Non-Linear Analysis Research Papers - Academia.edu (original) (raw)

Introduction: “Sajdah”, a prostration position, is part of Muslim daily prayers. It seems
to have several effects on the brain and heart function. This study aimed to investigate the
prefrontal brain activity after 10 seconds of Sajdah in the direction of Qibla (the direction that
a Muslim prays) while putting the forehead on the ground.
Methods: Three women and two men participated in this pilot study. Linear (absolute and
relative power of θ (4-8Hz), α 1 (8-10 Hz), α 2 (10-12 Hz), β 1 (12-16 Hz), β 2 (16-20 Hz), β 3
(20-30 Hz), γ 1 (30-40 Hz), γ 2 (40-50 Hz) and non-linear features (approximate entropy, Katz
fractal dimension, Petrosian fractal dimension, spectral entropy, and sample entropy) from Fps
channel were calculated.
Results: The relative β to γ band, approximate and sample entropy, Petrosian fractal dimension
and mean of amplitude decreased in open eye state in women. While θ to γ bands in the closed
eye state decreased after Sajdah in women. The absolute γ bands in closed eye state and relative
β band in open eye state increased after Sajdah in men.
Conclusion: The pilot study showed that 10 seconds of Sajdah has effects on brain activity and
sometimes showed the opposite effect on genders.

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- Gender, EEG, Brain Activity, Non-Linear Analysis
- by umesh Rai
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- Electrical Engineering, Bond Graph, Simulink, Non-Linear Analysis

— Most of the steel structures in India are made of conventional steel sections (such as angle, channel and beam sections). However, new hollow steel sections (such as square and rectangular hollow sections) are gaining popularity in recent steel constructions due to a number of advantages such as its higher strength to weight ratio, better fire resistance properties, higher radius of gyration, lesser surface area, etc. This type of hollow sections can save cost up to 30 to 50% over the conventional steel sections (Tata Steel brochure, 2012). But unlike the conventional steel sections these hollow sections do not have standard connection details available in design code or in published literature. To overcome this problem the objective of the present study was identified to develop a suitable and economic connection detail between two square hollow sections which should be capable of transmitting forces smoothly and easy to be fabricated. To achieve the above objective, a square hollow beam to square hollow column connection was selected and modeled in commercial finite element software ABAQUS. This model was analyzed for nonlinear static (pushover) analysis considering a number of connection details. Following four alternative scheme of connection details were selected for this study: (i) using end-plate, (ii) using angle section, (iii) using channel sections, and (iv) using collar plates. The base model (rectangular hollow beam welded to one face of the rectangular hollow column) is also studied for reference. The performance of the selected connection details are compared and the best performing connection details is recommended for rectangular hollow beam-to-rectangular hollow column joints. The result shows that the load carrying capacity of the joint and the maximum deformation capacity is highly sensitive to the type of connection used. Also, the location of formation of plastic hinges in the structure (which can be at joint or at beam) depends highly on the type of connection used.

The basis of this study is the serviceability requirement which arouse long after the structural erection has been completed. Beams with web openings can be competitive in such cases, even though more alternatives to solid web beams such as stub girders, trusses etc. are available and height limitation is common problem faced by designers in multistoried buildings due to economic requirements and aesthetical considerations. Substantial spaces are normally required to enable the passage for large pipes and ducts beneath steel beams which leads to uneconomic floor heights. Though web openings could lead to a significant decrease in beam’s load carrying capacity depending on the adopted openings shape, size and location but can also be very helpful and important from the point of economy. So this study is concerned with the influence of the web opening on the strength of compressive elements and web crippling strength of steel sections. And the parametric analysis to be focused on size and location of opening. The paper summarizes the relevant study of provisions as given in the corresponding design standard and software based finite element analysis carried out by different authors and review the problem to arrive at meaningful conclusion for the study. And suggestion regarding the scope of further work.

In this modern era of 21st century the urbanization increases worldwide, in heavily populated cities the availability of land is becoming less and cost of land is becoming higher. In view of popularity & less availability of land, tall structures are only solutions for overcoming the problems. A tall structure should be designed to resist the lateral load like Earthquake force within the permissible limits set by Standards. Loads are mainly of two types that are Gravity Loads & Lateral Loads likes Earthquake load. Earthquake forces are further two types, Static Forces & Dynamic Forces. It would be linear and Non-linear also. Linear static analysis can be performed for Low Rise Structure & law earthquake zones only. For tall structure it is necessary to consider nonlinearity, which is generally observed in geometry & materials. Our study is based on " P-Delta " analysis which incorporates geometric nonlinearity in the analysis. The study will be performed on structural software ETABS.

