Vertical Control Research Articles

Multi-Physics Ensemble Framework for Representing Western Himalayan Precipitation Climatology and Extremes: An Assessment from WRF Model

Abstract Numerical model simulations are sensitive to the choice of physical parameterizations, particularly those related to convection processes, especially over complex terrains like the western Himalayan region. This study evaluates the sensitivity of the Weather Research and Forecasting model to three convective parameterization schemes (BMJ, Betts–Miller–Janjić; KF, Kain–Fritsch; GF, Grell–Freitas) and their multi-physics ensemble mean (ENSM) through long-term (2001-2016) winter (December-March) simulations. Model outputs are validated against multi-source datasets (IMD, IMERG, ERA5, and IMDAA), with extreme precipitation events (EPEs) identified as those exceeding the 95th percentile threshold. Climatology analysis reveals systematic precipitation biases across all single schemes, significantly reduced in the ENSM. Improvements in skill scores observed for ENSM highlight the reliability of ensemble approach as an alternative to account for model errors. Underestimations of low-level clouds and hydrometeors improve in ENSM. BMJ and KF (GF) schemes exhibit overestimated (underestimated) magnitudes and location-wise discrepancies for baroclinic instability and moisture transport. These issues are mitigated in ENSM, resulting in better alignment with reference datasets. Additionally, ENSM and KF’s storm tracks align well with reanalyses, while individual schemes show a minor northward placement. For EPEs, ENSM highlights Jammu-Kashmir, Himachal, and Uttarakhand as zones of maximum heavy precipitation and frequency. ENSM realistically represents the western disturbance (WD) induced circulation characteristics, southward-displaced subtropical jet, shifts in WD-associated vorticity maxima, and potential vorticity intrusions during extremes. Consistent with reference datasets, ENSM demonstrates the crucial role of vertical advection and dynamical controls in moisture distribution during EPEs. Our analysis indicates that a suitable WRF cumulus configuration includes either the multi-physics ENSM or the KF scheme, while the GF scheme yields the poorest results. The findings underscore the importance of evaluating both precipitation characteristics and underlying physical mechanisms to identify sources of systematic biases in model simulations.

Research on nonlinear dynamic vertical vibration characteristics and control of roll system in cold rolling mill

In order to address the vertical vibration phenomenon of the working roll during the rolling process, taking into consideration the nonlinear factors of the rolling interface and the roll system, this study establishes a nonlinear excitation vertical vibration model based on dynamic rolling force. The impact of nonlinear factors on system stability and vibration characteristics is analyzed. The study reveals that nonlinear damping and linear stiffness exhibit significant effects through time delay characteristics. Nonlinear stiffness has a drastic impact on system stability, while increasing system damping effectively reduces the amplitude and narrows the resonance region. By employing averaging method and singular value theory, the stability of the cold rolling mill roll system is analyzed under non-autonomous and autonomous states. A combined time-delay feedback controller is proposed, which effectively suppresses the system’s large-scale vibration by adjusting the control gain and time delay parameters. MATLAB simulations are conducted to validate the accuracy of the control strategy, providing theoretical support for vibration prediction and system design in rolling mills.

Optimal design and numerical studies of negative stiffness device–TMD controlled systems using PSO algorithm

In recent years, research on negative stiffness devices (NSDs) for vibration control has increased. This study examines the combination of NSDs with tuned mass dampers (TMDs) and explores the NSD-TMD as a nonlinear energy sink (NES). The particle swarm optimization (PSO) algorithm was employed to determine the optimal parameters for the TMD, NSD-TMD, and NES systems. The optimization procedure proves that the PSO algorithm is suitable for solving the optimization problem of the complex systems with strong nonlinearity. The overall procedure is effective and demonstrates strong convergence. The force transmissibility curves of the optimized systems were compared, revealing that the NSD-TMD achieved the best vibration performance, while the NES system demonstrated the target energy transfer (TET) property. Another interesting characteristic of the NSD-TMD system is that it does not necessarily require a large additional mass or damping factor to achieve optimal performance. An actual vertical vibration control scenario for a pedestrian bridge was analyzed using various control strategies. Human-induced force excitations were simulated using a code-defined method. The acceleration responses of an uncontrolled pedestrian bridge and the three optimized control systems were compared in both time and frequency domains. Results further verified the force transmissibility curves. The NSD-TMD system outperformed the other two systems, particularly in reducing the first-order response. Conversely, the NES system proved less effective for controlling human-induced vibration with harmonic force excitations.

