Dynamic Pole Research Articles

A Dynamic Pole Motion Approach for Control of Nonlinear Hybrid Soft Legs: A Preliminary Study

Hybrid soft leg systems have been studied for advanced gaits of soft robots. However, it is challenging to analyze and control hybrid soft legs due to their nonlinearity. In this study, we adopted dynamic pole motion (DPM) to analyze stability of a nonlinear hybrid soft leg system with dynamic Routh’s stability criterion and to design a proper controller for the nonlinear system with an error-based adaptive controller (E-BAC). A typical hybrid soft leg system was taken as an example, as such a system can easily become unstable and needs a controller to get the system back to a stable state. Specifically, E-BAC was designed to control the unstable hybrid soft leg fast with a minimal overshoot. As a nonlinear controller, the implanted E-BAC in a feedback control system includes two dominant dynamic parameters: the dynamic position feedback Kpe,t and the dynamic velocity feedback Kve,t. These parameters were properly selected, and the feedback was continuously varying as a function of system error et, exhibiting an adaptive control behavior. The simulation shows that this approach for constructing an adaptive controller can yield a very fast response with no overshoot.

Impact of Covid-19 on Chiang Mai City Center Airport: a guideline for its urban regeneration

AbstractCovid-19 has brought Chiang Mai International Airport to a state of lethargy: the once tourism-oriented city in northern Thailand has seen its visitors arriving by air greatly reduced since the start of the pandemic. An analysis of airport spaces and usage shows that their core purposes are disrupted or at standstill. Using a qualitative approach, the purpose of this study is to propose a guideline to re-assess spaces of city-centered airports in times of crisis to help its urban regeneration. Urban recommendations are displayed for policymakers and then applied to Chiang Mai International airport context. Results found that temporary urban and architectural solutions are worth considering during the time of crisis and its unknown end date. Permanent solutions are also suggested to connect dynamic poles of the city with the airport area, leading to improve the reliance between Chiang Mai city and its airport. This prospective approach also sheds a light on the monofunctional purpose of the airport and relative seclusion issues due to single-use zoning in the fabrication of the city.

Hurtful Gifts? Trauma and Growth Transmission Among Local Clinicians in Postearthquake Haiti.

Although working with trauma survivors can be a source of both deleterious and positive transformations in mental health professionals, little is known about the experience of clinicians in shared traumatic contexts, particularly in the Global South, where most humanitarian crises occur. In collective disasters or armed conflicts, the personal and professional experiences of mental health staff inform each other, situating the clinical space at the intersection between singular and collective spheres. Drawing on an intersubjective and socioecological perspective, this qualitative study explored the ways in which working in a shared traumatic context affected mental health and psychosocial staff in postearthquake Haiti. We interviewed 22 local mental health workers in the capital, Port-au-Prince, 2.5 years after the 2010 disaster. We coded and thematically analyzed interviews using an iterative process, based on grounded theory principles. Thematic analysis uncovered four dynamic poles in clinicians' narratives: balancing duty and desire to help, experiencing fragility and strength, negotiating separation and connection, and sharing hurt and hope. Our findings suggest clinicians considered their work mainly as a source of strength in the face of adversity, whereas experiences of trauma and growth transmissions were mutual and intimately intertwined. We discuss the complexities of clinical work in shared traumatic settings as well as the dynamic interplay between professionals' experiences of suffering and growth. We conclude with recommendations on ways to involve local mental health clinicians in postdisaster contexts while addressing the special needs that they may have to process their own trauma.