- by GRD JOURNALS
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- Non-Linear Analysis, Tall Structures, Geometrical Nonlinearity, Lateral Loads

One of the most dangerous natural hazard is earthquake. The damages caused by earthquakes are uncountable. The occurrence of earthquake causes loss of lives and damages to manmade structures. One of the most widely accepted solution for reducing the damages caused by earthquake on Civil Engineering structures is Base isolation. Among the wide variety of base isolation systems, Lead rubber bearing plays an important role. The performance of lead rubber bearing during earthquake is evaluated by the finite element modelling and non-linear analysis in ANSYS workbench 17.0 in this study. The behaviour of lead rubber bearing is compared with that of laminated rubber bearing.

- by Omar El-Anwar
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- Civil Engineering, Algorithms, Project Management, Modeling
- by Adrian Fisher
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- Psychology, Cognitive Science, Sex, Child Development

We introduce the notion of reciprocally strongly convex functions and we present some examples and properties of them. We also prove that two real functions f and g, defined on a real interval [a, b], satisfy f (xy/( tx + (1 − t)y)) ≤ tg (y) + (1 − t)g (x) − ct(1 − t) (1/ x − 1/ y)^ 2 , for all x, y ∈ [a, b] and t ∈ [0, 1] iff there exists a reciprocally strongly convex function h : [a, b] → R such that f (x) ≤ h (x) ≤ g (x) for all x ∈ [a, b]. Finally, we obtain an approximate convexity result for reciprocally strongly convex functions; namely we prove a stability result of Hyers-Ulam type for this class of functions.

The widespread brittle failure of welded beam-to-column connections caused by the 1994 Northridge and 1995 Kobe earthquakes highlighted the need for retrofitting measures effective in reducing the strength demand imposed on connections under cyclic loading. Researchers presented the reduced beam section (RBS) as a viable option to create a weak zone away from the connection, aiding the prevention of brittle failure at the connection weld. More recently, an alternative connection known as a reduced web section (RWS) has been developed as a potential replacement, and initial studies show ideal performance in terms of rotational capacity and ductility. This study performs a series of non-linear static pushover analyses using a modal load case on three steel moment-resisting frames of 4-, 8-, and 16-storeys. The frames are studied with three different connection arrangements; fully fixed moment connections, RBSs and RWSs, in order to compare the differences in capacity curves, inter-storey drifts, and plastic hinge formation. The seismic-resistant connections have been modeled as non-linear hinges in ETABS, and their behavior has been defined by moment-rotation curves presented in previous recent research studies. The frames are displacement controlled to the maximum displacement anticipated in an earthquake with ground motions having a 2% probability of being exceeded in 50 years. The study concludes that RWSs perform satisfactorily when compared with frames with fully fixed moment connections in terms of providing consistent inter-storey drifts without drastic changes in drift between adjacent storeys in low-to mid-rise frames, without significantly compromising the overall strength capacity of the frames. The use of RWSs in taller frames causes an increase in inter-storey drifts in the lower storeys, as well as causing a large reduction in strength capacity (33%). Frames with RWSs behave comparably to frames with RBSs and are deemed a suitable replacement.

- by amin janghorbani
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- Artificial Intelligence, Machine Learning, EEG, Chaos
- by Anis Shatnawi
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- Civil Engineering, Storage structures, Non-Linear Analysis

Thirty-Seven undergraduate students (23 engineering students, 14 social and human science students) had their electroencephalogram (EEG) recorded during the performing of mental rotation and recognition of virtual tridimensional geometric patterns tasks. Their spatial cognition degree of development was assessed by a BPR-5 psychological test. The Largest Lyapunov Exponent (LLE) was calculated from each of the 8 EEG channels recorded: FP1, FP2, F3, F4, T3, T4, P3, and P4. The LLEs were used as inputs for 3 different artificial neural networks topologies: i) multilayer perceptron, ii) radial base function, and iii) voted perceptron. Then the best results obtained using each topology is compared with the results obtained using the other topologies.

- by Guilherme Maron
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- EEG, Electroencephalography, Cognitive Neuroscience, Artificial Neural Networks

Bu çalışmada, İstanbul’da başlayan ve sürmekte olan kentsel dönüşüm projesi kapsamında inşa edilen konut türü binaların hemen hemen tümünde kullanılan taşıyıcı sistem modelinin deprem performansının araştırılması amaçlanmıştır. Bahsedilen taşıyıcı sistem modelinde, kolon ve perdelerden oluşan düşey ve yatay yük taşıyıcı elemanlar, dişli döşemeler ve bu döşemeler içinde teşkil edilen yassı kirişler ile birbirine bağlanmaktadır. Bu tür binaları temsil edecek şekilde seçilmiş orta yükseklikte bir betonarme bina güncel yönetmeliklere göre boyutlandırılmıştır. Daha sonra bu binanın deprem performansı araştırılmıştır. Bu çalışmadan elde edilen sonuçlar bu tür binaların yeterli deprem güvenliğini sağlamadığı yönündedir.

