The Kinematic Analysis and Bistable Characteristics of the Winding Origami Structure

2021 ◽  
Author(s):  
Peng Liu ◽  
Jiayao Ma ◽  
Yan Chen ◽  
Lin Yuan ◽  
Haifeng Zhao ◽  
...  
Keyword(s):  
Mechanical Response ◽  
Transformation Method ◽  
Structural Deformation ◽  
Bistable System ◽  
Deformation Stage ◽  
Bistable Systems ◽  
New Ideas ◽  
Motion Characteristics ◽  
Two Stages ◽  
The Military

Abstract In the military and aerospace fields, bistable structures with adjustable or adaptive stiffness have been widely applied. Origami structures can be used to design bistable systems due to their unique geometrical characteristics. In this paper, we investigate a special design of winding origami, which consists of a square hub in the center and compactly folded panels around it. This delicate design provides the structure a bistable property. According to its motion characteristics, the folding process of the winding origami can be divided into two stages: the mechanism motion stage and the structural deformation stage. The D-H matrix method and truss transformation method were combined to analyze the kinematic relations, and the winding origami pattern was found to have one degree of freedom. At the structural deformation stage, the mechanical response and the local panel deformation were carefully studied via both experiments and finite element simulations, and a reasonable agreement was reached. It was observed that four creases exhibited a non-uniform folding pattern during the deformation process; that is, a portion of the crease was totally flattened while the rest remained folded. The origami structure’s unique kinematic and bistable features could possibly help provide some new ideas in designing a bistable system in the future.

The Catholic Church's Role in the Disintegration of the Spanish Colonial Empire. The Case of the Viceroyalty of New Granada

2007 ◽  
Vol 20 (1) ◽  
pp. 10-36 ◽  
Author(s):  
Ana Maria Bidegain
Keyword(s):  
Spanish Colonial ◽  
New Granada ◽  
Cultural Transformations ◽  
Starting Point ◽  
Colonial Empire ◽  
New Ideas ◽  
Popular Classes ◽  
Nueva Granada ◽  
Role Of Religion ◽  
The Military

AbstractThis article analyzes aspects of the complex process that led to independence in the Viceroyalty of Nueva Granada. It focuses on the role of religion and of social actors that have not been sufficiently taken into account in traditional historiography. The latter has paid much attention to political and economic aspects, but has disregarded other important changes that propelled the independence process, profound socio-cultural transformations and events that indicate the complexity of the process. First of all, this was not just a revolution from above and the historical periodization has to be reworked as a result of the Borbonic Reforms, with their leaning toward enlightenment. We must not consider the military uprisings as the starting point of the emancipation from the Spanish crown. Even though the colonial societies did not follow the same path as the European bourgeois revolutions with their proposed liberal perspectives, important changes did indeed happen, in which all social groups were implicated. From both the religious and particularly the women's historical perspective we can see the important transformations that took place. Examples are provided of how women of the popular classes triggered the process. Likewise, women amongst the educated elite, large sectors of the Creole clergy and some educational institutions were important agents of the ideological changes, by propagating new ideas. All these, in turn, paved the way for the further diversification of the ideological and religious landscape of Latin America during the independence period.

scholarly journals An Airport Knowledge-Based Method for Accurate Change Analysis of Airport Runways in VHR Remote Sensing Images

2020 ◽  
Vol 12 (19) ◽  
pp. 3163 ◽  
Author(s):  
Wei Ding ◽  
Jidong Wu
Keyword(s):  
Parallel Line ◽  
Extraction Methods ◽  
Analysis Method ◽  
Change Analysis ◽  
Multiple Features ◽  
Knowledge Based ◽  
Two Stages ◽  
Airport Runway ◽  
The Military ◽  
Very High