Lane Detection and Classification for Forward Collision Warning System Based on Stereo Vision

This paper presents a lightweight stereo vision-based driving lane detection and classification system to achieve the ego-car's lateral positioning and forward collision warning to aid advanced driver assistance systems (ADAS). For lane detection, we design a self-adaptive traffic lanes model in Hough Space with a maximum likelihood angle and dynamic pole detection region of interests (ROIs), which is robust to road bumpiness, lane structure changing while the ego-car's driving and interferential markings on the ground. What's more, this model can be improved with geographic information system or electronic map to achieve more accurate results. Besides, the 3-D information acquired by stereo matching is used to generate an obstacle mask to reduce irrelevant objects' interfere and detect forward collision distance. For lane classification, a convolutional neural network is trained by using manually labeled ROI from KITTI data set to classify the left/right-side line of host lane so that we can provide significant information for lane changing strategy making in ADAS. Quantitative experimental evaluation shows good true positive rate on lane detection and classification with a real-time (15Hz) working speed. Experimental results also demonstrate a certain level of system robustness on variation of the environment.

Mellin amplitudes for fermionic conformal correlators

We define Mellin amplitudes for the fermion-scalar four point function and the fermion four point function. The Mellin amplitude thus defined has multiple components each associated with a tensor structure. In the case of three spacetime dimensions, we explicitly show that each component factorizes on dynamical poles onto components of the Mellin amplitudes for the corresponding three point functions. The novelty here is that for a given exchanged primary, each component of the Mellin amplitude may in general have more than one series of poles. We present a few examples of Mellin amplitudes for tree-level Witten diagrams and tree-level conformal Feynman integrals with fermionic legs, which illustrate the general properties.

Harmony search optimization for robust pole assignment in union regions for synthesizing feedback control systems

This paper is concerned with robust pole assignment optimization for synthesizing feedback control systems via state feedback or observer-based output feedback in specified union regions using the harmony search algorithm. By using exact pole placement theory and the harmony search algorithm, robust pole assignment for linear discrete-time systems or linear continuous-time systems in union regions can be converted into a global dynamical optimization problem. The robust measured indices are derived for robust union region stability constraints and a robust [Formula: see text] performance. For the nonlinear, robust measured indices, a set of dynamic poles and the corresponding feedback controllers can be obtained by global dynamic optimization based on the harmony search algorithm and the idea of robust exact pole assignment. One key merit of the proposed approach is that the radius or the position of the sub-regions can be arbitrarily specified according to the transient performance request. Furthermore, the eigenstructure of the closed-loop system matrix can be optimized with better robustness for the proposed approach. Finally, the simulation results for a discrete-time system and a continuous-time system demonstrate the effectiveness and superiority of the proposed method.

Determination of the Overshoot Scalar Control Systems with Transfer Zero and Binomial Law of Poles Distribution

Background/Objectives: One of the most popular approaches to the design of automatic control systems is the modal method of controller synthesis. Methods: Its peculiarity is that the requirements for management process quality are formalized by ensuring the desired location on a complex plane of a closed system poles. At that, the introduction of the modal controller makes no effect on the location of transmission zeros. Finding: However, it is known that many transition process quality indicators (e.g., overshoot value) depend not only on the poles but the zeros of the transfer function as well. In work presented here, we analyzed the dependence of overshoot value on the relative position of a dynamic system zeros and poles. Calculation formulas which allow determining the value of a positive or a negative overshoot without the development of transient response are obtained for a scalar system with one zero and the binomial pole distribution law. The dependence of overshoot value on the relative position of the transmission zero and the dynamic system poles is studied. The conditions are formulated, the implementation of which will provide in control system such an overshoot value which does not exceed a predetermined value. Conclusion: The obtained results can be used for further theoretical studies as well as in practice in solving problems of analysis and synthesis of control systems with a modal controller.

South-South Cooperation and the challenge of quantification, evaluation and assessment

The emergence of a more active South-South cooperation (SSC) constitutes on of the most relevant factors for change in the International arena in the last decades. It is an expression of the new role that emerging economies of the world embody in the ensemble of the International transactions and in the generation of dynamic poles of political and economic power. However, and even if for some experts of SSC it has consolidated as a cooperation mechanism, it still faces relevant challenges in order to recognize its potentials and its benefits. One of the most discussed challenges nowadays and maybe therefore the most necessary one is quantification, evaluation and assessment of SSC actions. The lack of regional and international consensus on the mechanisms, methodologies and spaces to register, quantify and evaluate SSC hampers its positioning, further away from the rhetoric, as an effective, efficient, horizontal and sustainable tool for development in the long term. This article claims that it is still necessary to go deeper into an analysis of SSC not only from the rhetoric, but also from material elements that allow us to gain knowledge of the value of this cooperation.