Whistleblowing intensity and distributor compliance in marketing channel networks

PurposeThis paper aims to examine how channel whistleblowing intensity affects a distributor’s compliance to the manufacturer’s request and how that impact is influenced by institutional environments.Design/methodology/approachBased on paired survey data, which was collected from an automobile manufacturer in China and its 211 distributors, combined with secondary data, this study used hierarchical regression analyses to test the hypotheses.FindingsThe study finds that channel whistleblowing intensity has an inverted U-shaped effect on distributor compliance. In addition, this curvilinear effect is stronger in regions with more effective legal systems and higher social trust, but the authors do not find perceived vertical control moderating the effect of whistleblowing intensity on distributor compliance.Research limitations/implicationsFirst, this study enriches the marketing literature by highlighting the significance of whistleblowing and especially its downside in marketing channel management. Second, moving beyond prior marketing studies’ focus on bilateral controls, it recognizes channel whistleblowing as a peer-enforced control mechanism. Third, it identifies environmental factors as shift parameters that alter the impact of channel whistleblowing, attesting to the importance of “discriminating alignment.”Practical implicationsThe findings caution channel managers against the double-edged effects of whistleblowing and inform the conditions that amplify this impact.Originality/valueThis work highlights the bright and dark sides of channel whistleblowing and uncovers situations in which it works or fails to promote distributor compliance.

Analysis of the Vertical Dynamic Response of SDCM Piles in Coastal Areas

The stiffened deep cement mixing (SDCM) pile, as a new type of rigid–flexible composite pile, significantly enhances the vertical bearing capacity of traditional precast piles, thus holding broad application prospects in the substructure construction of nearshore bridges and marine energy structures. This paper investigates the vertical dynamic response of SDCM piles through theoretical derivation and parameter analysis. Firstly, based on elastic dynamics theory and the three-phase porous media model, vertical vibration control equations for both SDCM piles and fractional-order viscoelastic unsaturated soils are established. Secondly, theoretical derivations yield exact analytical solutions for the surrounding dynamic impedance, top dynamic stiffness, and dynamic damping of the SDCM pile. Finally, through numerical examples and parameter studies, the impact mechanisms of physical parameters in the SDCM pile–unsaturated soil dynamic coupling system on the top dynamic stiffness and dynamic damping of the SDCM pile are analyzed. The research results presented in this paper indicate that reducing the radius of the rigid core pile while increasing the thickness of the exterior pile has a positive effect on enhancing its vibration resistance. Additionally, increasing the length of SDCM piles contributes to improved vibration performance. However, an increase in the elastic modulus of the cement–soil exterior pile is detrimental to the vibration resistance of the rigid composite pile. On the other hand, an increase in the elastic modulus of the concrete core pile only enhances its ability to resist vibration under low-frequency load excitation. Furthermore, enlarging the soil saturation, decreasing the intrinsic permeability, and enlarging the soil relaxation shear modulus have a significant positive impact on improving the vibration resistance of SDCM piles. In contrast, changes in porosity have a negligible effect on the ability to resist vertical vibrations of SDCM piles.

Briefing: Vertical vibration control of over-track buildings: information for practitioners

In recent decades, transit-oriented development has emerged as a prominent trend in metropolises. Modern infrastructures and residential buildings are strategically constructed above subway lines or parking depots, facilitating convenient access to city transportation. Nevertheless, complaints regarding the vibrations induced by metro vehicles have been on the rise.

