positive airway pressure (CPAP) mask is a respiratory ventilation method used for treating breathing disorders including respiratory failure and obstructive sleep apnoea (OSA). The forces applied by a CPAP mask may affect facial development and lead to pressure ulcers. In an experimental setting, the magnitude and the distribution of the contact pressures developed by a CPAP mask on the face were investigated for providing information aiming at optimizing the design of the device. Materials and methods: A nasal CPAP mask with forehead support was placed via its headgear straps on a rigid phantom head and then a controlled load was incrementally applied via a mechanical testing system (5848 Micro Tester, Instron), up to 4 maximum levels of exerted force, namely 5 N, 10 N, 15 N, and 20 N. Real-time pressure mapping was realized by means of sensor matrixes (I-Scan System, Tekscan) applied on the facial surface in four regions (forehead, nasal bridge, zygoma, and maxilla). The data were then transferred on a virtual model created by 3D scans of both the CPAP mask and the phantom head used in the experiments. Results: At increasing applied force, increases in average contact pressure were present at the zygomatic region (1–8 kPa), nasal bridge (12–14 kPa), and forehead (13–29 kPa), while the maxillary region showed relatively stable values (9 kPa). Despite the overall increase in average contact pressure with increasing applied force, no direct proportionality was present. Contact areas did not show clear increments, despite force may redistribute on a larger area, as sensors did not cover the entire mask perimeter. Peak contact pressure values were somehow affected by pressure concentrations that led to saturation in some areas of the sensors (up to 2% of the sensels). Conclusions: The CPAP mask exerts pressures that may be not uniformly distributed on the face of a subject. This information underlines the clinical importance of assessing both the pressure exerted and the areas that are interested by the mask contact, so as to optimise the CPAP masks design for obtaining a good compromise between ventilation performance and reduction of possible side effects on living tissues
Sutural Morphology in the Craniofacial Skeleton: A Descriptive Microcomputed Tomography Study in a Swine Model
No full textSutures are greatly involved in both normal craniofacial growth and developmental anomalies. Having clear parameters for defining their morphology is fundamental to properly investigate their physiological or pathological development. However, the current literature is lacking of well-defined methods for the assessment of these structures. This study performed a comprehensive microcomputed tomography (μCT) analysis of a swine model evaluating morphological variation of sutures in different skull regions. Seventy-two suture samples were removed from one swine (Sus scrofa), approximately 9–12-month-old. Each sample was analyzed with μCT in the parallel (PAR) and perpendicular (PER) plane with respect to the bone surface. Suture width (Sw), linear obliteration index (LOI), and linear interdigitation index (LII) were calculated in each of the two reference planes, and sutures were categorized in four types (St). Parameters were compared among the facial, craniofacial, and cranial region. Description of the main morphological parameters was provided, and differences were found between the parallel and perpendicular planes. St varied depending on the skull region, with simple sutures more represented in the cranial region. LII in the perpendicular plane decreased from facial to craniofacial and cranial region. Sw in the parallel plane decreased from facial and craniofacial to cranial region. In the swine model, the sutural width, linear interdigitation, and suture type were related to distinct skull regions. The suture type was introduced to allow a better morphological characterization of sutures as 3D structures. Clear definition of sutural parameters is important for appropriate description of these complex structures. Anat Rec, 302:2156–2163, 2019. © 2019 American Association for Anatomy
Evaluation of rapid maxillary expansion through acoustic emission technique and relative soft tissue attenuation
No full textObjectives:
Acoustic emission (AE) is a non-destructive test to detect energy release. This technique was applied during rapid maxillary expansion (RME) to evaluate the reaction of the craniofacial skeleton.
Materials and methods:
A swine model was analysed. Soft tissues were removed from two heads, while other two were preserved intact. A palatal expander (PE) was positioned and AE sensors were placed on the intermaxillary, fronto-nasal, and maxillo-lacrimal sutures. The PE was activated and AE recorded during RME. Differences between parameters were analysed with Mann-Whitney U test and Kruskal-Wallis test, and correlations with Spearman-Rho test (significance p<0.05).
Results:
PE activations were accompanied by clusters of AE hits. In the presence of soft tissues, amplitudes were generally lower (p<0.001) and durations were higher (p<0.001). No differences were found in the respective energy values. Differences were found in the AE (p<0.05) among the four channels, with AE characterised by higher values in proximity of the maxillo-lacrimal sutures. High-energy hits were represented by burst-type waves, and low-energy ones by continuous-type.