Searching for observable effects induced by anomalous triangle singularities

We investigate the anomalous triangle singularity (ATS) and its possible manifestations in various processes. We show that the ATS should have important impact on our understanding of the nature of some newly observed threshold states. Discussions on how to distinguish the ATS phenomena from genuine dynamic pole structures are presented.

Adaptive Control Augmentation for the Longitudinal Dynamics of a Hypersonic Glider

The descent longitudinal trajectory control methodology of a hypersonic glider to carry out a pullup maneuver is presented. A dynamic pole placement controller is implemented as the baseline controller. The baseline controller is augmented with an adaptive controller to cancel out the matched and unmatched uncertainties. The differences between the pole placement and the augmented pole placement controller are presented in terms of performance with the help of Monte Carlo simulations. The dynamic pole placement controller is shown to have robustness in the presence of time-invariant and time-varying errors in the aerodynamic coefficients, control surface, and gravimetric uncertainties. The augmented controller improves the performance of the baseline controller in the presence of these uncertainties. This is concluded with a reduction in the tracking error norm and the control surface norm, which is the energy of the deviation between the reference and real control signal; . The use of the adaptive controller, however, reduces the time delay margin of the system. The contribution of this paper lies in the application and determination of the performance of a piecewise constant adaptive augmentation setup to a nonminimum phase linear time-varying state feedback system.

The Emergence of Dynamic Contract Law

Contract law doctrines can be ranged along various spectra. One of these spectra runs from the static to the dynamic. A contract law doctrine lies at the static pole of this spectrum if its application turns entirely on what occurred at the moment in time when a contract was formed. A contract law doctrine lies at the dynamic pole if its application turns in significant part on a moving stream of events that precede, follow, or constitute the formation of a contract. Another spectrum runs from the binary to the multifaceted. Contract law doctrines are binary if they organize the experience within their scope into only two categories. Contract law doctrines are multifaceted if they organize the experience within their scope into several categories, including one or more intermediate categories. Classical contract law was a rigid, rather than a supple, instrument. Its rules were often responsive to neither the actual objectives of the parties, the actual facts and circumstances of the partiesâ transaction, nor the dynamic character of contracts. Instead, the rules of classical contract law were centered on a single moment in time, the moment of contract formation. accordingly, classical contract law doctrines were almost wholly static and also tended to be binary. The twentieth century witnessed the development of a modern contract law that has largely overthrown classical contract law. This overthrow has occurred in two ways. To begin with, in many cases modern contract law has reversed or fundamentally modified the rules of classical contract law. More important than the overthrow of specific rules of classical contract law, however, has been the overthrow of the deep structure of classical contract law. Where classical contract law had an overriding preference for rules that were objective and standardized, modern contract law has been highly flexible in adopting rules that are individualized and even subjective. Where classical contract law rules were typically binary, modern contract law rules are often multifaceted. Finally, where classical contract law was largely static, modern contact law is, in large part, dynamic. So, for example, static rules of interpretation have been replaced by dynamic rules that take into account events before and after the moment of contract formation; the static legal-duty rule has withered almost completely away, to be largely replaced by a dynamic modification regime that takes into account the value of ongoing reciprocity; a static judicial review of liquidated damages provisions is giving way to a dynamic review that takes account of the actual loss; and static offer-and-acceptance rules have been replaced by dynamic rules, such as the duty to negotiate in good faith.