Due to the complexity of airport background and runway structure, the performances of most runway extraction methods are limited. Furthermore, at present, the military fields attach greater importance to semantic changes of some objects in the airport, but few studies have been done on this subject. To address these issues, this paper proposes an accurate runway change analysis method, which comprises two stages: airport runway extraction and runway change analysis. For the former stage, some airport knowledge, such as chevron markings and runway edge markings, are first applied in combination with multiple features of runways to improve the accuracy. In addition, the proposed method can accomplish airport runway extraction automatically. For the latter, semantic information and vector results of runway changes can be obtained simultaneously by comparing bi-temporal runway extraction results. In six test images with about 0.5-m spatial resolution, the average completeness of runway extraction is nearly 100%, and the average quality is nearly 89%. In addition, the final experiment using two sets of bi-temporal very high-resolution (VHR) images of runway changes demonstrated that semantic results obtained by our method are consistent with the real situation and the final accuracy is over 80%. Overall, the airport knowledge, especially chevron markings for runways and runway edge markings, are critical to runway recognition/detection, and multiple features of runways, such as shape and parallel line features, can further improve the completeness and accuracy of runway extraction. Finally, a small step has been taken in the study of runway semantic changes, which cannot be accomplished by change detection alone.

A Possibility Estimation Model and its Application

2013 ◽  
Vol 475-476 ◽  
pp. 423-427
Author(s):  
Lin Na Ji ◽  
Feng Bao Yang ◽  
Xiao Xia Wang
Keyword(s):  
Measurement Data ◽  
Engineering Application ◽  
Transformation Method ◽  
Estimation Model ◽  
Property Estimation ◽  
New Methods ◽  
Proposed Model ◽  
Practical Engineering ◽  
New Ideas ◽  
Possibility Distributions

Aiming at some uncertainty problems such as quality inspection of adhesive structure and risk assessment in the practical engineering application, a possibility estimation model is established. Firstly, according to the fuzziness, randomness and uncertainty of the measurement data, a transformation method of possibility distribution with non-single peak values and nonlinearity is proposed from probability density function. Secondly, for possibility distributions of measurement data of each sensor, a kind of possibility fusion rules is put forward, then the fusion distribution is estimated by the possibility mean. Finally the model is applied to the mechanical property estimation of adhesive structure, and the result forecasts the quality. The proposed model with strong applicability, not only provides convenience for the operations among possibility distributions, but also offers new ideas and new methods to deal with uncertain problems.

scholarly journals Exploiting nonlinearity in a flapping wing mechanism of a bio inspired micro air vehicle to enhance energy efficiency

2018 ◽  
Vol 148 ◽  
pp. 03007
Author(s):  
Ali Abolfathi
Keyword(s):  
Linear System ◽  
Peak Power ◽  
Insect Flight ◽  
Active Power ◽  
Bistable System ◽  
Flying Insects ◽  
Loading Function ◽  
Bistable Systems ◽  
Air Vehicle ◽  
Hardening Nonlinearity

In recent years, there was a great interest in developing flying drones with similar capabilities as flying insects. It is suggested that the flapping frequency of insects coincides with the resonance frequency of their flight mechanism to enhance the power consumptions. In this paper, the effect of nonlinearity in the flight mechanism on the power consumption is investigated. A simple nonlinear model of the insect flight mechanism is developed and normalised to study the effect of different parameters on its performance. Both bistable and hardening nonlinearity are considered. It is shown that for a harmonic loading, the bistable systems reach their peak power at lower frequencies when compared to the corresponding linear system. The maximum power factor of nonlinear oscillator would be lower than the liner one. It is also shown that the peak active power of the bistable system has a higher value than the linear system if the loading function is a pulse square signal.