- by tugrul akyildiz and +1
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- Performance Based Earthquake Engineering, Non-Linear Analysis, Earthquake Resistant Buildings
- by Stefano Milani
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- ASME, Pressure Vessel Design, Non-Linear Analysis, Linear and Nonlinear Analyses

We performed a seismic vulnerability assessment of the city of Constantine
(Algeria) using the Risk-UE and datamining-based methods [association rule learning
(ARL)]. The ARL method consists in establishing relationships between building attributes
(number of stories or building age) and the vulnerability classes of the European Macroseismic
Scale, EMS98. This approach avoids the costly process of drawing up an inventory
of building characteristics in the ﬁeld, which often discourages the assessment of seismic
risk initiatives in weak to moderate seismic-prone regions. We showed that the accuracy of
the assessment is independent of the subset used for the learning phase leading to development
of the Constantine vulnerability proxy. Considering only two attributes, the vulnerability
assignment is equal to about 75%, reaching 99% if material is added to the
attributes considered. Comparison of Risk-UE and ARL results revealed a reliable
assessment of vulnerability, the differences having only a slight impact on the probability
of exceeding the damage level computed by EMS98 or Risk-UE in Constantine. The
results of this study suggest that the ARL-based vulnerability proxy is efﬁcient and could
be applied to the rest of Algeria.

- by James Maina
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- Civil Engineering, Linear Elasticity, Numerical Analysis, South Africa

The main features of early rehabilitation after severe brain damage are discussed in the article. The most important component for the entire rehabilitation process and the subsequent life of the patient is considered restoration of consciousness. Team seems to be a key factor in regaining consciousness along with the restoration of vital functions, movement, cognition, and behavior in these patients. The basic working principle is feedback to any minimal movement, or vegetative signal of a patient, beyond specific professional targets. A network of feedbacks with a patient and between professionals, that is, free flow of information, can be built only through work in a transdisciplinary team mode. The net of feedbacks with the patient and inter-professional ones builds up the team as Non-linear Complex System. Characteristics of "Team-Patient" system status are energy, entropy, and complexity. Teamwork techniques are individualized for resulting optimization of system condition. Increase of complexity is a powerful tool for propulsion of recovery process. Then consciousness may appear as a result of system self-organization. The article reflects the authors' view on interdisciplinary studies of the phenomenon of consciousness through its impairment and recovery. It focuses on the work of the "proper rehabilitation team", the mechanisms of its action and methods for researching the occurring phenomena.

- by Olga Maksakova
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- Self-Organization, Teamwork, Mind-body problem, Non-Linear Analysis

Se estudia la existencia de soluciones radiales de problemas semilineales elípticos indefinidos sobre la bola unidad de R n (n ≥ 3) con condiciones de frontera de Dirichlet, cuyo término no lineal es de la forma λm(|x|)f (u) donde m(|·|) es radialmente simétrica, discontinua y cambia de signo. Este estudio se realiza utilizando técnicas variacionales y en especial el "Lema del Paso de Montaña" de Ambrosetti-Rabinowitz. Palabras clave. Ecuación semilineal, Problema a valores en la frontera, Solución radial, Dominio simétrico, Bola unidad, Cambio de signo.
Abstract We study the existence of radial solutions of indefinite semilinear elliptic equations in the unit ball in R n (n ≥ 3) with Dirichlet boundary conditions, whose nonlinear term has the form λm(|x|)f (u) where m(| · |) is radially symmetric, discontinuous and changes sign. This study is realized using variational tecniques and especially the Ambrosetti-Rabinowitz's "Mountain Pass Lemma".

The Border Gateway Protocol (BGP) is the default Internet routing protocol that manages connectivity among Autonomous Systems (ASes). Although BGP disruptions are rare, when they occur the consequences can be very damaging. Consequently there has been considerable effort aimed at understanding what is normal and abnormal BGP traffic and, in so doing, enable potentially disruptive anomalous traffic to be identified quickly. In this paper, we make two contributions. We show that over time BGP messages from BGP speakers have deterministic, recurrence and non-linear properties, then build on this insight to introduce the idea of using Recurrence Quantification Analysis (RQA) to detect BGP instability. RQA can be used to provide rapid identification of traffic anomalies that can lead to BGP instability. Furthermore, RQA is able to detect abnormal behaviours that may pass without observation.

- by Bahaa Al-Musawi
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- Non-Linear Analysis, BGP Protocol