Vertical Dimension Control in Two Different Treatment Protocols: Invisalign First and Bite Block-A Retrospective Study.

The aim of the present study was to compare the vertical dimension changes, before and after treatment, in two groups of growing patients, one group treated with clear aligner therapy versus a group treated with Quad-helix and bite-block therapy. The studied sample was composed of n. 40 patients (20 females and 20 males with a mean age of 8.6 ± 1.8 years), enrolled from the Department of Orthodontics at Policlinico of Rome Tor Vergata. The original sample was randomly divided into two groups: Group IF (Invisalign First) and Group BB (Quad-helix and bite block). Pre- (T0) and post-treatment (T1 after 12 months) lateral cephalograms were collected from all the selected patients. Nine cephalometric parameters, both angular and linear, were measured and recorded for each cephalogram. No statistically significant changes were found between both the IF and BB groups at T0, while statistically significant changes were observed in both groups (BB and IF) between T0 and T1 (after 12 months of active therapy), p < 0.005. Both therapies were able to control the patient's vertical condition. To date, the use of conventional appliances seems to have slightly better efficacy in controlling the vertical dimension than aligner therapy.

Theoretical and experimental investigation of flexible air spring stiffness in a tuned liquid column gas damper for vertical vibration control

This study investigates the effectiveness of equivalent linear air spring stiffness in a Vertical Tuned Liquid Column Gas Damper (VTLCGD) for reducing vertical structural vibrations, particularly considering different sealing conditions. The VTLCGD system, designed with a single sealed vertical air column, allows flexible frequency tuning by adjusting the air spring stiffness. It aims to be used in low-frequency structures where conventional VTLCGD designs with two sealed ends are less efficient. The geometric configuration and working principle of the VTLCGD are first described. The equation of motion is derived using liquid dynamic equilibrium and the pressure-volume relationship, with expressions for natural frequency and control force validated through shaking table tests conducted with varying VTLCGD lengths. Experimental investigations are conducted to examine the parameters affecting damper performance using pressure data. The system's vibration reduction performance is then numerically evaluated on a cantilevered floor subjected to human walking. The numerical results, based on the equation of motion for liquid displacement and natural frequency, show good agreement with experimental data, which confirms the effectiveness of using linearized air spring stiffness for frequency tuning. The effects of total liquid length and height difference on control force are further investigated, and a polytropic index of 1.2 is determined for the VTLCGD frequency formula. The VTLCGD system achieves a maximum vibration reduction of 52.63 % in acceleration response on the cantilevered floor compared to the uncontrolled case. Moreover, the variation in stiffness due to changes in the sealing condition is presented to validate the damper's adaptability over a wide frequency range.

Incremental robust predictive control for anti-pitching in catamarans with appendage constraints

To solve the problem that high-speed catamarans have excessive amplitude of vertical motion in rough sea conditions, an anti-pitching method based on incremental robust predictive control of catamarans is proposed, which takes into account the model uncertainty and input rate of appendage requirements. Thus, a high-speed catamaran vertical control model is established with T-foils and flaps serving as anti-pitching appendages, and the hydrodynamic coefficient uncertainties is analyzed, which is converted into a state space model with norm-bounded uncertainty to facilitate control system design; moreover, transforming the norm-bounded uncertainty model of a high-speed catamaran into an incremental model, which can increase the integral action to improve the anti-pitching performance. On this basis, the hybrid H2/H∞ robust predictive control method is proposed to achieve wave disturbance resistance capability and robust stability of the catamaran system, taking the rate of input of the anti-pitching appendages as the input constraints, and the linear matrix inequality (LMI) receding-horizon optimization is used to solve the incremental control input of appendages. Ultimately, the effectiveness of the proposed algorithm is verified by digital simulation.