Conclusions:
Although soft tissues create possible attenuation of the signal, AE can be detected during RME with sensors on the skin. AE provided further information of energy release, on top of the mechanical parameters. Source location was one of the main limitations.link_to_subscribed_fulltex
Electron and positron scattering from 1,1-C₂H₂F₂
No full text1,1-difluoroethylene (1,1-C₂H₂F₂) molecules have been studied for the first time experimentally and theoretically by electron and positron impact. 0.4-1000 eV electron and 0.2-1000 eV positron impact total cross sections (TCSs) were measured using a retarding potential time-of-flight apparatus. In order to probe the resonances observed in the electron TCSs, a crossed-beam method was used to investigate vibrational excitation cross sections over the energy range of 1.3-49 eV and scattering angles 90 degrees and 120 degrees for the two loss energies 0.115 and 0.381 eV corresponding to the dominant C-H (ν₂ and ν₉) stretching and the combined C-F (ν₃) stretching and CH₂ (ν₁₁) rocking vibrations, respectively. Electron impact elastic integral cross sections are also reported for calculations carried out using the Schwinger multichannel method with pseudopotentials for the energy range from 0.5 to 50 eV in the static-exchange approximation and from 0.5 to 20 eV in the static-exchange plus polarization approximation. Resonance peaks observed centered at about 2.3, 6.5, and 16 eV in the TCSs have been shown to be mainly due to the vibrational and elastic channels, and assigned to the B₂, B₁, and A₁ symmetries, respectively. The pi* resonance peak at 1.8 eV in C₂H₄ is observed shifted to 2.3 eV in 1,1-C₂H₂F₂ and to 2.5 eV in C₂F₄; a phenomenon attributed to the decreasing C=C bond length from C₂H₄ to C₂F₄. For positron impact a conspicuous peak is observed below the positronium formation threshold at about 1 eV, and other less pronounced ones centered at about 5 and 20 eV.The work was supported in part by a Grant-in-Aid, the
Ministry of Education, Science, Technology, Sport and Culture,
Japan, the Japan Society for the Promotion of Science
JSPS, and the Japan Atomic Energy Research Institute
JAERI. One of the authors C.M. is also grateful to the
JSPS for financial support under Grant No. P04064. Another
author H.T. acknowledges Dr. T. Ozeki of the JAERI for
his encouragement and support during this work. This work
was also done under the International Atomic Energy Agency
IAEA project for three of the authors C.M., M.H., and
H.T.. Two of the authors M.H.F.B. and M.A.P.L. acknowledge
support from the Brazilian agency Conselho Nacional
de Desenvolvimento Científico e Tecnológico CNPq.
MHFB also acknowledges support from the Paraná state
agency Fundação Araucária and from FINEP ( under Project
No. CT-Infra 1)
Anatomical and mechanical properties of swine midpalatal suture in the premaxillary, maxillary, and palatine region
No full textThe mechanical properties of the midpalatal suture and their relationship with anatomical parameters are relevant for both tissue engineering and clinical treatments, such as in sutural distraction osteogenesis. Soft tissues were dissected from ten swine heads and the hard palate was sliced perpendicularly to the midpalatal suture. Thirteen specimens were collected from each animal and analysed with micro-computed tomography and 4-point-bending for sutural width (Sw), interdigitation (LII), obliteration (LOI), failure stress (σ f ), elastic modulus (E), and bone mineral density (BMD). Values of the premaxillary, maxillary, and palatine region were compared with Kruskal-Wallis one-way ANOVA and Spearman's rank coefficient was used to analyse the correlation between parameters and their position along the suture (α = 0.05). LII had values of 1.0, 2.9, and 4.3, LOI had values of 0.0%, 2.5%, and 4.5%, and E had values of 12.5 MPa, 31.3 MPa, and 98.5 MPa, in the premaxillary, maxillary, and palatine region, respectively (p < 0.05). Failure stress and rigidity of the midpalatal suture increased from rostral to caudal, due to greater interdigitation and obliteration. These anatomical and mechanical findings contribute to characterise maxillary growth, and may help to understand its mechanical reaction during loading, and in virtual simulations
„f“ AND „h“ LETTERS\u27 PROBLEM IN LATGALIAN LANGUAGE
No full textIn the article is told about the problem of letters’ (and sounds’) f and h in Latgalian language. These sounds have never been in any Latgalian dialect, in foreign words speakers always have been replaced them with other sounds. At the same time letters f and h have been used in written Latgalian at all times: from the first known book „Evangelia toto anno“ to the present day. What to do in this situation: to keep the way of the still alive traditional spoken language, or to yield to the pressure of other languages?The author analyzes a variety of sources: tells about reconstructions of source languages and opinions of their researchers about presence/absence of these sounds in them, deals with f in contemporary Eurasian languages (Eastern Slavic: Russian, Ukrainian, Belarusian; Finnic: Finnish, Estonian, Vyru; Turkic: Kyrgyz, Kazakh, Chuvash, Yakut; Persian: Pashto; Baltic: Lithuanian, Samogitian) and h in contemporary Eurasian languages (French, Kazakh, Lithuanian, Samogitian). Latgalian and Latvian dialects’ recordings, folk songs, ancient texts (from XVI–XVIII centuries), as well as Latgalian contemporary literature are analyzed. The author also evaluates inclusion of letters f and h in alphabet of the official Latgalian terms of spelling in year 2007.Author establishes that there are five possible paths:1) to use the f and h in all the words where they are in Latvian, Russian or other languages;2) to keep p, k, g and c in traditionally used words, but to put f and h in newly borrowed ones;3) do not use the f and h at all;4) to use both variants parallely in the same words;5) to write f and h, but to pronounce them as p and k.Author concludes that the actualy usable are only two of them: the second one – the way of a compromise, and the third one – as the most appropriate to Latgalian phonological system
A 2 h periodic variation in the low-mass X-ray binary Ser X-1
No full textSpectroscopy of the low-mass X-ray binary Ser X-1 using the Gran Telescopio Canarias have revealed a ?2 h periodic variability that is present in the three strongest emission lines. We tentatively interpret this variability as due to orbital motion, making it the first indication of the orbital period of Ser X-1. Together with the fact that the emission lines are remarkably narrow, but still resolved, we show that a main-sequence K dwarf together with a canonical 1.4 M? neutron star gives a good description of the system. In this scenario, the most likely place for the emission lines to arise is the accretion disc, instead of a localized region in the binary (such as the irradiated surface or the stream-impact point), and their narrowness is due instead to the low inclination (?10°) of Ser X-1
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