X(3872) is not a true molecule

A solvable coordinate-space model is employed to study the \(c\bar{c}\) component of the X(3872) wave function, by coupling a confined 3 P 1 \(c\bar {c}\) state to the almost unbound S-wave \(D^{0}\overline{D}^{*0}\) channel via the 3 P 0 mechanism. The two-component wave function is calculated for different values of the binding energy and the transition radius a, always resulting in a significant \(c\bar{c}\) component. However, the long tail of the \(D^{0}\overline{D}^{*0}\) wave function, in the case of small binding, strongly limits the \(c\bar{c}\) probability, which roughly lies in the range 7–11 %, for the average experimental binding energy of 0.16 MeV and a between 2 and 3 GeV−1. Furthermore, a reasonable value of 7.8 fm is obtained for the X(3872) r.m.s. radius at the latter binding energy, as well as an S-wave \(D^{0}\overline{D}^{*0}\) scattering length of 11.6 fm. Finally, the \(\mathcal{S}\)-matrix pole trajectories as a function of coupling constant show that X(3872) can be generated either as a dynamical pole or as one connected to the bare \(c\bar{c}\) confinement spectrum, depending on details of the model. From these results we conclude that X(3872) is not a genuine meson–meson molecule, nor actually any other mesonic system with non-exotic quantum numbers, due to inevitable mixing with the corresponding quark–antiquark states.

In Situ Surveillance of Capacitive Pressure Transmitter Dynamic Poles

In this work, a methodology is proposed to find the dynamic poles of a capacitive pressure transmitter in order to enhance and extend the online surveillance of this type of sensor based on the response time measurement by applying noise analysis techniques and the dynamic data system procedure. Several measurements taken from a pressurized water reactor have been analyzed. The methodology proposes an autoregressive fit whose order is determined by the sensor dynamic poles. Nevertheless, the signals that have been analyzed could not be filtered properly in order to remove the plant noise; thus, this was considered as an additional pair of complex conjugate poles. With this methodology we have come up with the numerical value of the sensor second real pole in spite of its low influence on the sensor dynamic response. This opens up a more accurate online sensor surveillance since the previous methods were achieved by considering one real pole only.

Identification and robust limit-cycle-oscillation analysis of uncertain aeroelastic system

Model uncertainty directly affects the accuracy of robust flutter and limit-cycle-oscillation (LCO) analysis. Using a data-based method, the bounds of an uncertain block-oriented aeroelastic system with nonlinearity are obtained in the time domain. Then robust LCO analysis of the identified model set is performed. First, the proper orthonormal basis is constructed based on the on-line dynamic poles of the aeroelastic system. Accordingly, the identification problem of uncertain model is converted to a nonlinear optimization of the upper and lower bounds for uncertain parameters estimation. By replacing the identified memoryless nonlinear operators by its related sinusoidal-input describing function, the Linear Fractional Transformation (LFT) technique is applied to the modeling process. Finally, the structured singular value (µ) method is applied to robust LCO analysis. An example of a two-degree wing section is carried out to validate the framework above. Results indicate that the dynamic characteristics and model uncertainties of the aeroelastic system can be depicted by the identified uncertain model set. The robust LCO magnitude of pitch angle for the identified uncertain model is lower than that of the nominal model at the same velocity. This method can be applied to robust flutter and LCO prediction.

Design of an Error-Based Adaptive Controller for a Flexible Robot Arm Using Dynamic Pole Motion Approach

Design of an adaptive controller for complex dynamic systems is a big challenge faced by the researchers. In this paper, we introduce a novel concept ofdynamic pole motion(DPM) for the design of an error-based adaptive controller (E-BAC). The purpose of this novel design approach is to make the system response reasonably fast with no overshoot, where the system may be time varying and nonlinear with only partially known dynamics. The E-BAC is implanted in a system as a nonlinear controller with two dominant dynamic parameters: the dynamic position feedback and the dynamic velocity feedback. For illustrating the strength of this new approach, in this paper we give an example of a flexible robot with nonlinear dynamics. In the design of this feedback adaptive controller, parameters of the controller are designed as a function of the system error. The position feedbackKp(e,t)and the velocity feedbackKv(e,t)are continuously varying and formulated as a function of the system errore(t). This approach for formulating the adaptive controller yields a very fast response with no overshoot.