Application of 3D Geological Modeling Technology for Single Sand Body in Block S

Abstract The P oil layer is generally in a medium to high water cut period, with scattered macroscopic residual oil distribution. The reserves are mainly distributed in the microfacies of river sand bodies, and the main layer is severely flooded with water, resulting in ineffective circulation in some areas. Therefore, it is necessary to tackle the modeling technology within the layer and describe the remaining oil within the layer to meet the needs of tapping the potential of remaining oil during the high water cut period. This article takes the establishment of a three-dimensional geological model of a single sand body within the S block layer as an example. Based on the establishment of a fine structural model, the “plane and vertical dual control” modeling method is used. The implementation method is: controlling the range of sedimentary facies maps → using the top surface of the sand body as the top depth of the river channel → controlling the vertical shape of the river channel through the facies controlled sandstone contour map, thereby achieving the vertical shape of the river channel through the facies controlled sandstone contour map, and establishing a three-dimensional sedimentary facies model of a single sand body. Optimize the method for characterizing interlayers, achieve modeling of single sand body interlayers, and perform random simulation interpolation in phases to obtain attribute models. The use of a single sand body model within a layer can visually display the three-dimensional channel morphology and classify the identified connected bodies within the study area. The upscaling method of sedimentary facies models with irregular boundaries greatly reduces the number of model grids and provides a relatively refined geological model for numerical simulation.

Key Technologies for Volume Fracturing of Yingxiongling Shale Oil in the Qaidam Basi

Abstract The Yingxiongling shale oil in the Qaidam Basin is the preferred choice for Qinghai Oilfield to enter the field of unconventional oil and gas resources, and volume fracturing is the core technology for shale oil exploration and development. Through the analysis of the geological and engineering characteristics of the Yingxiongling shale oil, it is found that there are difficulties in volume fracturing of the Yingxiongling shale oil, such as frequent changes in vertical mechanical properties and limited vertical control range; large stress differences, making it difficult to form complex artificial fractures; difficulty in opening multiple clusters of perforation holes; high water shortage in the plateau, high mineralization of the formation backflow fluid, and difficulty in reusing the backflow fluid. By iteratively modeling three-dimensional geomechanics, a high-resolution three-dimensional geomechanical model is established to guide the optimization of volume fracturing schemes. Through the integration of geological and engineering selection and clustering, three-stage active control technology for cracks, and the dual temporary plugging process of boreholes and cracks, the targeted and complex degree of artificial crack transformation can be improved. Through the study of high salinity fracturing fluid system, it has been found that high salinity backflow fluid can replace slick water and alleviate the demand for fresh water in volume fracturing. The article analyzes the difficulties of shale oil volume fracturing and studies the formation of an effective set of key techniques for volume fracturing, achieving the goal of improving the degree and effectiveness of transformation, and providing support for the exploration and development of the Yingxiongling shale oil in the Qaidam Basin.

Incremental Sliding Mode Control for Predefined-Time Stability of a Fixed-Wing Electric Vertical Takeoff and Landing Vehicle Attitude Control System

Incremental Sliding Mode Control for Predefined-Time Stability of a Fixed-Wing Electric Vertical Takeoff and Landing Vehicle Attitude Control System

Congenital transmission of Chagas disease: The role of newborn therapy on the disease’s dynamics

Chagas disease, also known as American trypanosomiasis, is caused by a protozoan blood-borne pathogen called Trypanosoma cruzi. The World Health Organization (WHO) has classified Chagas as one of 21 neglected tropical diseases present in the world and estimates that 6-7 million people are currently infected with Chagas. Congenital transmission of Chagas disease contributes to a significant amount of new infections, especially in endemic areas where 22.5% of new infections are due to congenital transmission. In this paper, we investigate congenital transmission’s impact on Chagas disease dynamics through a mathematical model. Specifically, we examine how treating a proportion of infants born to infected individuals impacts the progression and spread of Chagas disease. The influence of newborn therapy on the dynamics of the model is thoroughly investigated, both theoretically and numerically. The results illustrate the importance of treating a high proportion of newborns to reduce the number of infected cases of the disease. The findings show that the therapy given to newborns is necessary but not sufficient to curb the transmission of Chagas disease, and a comprehensive approach that includes vector and vertical transmission control strategies is essential for eradicating Chagas disease. We also observed that if vector transmission can be controlled, then at least 55% of the newborns need to be treated to eliminate the disease.