Non-Chaotic Cross-Well State Transfer of Duffing-Holmes Type Bistable Systems

2017 ◽  
Author(s):  
Mehmet R. Simsek ◽  
Onur Bilgen
Keyword(s):  
Stable Equilibrium ◽  
Harmonic Excitation ◽  
Open Loop ◽  
Feedback Controller ◽  
Bistable System ◽  
Hybrid Controller ◽  
Positive Position Feedback ◽  
Bistable Systems ◽  
State Transfer ◽  
Position Feedback

A control strategy called hybrid position feedback control is applied to a bistable system to prevent multiple crossovers during actuation from one stable equilibrium to the other. The hybrid controller is based on a conventional positive position feedback controller. The controller uses the inertial properties of the structure around the stable positions to achieve large displacements by destabilizing a positive position feedback controller. Once the unstable equilibrium is reached, the controller is stabilized to converge to the target stable equilibrium. The bistable system under harmonic excitation and hybrid controller are investigated for its behavior. In addition, energy analysis of the system controlled by the hybrid controller is investigated using numerical time domain methods. The energy variance by parameters and the comparison between the open-loop system with harmonic excitation and the controlled system is investigated.

scholarly journals Understanding NHS hospital admissions in England, Scotland and Wales: data linkage to the King’s College Military Cohort Study

2017 ◽  
Vol 1 (1) ◽  
Author(s):  
Daniel Leightley ◽  
Zoe Chui ◽  
Laura Goodwin
Keyword(s):  
Cohort Study ◽  
Hospital Admissions ◽  
Health Providers ◽  
Regional Health ◽  
Coding Systems ◽  
King's College ◽  
Linkage Error ◽  
Local Coding ◽  
Two Stages ◽  
The Military

ABSTRACT ObjectiveSecondary health systems in the United Kingdom (UK) are unique for recording Outpatient, Inpatient and Accident & Emergency (A&E) visits in the form of electronic health (eHealth) records. Linking regional healthcare datasets is a problematic, further challenging when linking externally, such as to the King’s College Military Cohort Study (KCMCS). We introduce our methodology used for eRecord linkage. ApproacheHealth records from England, Scotland and Wales offer a variety of parameters such as admission/discharge date, diagnosis, treatment/procedure undertaken and the cost of treatment. To acquire eHealth records, unique patient identifiers: NHS number, forename, surname, sex and date of birth extracted from KCMCS were provided to each region. The KCMCS contains self-reported questionnaire results for 9,990 serving/ex-serving military personal, 8,602 participants consented to linkage. eHealth records prepared for linkage in two stages. First, admission and discharge date were checked to ensure a valid date. Second, episodes were checked for consistency, ensuring that no records for individual participants were duplicated. Data available varied based on the region, this disparity between regions can result in data type variation. Hence, linkage was performed on mutual variables to ensure a uniform admission history. Creation of the linked dataset was as follows. First, records and episodes relating to an individual were brought together, to create a personal admission history. Secondly, personal admission history were linked to the KCMCS. ResultsLinking to regional health datasets is not without its challenges. England, Scotland and Wales obtain, store and process eHealth records using different methodologies. A total of 6,336 (76.66%) participants were matched by regional health providers, with a total of 61,558 eHealth records. A total of 187 eHealth records were identified and discounted from linkage due to failure to meet criteria listed above. Verifying diagnoses completeness, Inpatient admissions were consistently code, with full completeness. Conversely, Outpatient admissions were poorly coded with 98% lacking any type of diagnosis. In addition, A&E records were sparsely coded; we identified four different regional and local coding systems to identify reason for admission. The eHealth records show promise for identifying health traits of the military. However, further work is required to identify synergy and overcome regional variations. ConclusionLinkage techniques provide new opportunities for exploring the health of serving and veteran population. However, quality of identifier and linkage error are still of major concern. Further, record completeness, diagnoses accuracy and data cleaning impact the data quality.

scholarly journals A TWO-STATE MODEL FOR NOISE-INDUCED RESONANCE IN BISTABLE SYSTEMS WITH DELAY

2005 ◽  
Vol 05 (02) ◽  
pp. 247-270 ◽  
Author(s):  
MARKUS FISCHER ◽  
PETER IMKELLER
Keyword(s):  
Discrete Time ◽  
Reference Model ◽  
Heuristic Method ◽  
State Model ◽  
Bistable System ◽  
Reduced Model ◽  
Effective Dynamics ◽  
Bistable Systems ◽  
Physics Literature ◽  
Two State Model

