internal disturbance
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2022 ◽  
Vol 355 ◽  
pp. 03009
Author(s):  
Rongyong Zhao ◽  
Ping Jia ◽  
Yan Wang ◽  
Cuiling Li ◽  
Chuanfeng Han ◽  
...  

Crowd merging is a complex process, and any sudden external or internal disturbance will destroy the stability of the crowd. The occurrence of abnormal behavior will affect the crowd flow process and inevitably affect the stability of the crowd flow system. The position information of the joint points is obtained through the OpenPose algorithm, and the kinematics characteristics of each node are studied. It is judged whether the number of pedestrians in the crowd and the scale of the building scene are greater than the empirical setting value based on engineering statistical data and expert experience. When the number of pedestrians is more than 2,000 and the total area of the passage is more than 2,000 square meters, the appropriate macro-dynamic model is selected. The Aw-Rascle (AR) fluid dynamics model is selected in this study. The joint point information obtained through the OpenPose is combined with the macroscopic fluid dynamics model to construct a macroscopic crowd flow dynamics model based on the pedestrian's abnormal posture.


2021 ◽  
pp. 1-21
Author(s):  
Zhuangsheng Zhu ◽  
Yaxin Gao ◽  
Hao Tan ◽  
Yue Jia ◽  
Qifei Xu

Abstract An aircraft wing is the carrier of imaging payload (interferometric synthetic aperture radar (SAR) or array SAR) of a high-resolution aerial remote sensing system, and high-precision estimation of wing deformation is the key. There are two main traditional modelling methods for wing deformation, namely stochastic theory modelling and material mechanics modelling only dealing with single disturbance, of which the model parameters are derived from empirical values. Aiming at the complex multi-source disturbance of an aircraft wing, this paper separately probes the influence of external disturbance (air disturbance) and internal disturbance (engine vibration) based on the real-time observation of sensors and classifies the wing deformation on the basis of auto-regressive (AR) modelling for parameter identification. With the authentic flight data of a certain types of aircraft, the experimental analysis shows that the wing deformation under the influence of engine vibration is the 14th-order AR model, and the wing deformation under the influence of turbulence is the fifth-order AR model. Meanwhile, this paper also provides an experimental verification idea for the wing deflection modelling built on the second- or third-order Markov model.


Author(s):  
Sergey Ovanesyan

The article deals with developing determination methods of coefficient parameters influencing economic system indices. It is necessary to assess how economic indices respond to external and internal disturbance while making reasonable managerial decisions within economic systems. The research aims to develop a tool alternative to flexibility, as the use of the latter is not comfortable when assessing economic systems performance due to the need to present influence factors variations in percentage terms. It is based on the sensitivity theory that resides in the fact that sensitivity functions are used to assess system responses following by calculating influence coefficients related. The developed theory and method can be used in different cost mana­gement tasks and break-even operations at enterprises and allow to carry out system analysis of different situations within an economic system at a micro-level. The article illustrates the suggested tool applied to the present value, which is one of the most important issues in economic theory. It should be noted that the article searches both the influence of separate factors such as annual rate, the number of years, expected value on the present value cost and the combined influence of the mentioned above on the cost, return rate and return value.


Author(s):  
Benedict Morrison

Complicating Articulation in Art Cinema argues that art cinema, unlike classical film, draws attention to its disjointed, multi-parted form, but that criticism has too frequently sought to explain this complexity away by stitching the parts together in totalizing readings. This stitching together has often relied on the assumption that complicated character explains articulated form and that the solution to art cinema’s puzzles lies in interpreting each film as the expression of a focalizing character’s internal disturbance. This book challenges this assumption. It argues that the attempt to explain formal complexity through this character-centric approach reduces formal achievements and enigmatic characters to inadequate approximations of one another. Reference to character cannot fully tame unschematic and unpredictable combinations of—and collisions between—contradictory levels of narration, clashing styles, discontinuously edited shots, jarring allusions, dislocated genre signifiers, and intermedial elements. Through close analyses of films by Roberto Rossellini, Robert Bresson, Luis Buñuel, Terence Davies, Peter Greenaway, and Kelly Reichardt, Complicating Articulation in Art Cinema offers an ethics of criticism that suggests that the politics of art cinema’s eccentric form are limited by character-centred readings. Each of the featured films presents inarticulate or muted characters, whose emotional and intellectual lives are unknowable, further complicating the relationship between character and form. This book argues that, by acknowledging this resistance to interpretation, critics can think in new ways about art cinema’s interrogation of the possibilities of knowledge.


