Forward Movement Research Articles

Between Freedom and Order: Evolution logic of urban-rural population mobility Policy from the perspective of historical institutionalism

Urban-rural population flow is the key element and important driving force for urban-rural integration development and rural revitalization. The pattern of urban-rural population flow in China is restricted and guided by policies. From the perspective of historical institutionalism, this paper analyzes the evolution context, structural logic and dynamic mechanism of the change of urban and rural population mobility policy. The urban and rural population mobility policy has gone through five historical stages: the order reconstruction period at the beginning of the founding of New China, the political call period after the Great Leap Forward Movement, the free flow period after the reform and opening up, the period of making the best use of the situation under the economic system reform and the accelerated integration period under the background of the new era. The institutional choice under different paths, the institutional evolution under the key nodes and the institutional continuation under the path dependence constitute the structural logic of the policy change of urban-rural population mobility. The situation coupling under the action of exogenous variables, the value coupling promoted by the change of ideas, and the subject coupling under the interaction of actors’ game constitute the dynamic mechanism of policy change, which promotes the historical change and realistic development of policy.

Amartya Sen's social justice

AbstractThis paper uses lines of argument drawn from Amartya Sen's Idea of Justice to support the notion that NGO efforts, far from being oppressive, are helpful and progressive. It cites the work of Lairap‐Fonderson and Chen, and alludes to specific projects. Contrast is made with Rawls, and the paper suggests that more formal theories of justice may not enable us to grapple with our intuitive sense that justice for the poverty stricken involves, at a minimum, both financial progress and forward movement with respect to internal growth. Examples of work done by NGOs in Bangladesh and other places help us to realize that women in these areas often have their own sense of what a more just situation would require—and NGOs and others can work from these conceptions as a point of departure. Part of the conclusion here is that Sen's concept of the just is a step in the right direction.

PI-Filter compensator for LQG controller aimed to fixed-wings aircrafts

Fixed-wing aircraft use their wings to generate lift and propulsion, relying on forward motion for airflow rather than rotating blades like helicopters. They offer advantages such as extended range, higher speeds, stability in turbulent weather, and lower operational costs compared to rotary-wing aircraft. A study introduces a method to improve control smoothness for fixed-wing aircraft using LQG control and PI filter compensation. Flight simulators like FlightGear are used for testing control algorithms before real-world experiments, offering realistic flight dynamics and versatile options for various aircraft types. This approach provides a cost-effective and efficient way to develop and test controllers for challenging flight scenarios.

Motion Accuracy of Pneumatic Stepper Motor-Driven Robotic System Developed for MRI-Guided High-Intensity Focused Ultrasound Treatment of Prostate Disease

The latest advancement in high-intensity focused ultrasound (HIFU) treatment technology integrates magnetic resonance imaging (MRI) guidance for precise treatment of prostate disease. As conventional electromagnetic motors are not applicable for utilization within MRI scanners, we have developed a prototype robotic system driven by pneumatic stepper motors to control the movement of the HIFU transducer within an intrarectal probe during MRI-guided HIFU treatment procedures. These pneumatic stepper motors were constructed entirely from MRI-compatible plastic materials. Assessment of the robotic system’s MRI compatibility was conducted utilizing a 3.0T MRI scanner, revealing no discernible MRI image distortion with a minor decrease in the signal-to-noise ratio (2.8%) during the motor operation. The robotic system enabled the transducer to move inside the probe with two degrees of freedom, allowing both linear and rotational motion. The positional accuracy of the transducer movement was assessed, yielding ±0.20 and ±0.22 mm accuracies in the forward and backward linear movements, respectively, and ±0.79° and ±0.74° accuracies in the clockwise and counterclockwise rotational motions, respectively. Emulation of authentic HIFU procedures involved creating a two-dimensional array of thermal lesions in a tissue-mimicking phantom, achieving positional accuracy within ±1 mm for the generated HIFU focal spots. The prototype robotic system incorporating pneumatic stepper motors fabricated entirely from MRI-compatible plastic materials has demonstrated the requisite positional accuracy necessary for effective HIFU treatment of prostate disease, indicating substantial promise for future clinical application.

Consistent social information perceived in animated backgrounds improves ensemble perception of facial expressions.

