Adaptive Nonlinear PD Controller of Two-Wheeled Self-Balancing Robot with External Force

This paper proposes an adaptive nonlinear proportional-derivative(ANPD)controller for a two-wheeled self-balancing robot(TWSB)modeled by the Lagrange equation with external forces.The proposed control scheme is designed based on the combination of a nonlinear proportional-derivative(NPD)controller and a genetic algorithm,in which the proportional-derivative(PD)parameters are updated online based on the tracking error and the preset error threshold.In addition,the genetic algorithm is employed to adaptively select initial controller parameters,contributing to system stability and improved control accuracy.The proposed controller is basic in design yet simple to implement.The ANPD controller has the advantage of being computationally lightweight and providing high robustness against external forces.The stability of the closed-loop system is rigorously analyzed and verified using Lyapunov theory,providing theoretical assurance of its robustness.Simulations and experimental results show that the TWSB robot with the proposed ANPD controller achieves quick balance and tracks target values with very small errors,demonstrating the effectiveness and performance of the proposed controller.The proposed ANPD controller demonstrates significant improvements in balancing and tracking performance for two-wheeled self-balancing robots,which has great applicability in the field of robot control systems.This represents a promising solution for applications requiring precise and stable motion control under varying external conditions.

Nonlinear Pushover Analysis of the Influences on RC Footing for the External Elevator Well

In contemporary society, reducing carbon dioxide emissions and achieving sustainable development are paramount goals. One effective approach is to preserve existing RC (Reinforced Concrete) buildings rather than demolishing them for new construction. However, a significant challenge arises from the lack of elevator designs in many of these existing RC buildings. Adding an external elevator becomes crucial to solving accessibility issues, enhancing property value, and satisfying modern residential buildings using convenient requirements. However, the structural performance of external elevator wells remains understudied. This research is designed by the actual external elevator project into existing RC buildings in Jinzhong Rd, Shanghai City. Specifically, this research examines five different external elevator wells under nonlinear pushover analysis, each varying in the height of the RC (Reinforced Concrete) footing. By analyzing plastic hinge states, performance points, capacity curves, spectrum curves, layer displacement, and drift ratio, this research aims to provide a comprehensive understanding of how these structures of the external elevator well respond to seismic events. The findings are expected to serve as a valuable reference for future external elevator projects, ensuring the external elevator designs meet the seismic requirements. By emphasizing seismic resistance in the design phase, the research aims to enhance the overall safety and longevity of external elevator systems integrated into existing RC buildings.

Research Progress of Traditional Chinese Medicine External Treatment for Cancer Pain

Cancer pain,as a common complication in patients with malignant tumors,is regarded as the fifth vital sign.The involvement of traditional Chinese medicine(TCM)in the treatment of malignant tumors has become a distinctive feature of oncology treatment in China.It is also an important component of cancer pain management.TCM analgesic treatments include various methods,such as internal medicine and external therapies.External analgesic therapies,in particular,are significant methods in TCM pain management and offer both local treatment and systemic regulation.These methods are simple,easy to perform,and non-invasive.They can enhance pain relief effects while reducing the difficulty of oral medication intake and avoiding adverse gastrointestinal reactions,providing new perspectives and approaches for cancer pain treatment with broad development prospects.This article provides a review of the external TCM therapies for cancer pain to share with peers in the field.

Current Research Status of Traditional Chinese Medicine External Treatment for Diarrhea Type Irritable Bowel Syndrome

Irritable bowel syndrome(IBS-D)with diarrhea is a common gastrointestinal functional disease in clinical practice,which seriously affects the quality of life of patients.Cur‐rently,Western medicine has poor therapeutic effects,while traditional Chinese medi‐cine has unique advantages in relieving IBS-D symptoms and preventing recurrence.In recent years,especially with external treatment of traditional Chinese medicine,it has become a new treatment direction in clinical practice and has achieved good therapeutic effects.This article will provide a review of recent research on the treatment of IBS-D using traditional Chinese medicine external treatment methods.

Nonlinear dynamic analysis of cantilevered piezoelectric energy harvesters under simultaneous parametric and external excitations

The nonlinear dynamics of cantilevered piezoelectric beams is investigated under simultaneous parametric and external excitations. The beam is composed of a substrate and two piezoelectric layers and assumed as an Euler-Bernoulli model with inextensible deformation. A nonlinear distributed parameter model of cantilevered piezoelectric energy harvesters is proposed using the generalized Hamilton＇s principle. The proposed model includes geometric and inertia nonlinearity, but neglects the material nonlinearity. Using the Galerkin decomposition method and harmonic balance method, analytical expressions of the frequency-response curves are presented when the first bending mode of the beam plays a dominant role. Using these expressions, we investigate the effects of the damping, load resistance, electromechanical coupling, and excitation amplitude on the frequency-response curves. We also study the difference between the nonlinear lumped-parameter and distributed- parameter model for predicting the performance of the energy harvesting system. Only in the case of parametric excitation, we demonstrate that the energy harvesting system has an initiation excitation threshold below which no energy can be harvested. We also illustrate that the damping and load resistance affect the initiation excitation threshold.