Comparison of the Effects of Different Palatal Morphology on Maxillary Expansion via RME and MSE: A Finite Element Analysis.

This study aims to compare and analyze the biomechanical effect and the displacement trend of RME and MSE on the maxillofacial complex under different palatal shapes by using finite element analysis. The three-dimensional model of maxillofacial complex was obtained from a computed tomography image of a person with a normal palate. Then, we modified the shape of the palate to obtain the model with a high palate. Additionally, two expander devices were considered. MSE and RME were created and four models were made: Model 1: Normal-palate craniomaxillofacial complex with RME expander; Model 2: Normal-palate craniomaxillofacial complex with MSE expander; Model 3: High-palate craniomaxillofacial complex with RME expander; Model 4: High-palate craniomaxillofacial complex with MSE expander. Then, lateral forced displacement was applied and the analysis results were obtained. The lateral displacement of the palatal suture of Model 3 is greater than that of Model 1, and the maxilla has more rotation. The crown/root ratio of Model 1 is significantly greater than that of the other three groups. Compared with Model 1, Model 3 has greater stress concentration in the superstructure of the craniomaxillofacial complex. Both of them have greater stress in the anchorage area than Model 2 and Model 4. Different shapes of the palate interfere with the effects of RME and MSE, and its influence on the stress distribution and displacement of the craniomaxillary complex when using RME is greater than MSE. The lateral displacement of the palatal suture of MSE is significantly larger than that of RME. It is more prone to tipping movement of the anchor teeth using RME under normal palate, and MSE may manage the vertical control better due to the smaller crown/root ratio than RME and intrusive movement of molars.

Measurement and analysis of vibration responses due to subway transit in residential areas

The issue of building vibrations caused by subway operations has become increasingly prominent, significantly impacting residents' daily lives. This study investigates the vibration response of a residential area when the subway passing through, which involved the vibrations of the free field, the basement, and the nearby buildings. In addition, numerical simulation of building vibration by Etabs software was discussed. The free field vibration above the shield tunnel diminishes rapidly in the vertical track direction as the horizontal distance increases. However, the influence range of subway induced vibrations significantly expands when a basement is built adjacent to the subway. Data on building vibrations revealed the distribution of vibrations along the vertical direction and the vertical vibration amplification at the slab center due to local resonance. Interestingly, isolation designed for seismic loads also offers some benefits in reducing vertical vibrations. The numerical simulation results of the vibration response at the shear wall bottom show a certain degree of consistency with the actual measured results, but the attenuation of the vibration is faster, which may underestimate the vibration response of the building. The findings of this study provide valuable insights for understanding the impact of subway operations on surrounding buildings, optimizing subway and structural spatial layouts, and designing for vertical vibration control.

Vertical instability forecasting and controllability assessment of multi-device tokamak plasmas in DECAF with data-driven optimization

Vertical instability forecasting and controllability assessment of multi-device tokamak plasmas in DECAF with data-driven optimization

Research on dynamic constraint mechanism and motion control of intelligent vehicles based on preview distance optimization under complex road conditions