Observers can rapidly extract the mean emotion from a set of faces with remarkable precision, known as ensemble coding. Previous studies have demonstrated that matched physical backgrounds improve the precision of ongoing ensemble tasks. However, it remains unknown whether this facilitation effect still occurs when matched social information is perceived from the backgrounds. In two experiments, participants decided whether the test face in the retrieving phase appeared more disgusted or neutral than the mean emotion of the face set in the encoding phase. Both phases were paired with task-irrelevant animated backgrounds, which included either the forward movement trajectory carrying the "cooperatively chasing" information, or the backward movement trajectory conveying no such chasing information. The backgrounds in the encoding and retrieving phases were either mismatched (i.e., forward and backward replays of the same trajectory), or matched (i.e., two identical forward movement trajectories in Experiment 1, or two different forward movement trajectories in Experiment 2). Participants in both experiments showed higher ensemble precisions and better discrimination sensitivities when backgrounds matched. The findings suggest that consistent social information perceived from memory-related context exerts a context-matching facilitation effect on ensemble coding and, more importantly, this effect is independent of consistent physical information.

Neither “Problem Plays” Nor “Problem Comedies”: Sexuality and Survival in All’s Well that Ends Well, Measure for Measure and Troilus and Cressida

ABSTRACT The paper argues that All’s Well That Ends Well, Measure for Measure and Troilus and Cressida are neither “Problem Comedies” nor “Problem Plays”. They have been viewed in terms of a genre to which they do not quite belong, and the fact that they deal with problems has somehow been construed to mean that they are problems. These plays show continuities with the previous comedies but also mark a forward movement and a further development. Where romantic love is the basis of early comedy, “the urgency of sexuality” is now the major theme and complex issues of sexual desire and its fulfilment are explored. The focus is primarily on women and their vulnerability, women who are insecure, threatened, and discover they can use their sexuality, the very thing that makes them vulnerable, as a weapon, as leverage, to help them survive. These are plays about sexuality, compromise, and survival.

GORDON LYALL PAVER (1913–1988) AND 42ND GEOLOGICAL SECTION, SOUTH AFRICAN ENGINEER CORPS: MILITARY GEOLOGY AND GEOPHYSICS IN WORLD WAR II SUPPORTING BRITISH ARMY OPERATIONS: PART 1, THE EAST AFRICAN CAMPAIGN 1940–1941

ABSTRACT 42nd Geological Section of the South African Engineer Corps was a unique unit that supported British armed forces during World War II. It was co-founded and led for most of the war by Gordon Lyall Paver (1913–1988), one of the few ‘British’ officers serving specifically as geologists during the war to achieve the rank of major. Born in South Africa at Johannesburg and in his early years educated there at St. John's College, from 1926 Paver was educated in England, at Charterhouse School until admitted in 1931 to Pembroke College in the University of Cambridge, where he studied chemistry, geology and mineralogy. He graduated in 1934 and returned to South Africa, being appointed to the Geological Survey of South Africa as one of its first geophysicists and contributing to magnetometric and gravimetric surveys in the Transvaal region, expertise used in 1938 to 1940 to draft his thesis for a PhD degree (awarded in 1942). Although married in 1939 and briefly employed as a consultant geophysicist, in August 1940 Paver was one of the first three geoscientists to be mobilized as officers to found 42nd Geological Section, at Zonderwater near Pretoria in South Africa. After only a month's military training, at the end of September the Section and its vehicles deployed by rail and sea to a base near Nairobi in Kenya for operational service in East Africa, with ‘Acting Captain’ Paver as its Second-in-Command. Detachments from the Section were widely deployed in Kenya and later in Italian and British Somaliland (present-day Somalia) and also in Abyssinia (present-day Ethiopia) for surveys by means primarily of electrical earth resistivity but also vertical force magnetometer. These guided drilling of wells by another unit of the South African Engineer Corps to abstract potable groundwater— thereby facilitating troop concentrations and forward movements in arid or semi-arid regions during the ‘British’ Army's East African Campaign. Members of the Section also compiled geological maps of Kenya at scales of 1:1,000,000 and 1:2,000,000 and pioneered a military geological unit created within the East African Engineers that supported British forces in the region from 1941 to 1945. The Campaign drew to a victorious close during 1941 and, from the end of August, the Section was re-deployed northwards to a base near Cairo in Egypt. It continued to serve within the British Army's Middle East Command but with leadership now by Paver, promoted ‘Acting Major’ from 31 August and in December ‘mentioned in despatches’ for his earlier distinguished service in East Africa.