Effective response of nonlinear cylindrical coated composites under external AC and DC electric field

This paper uses the perturbation method to study effective response of nonlinear cylindrical coated composites. Under the external AC and DC electric field Ea （1 ＋sin ωt）, the local potentials of composites at all harmonic frequencies are induced. An effective nonlinear response to composite is given for the cylindrical coated inclusions in the dilute limit.

Effective response in nonlinear spherical coated composites under external AC and DC electric fields

By using the perturbation method, effective nonlinear direct current （DC） and alternating current （AC） responses of nonlinear composites with spherical coated inclusions randomly embedded in a host medium are studied under the action of an external electric field Ea = E0 ＋ E1 sinωt ＋ E3 sin 3ωt with different amplitudes and frequencies. The local potentials of composites at all harmonics are given in the inclusion particles and the host regions. All effective nonlinear responses to composites and the relationship between the effective nonlinear responses at all harmonics are also deduced for the spherical coated inclusions in a dilute limit.

PD-type iterative learning control for nonlinear time-delay system with external disturbance

The PD-type iterative learning control design of a class of affine nonlinear time-delay systems with external disturbances is considered. Sufficient conditions guaranteeing the convergence of the n-norm of the tracking error are derived. It is shown that the system outputs can be guaranteed to converge to desired trajectories in the absence of external disturbances and output measurement noises. And in the presence of state disturbances and measurement noises, the tracking error will be bounded uniformly. A numerical simulation example is presented to validate the effectiveness of the proposed scheme.

Operational definitions and measurement of externalizing behavior problems:An integrative review including research models and clinical diagnostic systems

Measurement of externalizing disorders such as antisocial disorders,attentiondeficit/hyperactivity disorder or borderline disorder have relevant implications for the daily lives of people with these disorders.While the Diagnostic and Statistical Manual of Mental Disorders(DSM)and the International Classification of Diseases(ICD)have provided the diagnostic framework for decades,recent dimensional frameworks question the categorical approach of psychopathology,inherent in traditional nosotaxies.Tests and instruments develop under the DSM or ICD framework preferentially adopt this categorical approach,providing diagnostic labels.In contrast,dimensional measurement instruments provide an individualized profile for the domains that comprise the externalizing spectrum,but are less widely used in practice.Current paper aims to review the operational definitions of externalizing disorders defined under these different frameworks,revise the different measurement alternatives existing,and provide an integrative operational definition.First,an analysis of the operational definition of externalizing disorders among the DSM/ICD diagnostic systems and the recent Hierarchical Taxonomy of Psychopathology(HiTOP)model is carried out.Then,in order to analyze the coverage of operational definitions found,a description of measurement instruments among each conceptualization is provided.Three phases in the development of the ICD and DSM diagnosis systems can be observed with direct implications for measurement.ICD and DSM versions have progressively introduced systematicity,providing more detailed descriptions of diagnostic criteria and categories that ease the measurement instrument development.However,it is questioned whether the DSM/ICD systems adequately modelize externalizing disorders,and therefore their measurement.More recent theoretical approaches,such as the HiTOP model seek to overcome some of the criticism raised towards the classification systems.Nevertheless,several issues concerning this model raise mesasurement challenges.A revision of the instruments underneath each approach shows incomplete coverage of externalizing disorders among the existing instruments.Efforts to bring nosotaxies together with other theoretical models of psychopathology and personality are still needed.The integrative operational definition of externalizing disorders provided may help to gather clinical practice and research.

Effect of Manufacturing Errors on Static Characteristics of Externally Pressurized Spherical Air Bearings

Externally pressurized spherical air bearings are the key component of the three-axis air bearing table, and the manufacturing errors of the bearing affects the performance of the air bearing table. However, the manufacturing errors are unavoidable, and the pursuit to enhance the manufacturing accuracy will increase the cost greatly. In order to provide some theoretical guideline for the tolerance choice in the design of the externally pressurized spherical air bearings with inherent compensation, the effects of several manufacturing errors on the static characteristics of the air bearing are studied. Due to the complex geometry of the computational domain, an unstructured meshing technology is used for mesh generation. A finite-volume method is adopted to discretize the three-dimensional steady-state compressible Navier-Stokes equations. A modified SIMPLE algorithm which is suitable for compressible flows is applied to solve the discretized governing equations. The effects of the dimension error and the roundness error of the ball head and the ball socket on the static characteristics are investigated. The investigation result shows that the positive dimension error and the oblate spheroid-type roundness error of the ball head as well as the negative dimension error and the prolate spheroid-type roundness error of the ball socket can improve the bearing capacity and static stiffness of the air bearings by reducing the mass flow. The calculation method proposed in this paper fits well for the general principle, which can be extended to the characteristics analysis of other air bearings.

