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Nonlinear Mathematical Modeling in Pneumatic Servo Position Applications
Antonio Carlos Valdiero,Carla Silvane Ritter,Cláudio Fernando Rios,Marat Rafikov
Mathematical Problems in Engineering , 2011, DOI: 10.1155/2011/472903
Abstract: This paper addresses a new methodology for servo pneumatic actuators mathematical modeling and selection from the dynamic behavior study in engineering applications. The pneumatic actuator is very common in industrial application because it has the following advantages: its maintenance is easy and simple, with relatively low cost, self-cooling properties, good power density (power/dimension rate), fast acting with high accelerations, and installation flexibility. The proposed fifth-order nonlinear mathematical model represents the main characteristics of this nonlinear dynamic system, as servo valve dead zone, air flow-pressure relationship through valve orifice, air compressibility, and friction effects between contact surfaces in actuator seals. Simulation results show the dynamic performance for different pneumatic cylinders in order to see which features contribute to a better behavior of the system. The knowledge of this behavior allows an appropriate choice of pneumatic actuator, mainly contributing to the success of their precise control in several applications.
A Pure Mathematical Relationship between Pitch and Position for Stringed Instruments  [PDF]
Nan Yang, Dawei Zhang, Yanling Tian
Applied Mathematics (AM) , 2014, DOI: 10.4236/am.2014.510143
Abstract:

In this paper, a simple mathematical model was proposed to answer such a question: what’s the relationship between the finger pressing position and the corresponding pitch for stringed instruments? Furthermore, we compared the theoretical results with measurement results which were obtained from a guitar to prove that the model we propose is reliable. Result shows that relative errors of theoretical results and measurement results are from 0.18% to 1.8%. The mathematics model is more concise, direct and clear than physical model.

Mathematical Model of the Criterion of Optimization by Compensation for Designing Commercial Bottles with Lateral Surfaces of Revolution and a Straight Section along Its Silhouette  [PDF]
Lizandro B. R. Zegarra, Luis E. G. Armas, Aida D. Reyna, Julio A. L. Vergara, Fidel A. V. Obeso
Open Journal of Optimization (OJOp) , 2017, DOI: 10.4236/ojop.2017.63009
Abstract: In this article, the mathematical foundations of the so called Criterion of Optimization by Compensation for designing commercial bottles with a straight section along its silhouette and with lateral surfaces of revolution is presented. Such mathematical model uses as main tools, Lagrange polynomial interpolation and Newton’s Method for Nonlinear Systems being first necessary to formulate and demonstrate a theorem. It was redesigned and manufactured a bottle of a half-liter of Fanta soda of the well-known Coca Cola Company, which uses 18.86% more material that such criterion establishes. It was expected that the redesigned bottle use 4.91% more of material with respect to what is established by the Criterion of Optimization by Compensation. However, it was reported a 13% of mistake due to important limitations that must be overcome.
Mathematical modelling and study of the encoding readout scheme for position sensitive detectors  [PDF]
Xiaoguang Yue,Ming Zeng,Zhi Zeng,Yi Wang,Xuewu Wang,Ziran Zhao,Jianping Cheng,Kejun Kang
Physics , 2015,
Abstract: Encoding readout methods based on different schemes have been successfully developed and tested with different types of position-sensitive detectors with stripe-readout structures. However, how to construct an encoding scheme in a more generic and systematic way is still under study. In this paper, we present a graph model for the encoding scheme. With this model, encoding schemes can be studied in a more systematic way. It is shown that by using an encoding readout method, a maximum of n(n-1)/2+1 stripes can be processed with n channels if n is odd, while a maximum of (n(n-2))/2+2 stripes can be processed with n channels if n is even. Furthermore, based on the model, the encoding scheme construction problem can be transformed into a problem in graph theory, in which the aim is to construct an Eulerian path such that the length of the shortest subcycle is as long as possible. A more generic approach to constructing the encoding scheme is found by solving the associated mathematical problem.