The Forward Movement: Amplifying Black Voices on Race and Orthopaedics—Elevating the Discussion on Race

The Forward Movement: Amplifying Black Voices on Race and Orthopaedics—Elevating the Discussion on Race

Mechanism of respiratory protective equipment in controlling wearer’s exhaled pollutants

Respiratory protective equipment (RPE) filters and blocks exhaled pollutants to prevent their forward movement, protecting the directly exposed individuals and products. Two mechanisms of RPE in controlling wearer's exhaled pollutants, namely filtering and blocking, were examined. Leakage ratio was firstly proposed to evaluate the relative strength of leakage via gaps and leakage via face mask’s surface. Influence of various factors on the two mechanisms was investigated using validated Computational Fluid Dynamics (CFD) technology. The leakage ratio of 0.1–10 μm particles (i.e., 2–36) is generally larger than that of CO2 (i.e., 0.1–10), suggesting that face masks have a stronger blocking effect on the particles compared to the gaseous pollutants. Decreasing the initial velocity of exhaled air and increasing the diameter of exhaled particles, gap’s area, and viscous resistance of face mask’s surface increase the leakage ratio. When the viscous resistance increases from 4.34 × 106 to 4.34 × 1010, the leakage ratios of CO2 and particles increase by 4 and 23, respectively. When the initial velocity increases from 2.7 to 15 m/s, the leakage ratios of CO2 and particles decrease by 2.5 and 19, respectively. Wearing ordinary face masks alone cannot completely prevent the dispersion of exhaled pollutants, it is recommended to combine face masks with well-designed indoor ventilation to jointly control exhaled pollutants. The obtained data establishes a foundation for understanding the mechanism by which face masks control exhaled pollutants, which assists in the improvement of RPE and the formulation of effective measures to protect individuals and products directly exposed.

Trend change analysis in the assessment of body balance during posture adjustment in reaction to anterior-posterior ground perturbation.

Postural adjustments (PA) occur to counteract predictable perturbations and can be impaired as a result of musculoskeletal and neurological dysfunctions. The most common way to detect PA is through electromyography measurements or center of pressure (COP) position measurements, where analysis in time domain and frequency domain are the most common. Aim of the research was to determine whether a new method of analyzing stabilographic measurements-the COP trend change analysis (TCI) of temporary posture corrections- can expand understanding of changes in balance strategy connected with PA. The study group involved 38 individuals (27women, 11men) aged 23±2.6 years. Measurements were performed using a stabilographic platform placed on a perturbation platform. The tests involved three measurements with forward and backward momentary movements of the platform. Participants were tested in three conditions-knowing the nature, time and direction of perturbation (Tr3), knowing only the nature of perturbation (Tr2) and without any information about the perturbation (Tr1). Statistically significant differences were revealed in the last second of Tr3 for the mean velocity of COP (p<0.05) and for two TCI parameters-TCI_dV (p<0.05) and TCI_dS (p<0.01). The increase in TCI_dV was related to the increase in the mean distance between trend changes (TCI_dS) and constant value of the mean time between trend changes (TCI_dT). The increase of the mean value of TCI_dS was the result of smaller number of posture corrections with the distance 0-2 mm and lager number with the distance 4-6 mm. Obtained results proved that the TCI analysis is a method enabling an extended analysis of PA, indicating the nature of changes occurring in posture corrections-longer momentary jumps of COP-related to a change in the strategy of maintaining balance before a known disorder, which has not been analyzed in this type of research so far.

Study of degenerative (non-lytic) spondylolisthesis grade 1 and 2 in axial MRI images

Background: The traditional imaging assessment of lumbar spondylolisthesis is in sagittal images noting movement of upper body over the lower body. It omits change at the facet. Methods: The present observational, study included 35 patients with degenerative lumbar spondylolisthesis(non-lytic). Radiological analysis of all MRI images was done by 4 independent spinal surgeons and 2 radiologists. The study focused on the axial MRI images and changed relation between the superior articular process and inferior articular process and relation between inferior articular process and canal with thecal sac (traversing root). Results: Majority of DS had sagittal oriented facets (71.43%). In 7 cases at the L3/4 and in 19 cases at L4/5 level both facet joints had sagittal orientation with forward (ventral) movement of IAP. The IAP was found to be encroaching or in close proximity of traversing root. In 1 patient at L3/4 and 6 patients at L4/5 joint was sagittal unilaterally, may be causing compression of the neural elements unilaterally, while on coronal side the IAP and SAP had a normal alignment and not causing neural encroachment Conclusions: We need to concentrate on relation of IAP vs SAP at facet as seen in axial images of facet.

Motor Behavior Regulation of Rat Robots Using Integrated Electrodes Stimulated by Micro-Nervous System.