Research of Risk Identification and Prevention of Underground Pressure Pipelines Damage Caused by External Disturbance

External disturbance is an important cause of underground pressure pipeline damage,which leads to accidents,and it is crucial to study the risk of damage caused by external disturbance and come up with proper prevention and control measures.We reviewed literature on risk identification of underground pressure pipelines damage due to external disturbance was conducted,and a list of risk factors was formed.Based on the list of risk factors,fault tree analysis was carried out on underground pressure pipelines damage caused by external disturbances,and risk prevention and control measures were proposed through the calculation of minimum cut sets,minimum path sets,and structural importance,in hopes of providing reference for the normal operation of underground pressure pipelines.

Nonlinear Dynamic Analysis of Coupled Gear-Rotor-Bearing System with the Effect of Internal and External Excitations

Extensive studies on nonlinear dynamics of gear systems with internal excitation or external excitation respectively have been carried out. However, the nonlinear characteristics of gear systems under combined internal and external excitations are scarcely investigated. An eight-degree-of-freedom（8-DOF） nonlinear spur gear-rotor-bearing model, which contains backlash, transmission error, eccentricity, gravity and input/output torque, is established, and the coupled lateral-torsional vibration characteristics are studied. Based on the equations of motion, the coupled spur gear-rotor-bearing system（SGRBS） is investigated using the Runge-Kutta numerical method, and the effects of rotational speed, error fluctuation and load fluctuation on the dynamic responses are explored. The results show that a diverse range of nonlinear dynamic characteristics such as periodic motion, quasi-periodic motion, chaotic behaviors and impacts exhibited in the system are strongly attributed to the interaction between internal and external excitations. Significantly, the changing rotational speed could effectively control the vibration of the system. Vibration level increases with the increasing error fluctuation. Whereas the load fluctuation has an influence on the nonlinear dynamic characteristics and the increasing excitation force amplitude makes the vibration amplitude increase, the chaotic motion may be restricted. The proposed model and numerical results can be used for diagnosis of faults and vibration control of practical SGRBS.

Effectiveness of combining manual external defibrillator and automated external defibrillator training for third-year nurse students

Purpose:To assess the effectiveness of automated external defibrillator(AED)and manual external defibrillator(MED)training for third-year nurse students.Methods:We conducted post-demonstration and post-practice evaluation for MED defibrillation,and pre-training,post-demonstration,and post-practice evaluation for AED defibrillation.Results:Following MED training,time and confidence to defibrillate were improved significantly post-practice(p<0.001,p<0.001,respectively).In post-demonstration and postpractice evaluation,most students placed electrodes correctly(84.21%vs.80.70%),cleared before defibrillation(75.44%vs.89.47%),and performed cardiopulmonary resuscitation immediately after defibrillation(81.81%vs.94.44%);the evaluations were not statistically different(p=0.806,p=0.094,p=0.198,respectively).For AED training,time and confidence to defibrillate post-demonstration and post-practice were significantly improved(p<0.001 vs.p<0.001;p<0.001 vs.p<0.001,respectively)compared to that of pre-training;there was no obvious difference between the post-demonstration and postpractice evaluation(p=0.235,=0.346,respectively).Post-AED demonstration,most students could place electrodes correctly(85.96%),clear(91.23%),and perform CPR immediately after defibrillation(85.96%),which remained at a high level post-practice(94.74%,85.96%,82.46%,respectively);there was no significant difference between the two evaluations(p=0.203,p=0.557,p=0.776,respectively).Conclusion:Combining MED and AED defibrillation training is effective and feasible for third-year nurse students.Minimal training is effective for AED,while MED requires additional practice.

Capillary Hemangioma of the Middle Ear and External Auditory Canal:a Case Report

We report a case of capillary hemangiomsa that involved the entire middle ear space,external auditory canal(EAC) and tympanic antrum.Symptoms in the case included ear fullness,hearing loss,otalgia and otorrhea.The case was misdiagnosed as recurrent chronic otitis media with granulation preoperatively.A diagnosis of capillary hemangioma was established by postoperative histological examination.The management of capillary hemangioma of the middle ear and external auditory canal is discussed,with a review of the literature.Because of its variable and sometimes misleading clinical presentation,hemangioma can initially be misdiagnosed as other lesions.Therefore,a high index of suspicion is necessary for early and accurate diagnosis.