We discuss a simplified model for a symmetric bistable system with memory or delay, the reference model, which in the presence of noise, exhibits a phenomenon similar to what is known as stochastic resonance. The reference model is given by a one-dimensional parametrized stochastic differential equation with point delay, basic properties whereof we check. With the aim of capturing the effective dynamics and, in particular, the resonance-like behavior of the reference model, we construct a simplified or reduced model, the two-state model, first in discrete time, then in the limit of discrete time tending to continuous time. The main advantage of the reduced model is that it enables us to explicitly calculate the distribution of residence times which in turn can be used to characterize the phenomenon of noise-induced resonance. Drawing on what has been proposed in the physics literature, we outline a heuristic method for establishing the link between the two-state model and the reference model. The resonance characteristics developed for the reduced model can thus be applied to the original model.

A Method for Subsidence Monitoring of Similar Material Simulation Test in Coal Mining

2013 ◽  
Vol 765-767 ◽  
pp. 2172-2175 ◽  
Author(s):  
Min Tao ◽  
Xin Chen ◽  
Qiu Qi Ding
Keyword(s):  
Coordinate System ◽  
Coal Mining ◽  
Measurement System ◽  
Transformation Method ◽  
Reference Points ◽  
Similar Material ◽  
Simulation Test ◽  
Deformation Stage ◽  
Basic Stage ◽  
Similar Material Simulation

To accurately monitoring the subsidence of similar material simulation test in coal mining, a static deformation measurement system is proposed based on the digital image processing and photogrammetry techniques. Firstly pastes reference points and observation points on model frame and working face respectively. Before exploitation, calculates the 3D coordinates of those artificial points, transfers the default coordinate system to user defined coordinate system using 3-2-1 transformation method, and defines this stage as basic stage. Then start mining, records enough images from different position and angle, and calculates the 3D coordinates of the deformation stage. Finally aligns the single deformation stage to the basic stage, by tracking and comparing the 3D coordinates of the homonymous points, the subsidence of observation points are obtained. One similar material simulation tests were conducted which prove good performance of the proposed measurement system.

scholarly journals Stochastic Resonance in Bistable Systems: The Effect of Simultaneous Additive and Multiplicative Correlated Noises

1998 ◽  
Vol 12 (28) ◽  
pp. 1195-1202 ◽  
Author(s):  
Claudio J. Tessone ◽  
Horacio S. Wio
Keyword(s):  
Stochastic Resonance ◽  
Noise Intensity ◽  
Additive Noise ◽  
Signal To Noise Ratio ◽  
Bistable System ◽  
Signal To Noise ◽  
Multiplicative Noises ◽  
Bistable Systems ◽  
Resonance Response ◽  
Correlated Noises

We analyze the effect of the simultaneous presence of correlated additive and multiplicative noises on the stochastic resonance response of a modulated bistable system. We find that when the correlation parameter is also modulated, the system's response, measured through the output signal-to-noise ratio, becomes largely independent of the additive noise intensity.

Monitoring thermally induced structural deformation and framework decomposition of ZIF-8 through in situ temperature dependent measurements

2017 ◽  
Vol 19 (40) ◽  
pp. 27178-27183 ◽  
Author(s):  
Ben Xu ◽  
Yingjie Mei ◽  
Zhenyu Xiao ◽  
Zixi Kang ◽  
Rongming Wang ◽  
...  
Keyword(s):  
Structural Deformation ◽  
Lattice Expansion ◽  
Temperature Dependent ◽  
Thermally Induced ◽  
Deformation Stage ◽  
Expansion Stage ◽  
Transition Stages

ZIF-8 undergoes three transition stages, which are lattice expansion stage, “reversible” structural deformation stage, and decomposition/collapse stage.

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