Failure of Flawed Utility Poles in Wind Gusts

The purpose of this study is to account for failures of wood utility poles in wind storms based on dynamic analysis and pole imperfections. The utility pole supporting multiple overhead transmission lines is modeled as a uniform Bernoulli–Euler cantilevered beam fixed at the base and subjected to three types of suddenly applied transverse loads that simulate a wind gust: a uniform pole pressure, a point load at the tip accounting for line and transformer drag, and another point load near midlength, accounting for drag on lines strung from that location. The dynamic pole moments are based on normal mode calculations rather than static calculations with a dynamic impact factor, and the critical flexural stresses include stress concentrations arising from pole imperfections such as holes, knots, and surface gouges. A case study illustrates the results for one of about 400 failed wood poles downed in a single New Jersey storm in 2003 with 107 km/h (67 m/h) wind gusts. Here, the critical pole stress based on the dynamic model and a hole imperfection exceeded the proportional limit stress of the wood. The predicted dynamic stresses are higher than those based on the National Electrical Safety Code.

Pole vault performance for anthropometric variability via a dynamical optimal control model

Optimal performance of a dynamical pole vault process was modeled as a constrained nonlinear optimization problem. That is, given a vaulter’s anthropomorphic data and approach speed, the vaulter chose a specific take-off angle, pole stiffness and gripping height in order to yield the greatest jumping height compromised by feasible bar-crossing velocities. The optimization problem was solved by nesting a technique of searching an input-to-output mapping arising from the vaulting trajectory and a method of nonlinear sequential quadratic programming (SQP). It was suggested from the optimization results that the body’s weight has an important influence on the vaulting performance beside the vaulter’s height and approach speed; the less skilled vaulter should gradually adopt a longer pole to improve the performance.

Dynamic Polynomial Combinants and Generalised Resultants: Parameterization according to Order and Degree

The theory of constant polynomial combinants has been well developed and it is linked to the linear part of the constant Determinantal Assignment problem that provides the unifying description of the pole and zero assignment problems in Linear Systems. Considering the case of dynamic pole, zero assignment problems leads to the emergence of dynamic polynomial combinants. This paper aims to develop the fundamentals of the theory of polynomial combinants by examining issues of their parameterization of dynamic polynomial combinants according to the notions of order and degree. Central to this study is the link of dynamic combinants to the theory of “Generalised Resultants”. The paper provides a description of the key spectral assignment problems, derives the conditions for arbitrary assignability of spectrum and introduces a complete parameterization of combinants and respective Generalised Resultants which is crucial for studying the minimal degree and order spectrum assignability.

System time-varying controller design via E.A. method

The new concepts of time-varying stabilizer via dynamic pole assignment and eigenstructure assignment method (E.A. method) are introduced in this paper. The theorem of dynamic pole assignment is obtained by employing the piecewise constant concept. By specifying the final eigenstructure, the parameters of the time-varying stabilizer can be determined via output controller is evaluated, and examples of a one-machine infinite-bussystem and a multimachine system in power system, are given to illustrate the advantages and effectiveness of the proposed technique.

A invenção da ordem: intelectuais católicos no Brasil

O trabalho investiga a gênese social e as características da emergência de uma experiência intelectual diretamente ligada à propagação da doutrina católica, que se configurou no Brasil entre as décadas de 1920 e 1940. A análise centra-se na atividade do Centro Dom Vital e da revista A Ordem, órgãos que expressam a militância política e cultural de Jackson de Figueiredo, principal líder laico do movimento. Em seguida, procura compreender como se dá a aproximação de artistas e literatos que incorporam o catolicismo como tema e forma de suas produções no interior dos círculos modernistas, a partir da análise da trajetória da tríade formada por Ismael Nery, Jorge de Lima e Murilo Mendes, que lograram inscrever sua produção no pólo mais dinâmico das realizações do período.