EXACT SOLUTIONS FOR STATIONARY RESPONSES OF SEVERAL CLASSES OF NONLINEAR SYSTEMS TO PARAMETRIC AND/OR EXTERNAL WHITE NOISE EXCITATIONS

The exact solutions for stationary responses of one class of the second order and three classes of higher order nonlinear systems to parametric and/or external while noise excitations are constructed by using Fokkcr-Planck-Kolmogorov et/ualion approach. The conditions for the existence and uniqueness and the behavior of the solutions are discussed. All the systems under consideration are characterized by the dependence ofnonconservative fqrces on the first integrals of the corresponding conservative systems and arc catted generalized-energy-dependent f G.E.D.) systems. It is shown taht for each of the four classes of G.E.D. nonlinear stochastic systems there is a family of non-G.E.D. systems which are equivalent to the G.E.D. system in the sense of having identical stationary solution. The way to find the equivalent stochastic systems for a given G.E.D. system is indicated and. as an example, the equivalent stochastic systems for the second order G.E. D. nonlinear stochastic system are given. It is pointed out and illustrated with example that the exact stationary solutions for many non-G.E.D. nonlinear stochastic systems may he found by searching the equivalent G.E.D. systems.

BIFURCATION IN A NONLINEAR DUFFING SYSTEM WITHMULTI-FREQUENCY EXTERNAL PERIODIC FORCES

By introducing nonlinear frequency, using Floquet theory and referring to the characteristics of the solution when it passes through the transition boundaries, all kinds of bifurcation modes and their transition boundaries of Duffing equation with two periodic excitations as well as the possible ways to chaos are studied in this paper.

Sixty-one Cases of Angina Pectoris due to Coronary Heart Disease Treated by External Use of the Paste of Nitrum and Realgar Powder on Zhiyang(GV 9)

In order to inquire into the therapeutic effects of Xiao Shi Xiong Huang San (硝石雄黄散the Nitrum and Realgar Powder), one of the Dunhuang Prescription, on angina pectoris due to coronary heart disease (APCHD), the authors have treated 61 cases of APCHD by externally applying paste of the powder on Zhiyang (GV 9), with another 30 cases of APCHD treated with the nitroglycerin paste on Zhiyang as the controls. The results showed that the total effective rate was 82% and markedly effective rate 31.2% in the treatment group (the Paste of Nitrum and Realgar Powder), and the total effective rate was 46.6% and markedly effective rate 23.2% in the control group (the nitroglycerin paste). The difference in therapeutic effects between the two groups was very significant (P<0.01), indicating that the therapeutic effect of the former was significantly superior to that of the latter.

China's External Economic Environment in the Early New Century

Four Changes in World EconomyFirst,a new round of global economic growth is under way.In 2000,oil pricerose rapidly,stoek markets and exchange rates remained volatile and interestrates went up.All these disadvantages did not undermine the foundations of worldeconomy,and the average growth rate of global gross domestic product(GDP)

STUDY AND APPLICATION ABOUT COMPUTED SYSTEM FOR EXTERNAL CARDIAC MASSAGE, MONITOR OF HEART AND BODY TEMPERATURE

Objective:To make and study computed system for external cardiac massage,monitor of heart and body temperature and observe its clinical effect.Method:The system was made and applied.Result:The effect of system was obvious.Conclusion: The system was an effective clinical equipment in treatment of patient with cardiac arrest.

Application of high resolution computer tomography in external ear canal cholesteatoma diagnosis

Objective: To evaluate High Resolution Computer Tomography(HRCT) in the diagnosis of external ear canal cholesteatoma.Methods: In this retrospective study, HRCTs of 27 patients with external ear canal cholesteatoma were reviewed. The changes in the external ear canal, tympanic membrane(TM), scutum, tympanum and mastoid were measured and categorized.Results: Fourteen patients showed no or mild destruction in the external ear canal(stage Ⅰ group). Eight patients had obvious enlargement in the external ear canal(stage Ⅱ group) but showed limited destructions of the mastoid bone and no damage of the tympanums. Five patients had serious destruction of the mastoid bone and damage of the tympanum(stage Ⅲ group). All patients in the stage Ⅲ group showed a compression of manubriums and TMs, with 3 having damages on ossicular chain. Bone destruction of the vertical section of facial nerve canal was discovered in one case in the stage Ⅲ group.Conclusion: HRCT can provide detail information about the extent of external ear canal cholesteatoma. Such information can be used to identify special situations with serious complications and to differentiate external ear canal cholesteatoma from middle ear cholesteatoma.