Human Identification by Gait Using Corner Points
Mridul Ghosh,Debotosh Bhattacharjee
International Journal of Image, Graphics and Signal Processing , 2012,
Abstract: Recently human gait has become a promising and very important biometric for identification. Current research on gait recognition is usually based on an average gait image or a silhouette sequence, or a motion structure model. In this paper, the information about gait is obtained from the disparity on time and space of the different parts of the silhouette. This paper proposes a gait recognition method using edge detection, identification of corner points from edges, and selection of control points out of those corner points. Here, the images of moving human figures are subtracted from background by simple background modeling technique to obtain binary silhouettes. A gait signature of a person is taken as silhouette images of a complete gait cycle. A complete gait cycle is then divided into different frames in such a way that the information of the person’s gait style can be represented fully. One given unknown gait cycle is compared with stored gait cycles in terms of a cyclic distances between control points of an image of input gait cycle with that of corresponding image of the stored gait cycle. Experimental results show that our method is encouraging in terms of recognition accuracy.
Gait variability: methods, modeling and meaning
Jeffrey M Hausdorff
Journal of NeuroEngineering and Rehabilitation , 2005, DOI: 10.1186/1743-0003-2-19
Abstract: Like most physiologic signals, measures of gait are not constants but rather fluctuate with time and change from one stride to the next, even when environmental and external conditions are fixed (Figure 1). In healthy adults, these stride-to-stride fluctuations are relatively small and the coefficient of variation of many gait parameters (e.g., gait speed, stride time) is on the order of just a few percent [1-3], testimony to the accuracy and reliability of the fine-tuned systems that regulate gait. Recently, the apparently "noisy" variations in stride length, stride time and gait speed have also been shown to display a hidden and unexpected fractal-like property [4-9]. These properties of gait exhibit long-range (power-law) correlations and a "memory" effect, such that fluctuations at any given moment are statistically related to those that occur over many different time scales. When the systems regulating gait are disturbed (e.g., as a result of certain diseases), movement control may be impaired leading to increased stride-to-stride fluctuations and/or alterations in their multiscale dynamics.The current series of the Journal of NeuroEngineering and Rehabilitation (JNER) is dedicated to gait variability. As guest editor of a collection of nine papers on this topic, I have had the opportunity to preview the wealth of information on stride-to-stride fluctuations in gait and the manifold ways in which gait variability may be analyzed. The articles in this collection cover a wide spectrum of themes ranging from methods for evaluating gait variability, animal and mathematical models investigating the factors that influence the variability of gait, and evaluations of the clinical utility of such measures. Altogether, these reports underscore the complex and fascinating nature of gait variability.To set the stage, it is helpful to briefly highlight previous work in this area. Earlier studies have demonstrated that:? Gait variability is a quantifiable feature of walking
Diffusion tensor imaging in elderly patients with idiopathic normal pressure hydrocephalus or Parkinson’s disease: diagnosis of gait abnormalities
Kohei Marumoto, Tetsuo Koyama, Masashi Hosomi, Norihiko Kodama, Hiroji Miyake, Kazuhisa Domen
Fluids and Barriers of the CNS , 2012, DOI: 10.1186/2045-8118-9-20
Abstract: The study involved 10 patients with INPH, 18 with PD, and 10 healthy individuals (control group). Fractional anisotropy (FA) of five brain areas was measured and compared among the three groups. In addition, the association of INPH and PD with gait capability, frontal lobe function, and FA of each brain area was evaluated.The INPH group had significantly lower FA for anterior thalamic radiation (ATR) and forceps minor (Fmin) as compared to the PD group. The gait capability correlated with ATR FA in the INPH and PD groups. We found that adding DTI to the diagnosis assisted the differential diagnosis of INPH from PD, beyond what could be inferred from ventricular size alone.We expect that DTI will provide a useful tool to support the differential diagnosis of INPH and PD and their respective severities.Idiopathic normal pressure hydrocephalus (INPH) is a syndrome which involves cognitive disorder, gait abnormalities, and urinary incontinence. INPH was first reported in 1965 by Hakim and Adams as a condition whose symptoms could be alleviated by a cerebrospinal fluid shunt [1]. In the past, patients with suspected INPH were frequently misdiagnosed. This over-diagnosis resulted in many unsuccessful surgeries or the development of postoperative complications and as a result, less attention was paid to INPH [2]. Under these conditions, three epidemiological studies were conducted on INPH, enabling estimation of its prevalence. The study by Hiraoka et al. found that 2.9% of community-dwelling elderly subjects showed radiological and clinical features consistent with INPH [3]. Using a similar procedure, Tanaka et al. reported possible INPH prevalence to be 1.4% [4] and Iseki et al. reported the prevalence of possible INPH to be 0.5%. Because symptoms appeared 4–8?years later in some of the initially symptom-free cases, the authors suggested the possibility that changes revealed by diagnostic imaging represent a precursor condition and proposed the concept “asymptomatic vent
Diagnosis of Appendicitis in Patients with Abnormal Position of the Appendix due to Mobile Caecum
Huseyin Toprak,Mehmet Bilgin,Musa Atay,Ercan Kocakoc
Case Reports in Surgery , 2012, DOI: 10.1155/2012/921382
Abstract: Acute appendicitis is usually diagnosed on the basis of signs, symptoms, clinical history, physical examination, and results of laboratory tests.The position of the appendix can vary considerably, both in relation to the caecum and because of the inconsistent position of the caecum itself, and may cause variable clinical symptoms. We present the CT findings of surgically proven acute appendicitis associated with atypically located caecum in two patients.