Aiming at the coupling and conflict issues between intelligent vehicle dynamics characteristics and path tracking system under complex road conditions, this paper investigates the dynamics constraint mechanism and motion control of intelligent vehicles, and proposes an intelligent vehicle lateral–vertical cooperative control method based on optimized preview distance. To begin with, an intelligent vehicle path tracking control system based on expected yaw velocity has been designed by establishing a three-degree-of-freedom dynamic model for intelligent vehicle. Then, we analyzed the mechanism by which changes in vehicle speed, road curvature, and preview distance affect the accuracy of vehicle path tracking and handling stability. Considering the “human-vehicle-road” system in intelligent transportation systems, critical values for collision and instability were set. Furthermore, we designed a proactive optimization method for preview distance under different working conditions, using an optimization algorithm to improve path tracking accuracy while ensuring vehicle stability, based on the lateral displacement deviation and lateral orientation deviation representing the accuracy of path tracking, as well as the lateral acceleration representing handling stability. Finally, hardware-in-the-loop platform test was conducted. The simulation and test results show that the optimized path tracking algorithm reduces lateral deviation to as low as 0.05 m, and the stability constraint control in the algorithm can be triggered promptly even under extreme conditions.

Orthodontic re-treatment of class II malocclusion – Strategies for correction of anchorage loss

Orthodontic re-treatment may be required in cases of sub-optimal treatment outcomes. These outcomes may often be due to appliance-driven treatment plan, inadequate bio-mechanical considerations during treatment or poor operator skills. Common issues include anchorage loss, deepening of bite, incorrect extraction protocols, re-opened extraction spaces and loss of vertical control. To address these problems, traditional orthodontic appliances, skeletal anchorage systems, customized appliances, and clear aligners may offer a ray of hope, provided they are used judiciously. To effectively manage re-treatment techniques, it's important to have a solid understanding of the anatomic limits, biomechanics, and potential side effects. Proper case selection is extremely crucial for overall clinical success in such complex situations. Therefore, establishing guidelines and understanding the biomechanical perspectives of various appliance systems are essential to address these challenges in modern orthodontic practice.

Active vertical control with skeletal anchorage for optimizing facial profile in a severe Class II high-angle protrusion case.

This case report describes the nonsurgical management of a patient with a Class II skeletal pattern, retrognathic mandible, steep mandibular angle, maxillary vertical excess, and lip incompetence. The treatment approach involved orthodontic mechanics supported with skeletal anchorage to achieve maximal intrusion and retraction of the dentition. A novel elastic hanging rack appliance, supported by midpalatal miniscrews, was used. A maximal anchorage setup for active vertical control on both arches was illustrated. Significant improvement in the facial profile was achieved with optimal occlusion. Cephalometric analysis revealed successful incisor retraction and intrusion, as well as a forward rotation of the mandible. The treatment outcome illustrates the impact of active vertical control on orthodontic camouflage treatment for severe protrusion.

Evolving Preston’s Equation in Chemical Mechanical Planarization

The evolution of semiconductor devices necessitates greater control parameters for enhancing CMP process controllability. Historically, CMP engineers have sought to improve polishing process performance by real-time control of time, pressure, and velocity using Preston’s equation. However, Preston’s equation has traditionally addressed blanket-wafer or non-patterned wafer’s vertical or horizontal scale controllability, such as wafer center to edge or the in-wafer non-uniformity expressed by percentage. However, limited control variables cannot determine patterning profile changes.Upon closer examination of the basic Preston’s equation, other factors were considered constant or environmental parameters, excluding pressure and velocity. Current and future scaled-down devices demand additional control parameters to achieve nanometer-scale vertical controllability with patterned wafers. This presentation introduces an extended Preston’s equation by incorporating more control parameters, including temperature and slurry concentration. The study reveals that lowering and controlling the polishing temperature induces slurry selectivity changes by modulating the activation energy between the slurry and wafer. This temperature control also drives pad material changes that impact selectivity. Furthermore, the study evaluates in-situ slurry composition control to assess its real-time impact on wafer performance. When all five active parameters are combined into the extended Preston’s equation, it is demonstrated that real-time nanometer vertical scaling is achievable. The results of this study provide insights into the future design direction of CMP equipment, which will be communicated in this talk along with the concept of future CMP equipment.