2021 ◽  
Vol 10 (2) ◽  
pp. 619-631
Author(s):  
Sakol Nakdhamabhorn ◽  
M. Branesh Pillai ◽  
Jackrit Suthakorn

Minimally invasive surgery (MIS) is one of the most challenging tasks in surgical procedures due to the lack of visibility of the surgical area, instrument orientation, and depth perception. A tele-operated robot assisted minimally invasive surgery is developed to enhance a surgeon's hand dexterity and accuracy. To perform MIS, the surgeon controls a slave manipulator via a master manipulator, so the force feedback and motion feedback are required to imitate an amount of action and reaction force between master and slave manipulator. The complicated MIS requires more complex surgical manipulator with multi DOFs and multiple force feedback. The limitation of multiple DOFs force feedback is a bandwidth of torque sensors. Therefore, this study proposes a sensorless based 5-DOF Bilaterally controlled surgical manipulation. In this research disturbance observer (DOB) is used to identify the internal disturbance of the system, which is used to estimate the reaction torque. This research mainly focuses on a 5-DOF bilaterally controlled surgical manipulator to maintain a position and additional force. The result of torque error in contact motion is less than 2%, the non-contact motion error is not over 5%, and it is evident that the error is always less than 0.3% for the position response.


2021 ◽  
Vol 26 (1) ◽  
pp. 28-40
Author(s):  
Mohd Hafiz Abdul Satar ◽  
Wong Jen Nyap ◽  
Ahmad Zhafran Ahmad Mazlan

This paper focusses on the study of vibration attenuations for suspended handle models that are generated from power tools using an intelligent active force control (AFC) tuning strategy. Four types of control schemes are comparatively evaluated in suppressing the vibration of the handle, such as proportional-integral-derivative (PID), PID-AFC-crude approximation (AFCCA), PID-AFC-fuzzy logic (AFCFL) and PID-AFC-iterative learning method (AFCILM) control schemes. In all control schemes, the estimated counter force is generated from the actuating force and appropriate estimated mass M* that has been intelligently tuned to counter the system disturbances. The disturbances are modelled based on the power tools vibration (i.e., internal disturbance) and uncertainties during the operation (i.e., external disturbances). The study shows that the AFCCA scheme demonstrates the best performance when the M(CL) is tuned at 0.04 kg. For the AFCFL control scheme, the best response is obtained for the membership function of trapezoidal shape with M(FL) of 0.0403 kg, while for AFCILM control scheme, the best response is achieved when M(ILM) is tuned to 0.04 kg, with both parameters (A and B) set at 0.6. Overall, PID-AFCCA scheme shows the best performances for all of the case studies, followed by PID-AFCFL and PID-AFCILM. The findings of this study can benefit the power tool manufacturers and provide the basis of effectively intelligent controller design for the power tools application.


2021 ◽  
Vol 17 (3) ◽  
pp. 235
Author(s):  
Julianti . . ◽  
Rahmad . Husein ◽  
Anni Holila Pulungan

The purpose of this research was to help teachers to enrich their knowledge about Letterland strategies in teaching English vocabulary to young learners. The objective of this research was to investigate the types of problem faced by teachers while using Letterland strategies. This research applied descriptive qualitative design and the data gathered from the sentences of four teachers in Nursery class at a Singapore Pre-School, Medan. The techniques of collecting data were observation and interview. Then, the techniques in analyzing the data were condensation, data display, and conclusion drawing/verification. Based on the data analysis, it was found that there were two types of problem faced by all the teachers; an internal disturbance (54.55%),  and an external disturbance (45.45%). It was concluded that Letterland strategies were good for young learners in learning English vocabulary because it provided some fun activities that contained of multi-sensory based learning which they were able to see, hear, do, and touch it.         Keywords: English Vocabulary; Letterland Strategies; Young Learners


2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Fanwei Meng ◽  
Yuangong Sun

This paper focuses on the problem of state estimation for certain switched time-varying systems with time-varying delay and nonlinear disturbance. By using an integral inequality technique and a method used in positive systems, we have established several explicit criteria for state estimation of the system, which reduce to stability criteria for some particular cases. The involved nonlinear disturbance of the system takes more general form including both the internal disturbance and the external disturbance. Three numerical examples are also given to verify the validity of the obtained theoretical results.


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