Diagnosis of Appendicitis in Patients with Abnormal Position of the Appendix due to Mobile Caecum  [PDF]
Huseyin Toprak,Mehmet Bilgin,Musa Atay,Ercan Kocakoc
Case Reports in Surgery , 2012, DOI: 10.1155/2012/921382
Abstract: Acute appendicitis is usually diagnosed on the basis of signs, symptoms, clinical history, physical examination, and results of laboratory tests.The position of the appendix can vary considerably, both in relation to the caecum and because of the inconsistent position of the caecum itself, and may cause variable clinical symptoms. We present the CT findings of surgically proven acute appendicitis associated with atypically located caecum in two patients. 1. Introduction Acute appendicitis is usually diagnosed on the basis of signs, symptoms, clinical history, physical examination, and results of laboratory tests. However, in patients with atypical clinical features, due to abnormal position of the appendix, imaging studies play an important role in preoperative diagnosis and determination of appropriate treatment. The position of the appendix can vary considerably, both in relation to the caecum and because of the inconsistent position of the caecum itself. The mobile caecum and ascending colon are rare congenital anomalies. Embryologically, the caecum and ascending colon are usually covered retroperitoneally by the posterior peritoneum. If this normal process altered or stopped, the caecum and ascending colon may be suspended on a mesentery that allows the colon to move freely [1, 2]. Therefore, it is important to identify the caecum on CT in patients with suspicion of acute appendicitis so that an abnormal appendiceal location will be recognized. The aim of this paper is to present the CT findings of acute appendicitis associated with atypically located caecum in two patients. 2. Case Report 2.1. Case??1 A 32-year-old woman was admitted to our hospital because of abdominal pain of one-day duration. The pain was localized in whole abdomen, constant and nonradiating. No other associated symptoms were noted. Physical examination revealed marked tenderness in the left upper and lower quadrant with moderate voluntary guarding. Her laboratory tests were normal except elevated white blood cell count of 15500/mL. Emergency US examination revealed normal uterus and bilateral ovaries, no signs of appendicitis in right lower quadrant, and colonic wall thickening. US revealed minimal free fluid in rectovesical pouch. US reported as normal by sonographer. Then, abdominopelvic CT examination with intravenous contrast material was performed (Asteion4-detector CT, Toshiba, Tokyo, Japan) to rule out other pathologies. Axial CT images demonstrate absence of caecum and right hemicolon in the right side of abdomen, normal position of superior mesenteric artery and vein
Geometry of straight lines pencils  [PDF]
Jani? Milan,Taniki? Dejan
Facta Universitatis Series : Architecture and Civil Engineering , 2002, DOI: 10.2298/fuace0204291j
Abstract: This paper considers a pencil of straight Unes in the Euclidean plane as well as the same pencil of straight lines in the projective plane where the projective geometry model M" is defined with its points forming the sets of (n-l) collinear points, whose supporting straight lines belong to the considered pencil of straight lines.
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