As a cutting-edge technology, animal robots based on living organisms are being extensively studied, with potential for diverse applications in the fields of neuroscience, national security, and civil rescue. However, it remains a significant challenge to reliably control the animal robots with the objective of protecting their long-term survival, and this has seriously hindered their practical implementation. To address this issue, this work explored the use of a bio-friendly neurostimulation system that includes integrated stimulation electrodes together with a remote wireless stimulation circuit to control the moving behavior of rat robots. The integrated electrodes were implanted simultaneously in four stimulation sites, including the medial forebrain bundle (MFB) and primary somatosensory cortex, barrel field (S1BF). The control system was able to provide flexibility in adjusting the following four stimulation parameters: waveform, amplitude, frequency, and duration time. The optimized parameters facilitated the successful control of the rat's locomotion, including forward movement and left and right turns. After training for a few cycles, the rat robots could be guided along a designated route to complete the given mission in a maze. Moreover, it was found that the rat robots could survive for more than 20 days with the control system implanted. These findings will ensure the sustained and reliable operation of the rat robots, laying a robust foundation for advances in animal robot regulation technology.

Non-Stokesian dynamics of magnetic helical nanoswimmers under confinement.

Electromagnetically propelled helical nanoswimmers offer great potential for nanorobotic applications. Here, the effect of confinement on their propulsion is characterized using lattice-Boltzmann simulations. Two principal mechanisms give rise to their forward motion under confinement: (i) pure swimming and (ii) the thrust created by the differential pressure due to confinement. Under strong confinement, they face greater rotational drag but display a faster propulsion for fixed driving frequency in agreement with experimental findings. This is due to the increased differential pressure created by the boundary walls when they are sufficiently close to each other and the particle. We have proposed two analytical relations (i) for predicting the swimming speed of an unconfined particle as a function of its angular speed and geometrical properties, and (ii) an empirical expression to accurately predict the propulsion speed of a confined swimmer as a function of the degree of confinement and its unconfined swimming speed. At low driving frequencies and degrees of confinement, the systems retain the expected linear behavior consistent with the predictions of the Stokes equation. However, as the driving frequency and/or the degree of confinement increase, their impact on propulsion leads to increasing deviations from the Stokesian regime and emergence of nonlinear behavior.

Leveraging an intensive time series of young children's movement to capture impulsive and inattentive behaviors in a preschool setting.

Studying within-person variability in children's behavior is frequently hindered by challenges collecting repeated observations. This study used wearable accelerometers to collect an intensive time series (2.7 million observations) of young children's movement at school (N = 62, Mage = 4.5 years, 54% male, 74% Non-Hispanic White) in 2021. Machine learning analyses indicated that children's typical forward acceleration was strongly correlated with lower teacher-reported inhibitory control and attention (r = -.69). Using forward movement intensity as a proxy for impulsivity, we partitioned the intensive time series and found that (1) children modulated their behavior across periods of the school day, (2) children's impulsivity increased across the school week, and (3) children with greater impulsivity showed greater variability in behavior across days.

Relationship between the strength of the ankle and toe muscles and functional stability in young, healthy adults.

This study investigates the relationship between ankle and toe strength and functional stability in young adults, with a sample comprising sixteen females and fourteen males. The research employed force platform data to determine the center of foot pressure (COP) and calculated the forward functional stability index (FFSI) through foot anthropometric measurements. Strength measurements of toe and ankle muscles, during maximal isometric flexion and extension, were conducted using force transducers. Notable positive correlations were found between toe flexor strength and FFSI (left flexor: r = 0.4, right flexor: r = 0.38, p < 0.05), not influenced by foot anthropometry. Contrarily, no significant correlation was observed between ankle muscle strength and FFSI, despite a positive correlation with the COP range. The moderate correlation coefficients suggest that while toe flexor strength is a contributing factor to functional stability, it does not solely determine functional stability. These findings highlight the critical role of muscle strength in maintaining functional stability, particularly during forward movements and emphasize the utility of FFSI alongside traditional COP measures in balance assessment. It is recommended to employ a multifaceted approach is required in balance training programs.

Model predictive path-following control for truck–trailer systems with specific guidance points — design and experimental validation

This article presents an experimental validation of a model predictive path-following control algorithm (PF-MPC ) applied to a truck–trailer system, encompassing both forward and backward motions. The proposed controller is designed to precisely follow a predefined path generated by a path planner, with a designated guidance point positioned on either the truck or the trailer. The algorithm’s performance is assessed through implementation and validation on a model-scaled truck–trailer system, where MPC, state estimation, and low-level control are executed on a microcontroller (MCU ). The experimental results demonstrate the effectiveness of the proposed control approach in achieving highly accurate path-following performance, even when operating in the challenging context of unstable backward motion, and with the involvement of up to two trailers. Moreover, the successful implementation of the algorithm on a microcontroller underscores its suitability for real-time control applications. The results of this study collectively highlight the promising potential of the proposed control algorithm for practical utilization in autonomous driving systems.

The Effect of Heat Treatment and Build Orientation on the Susceptibility of Laser Powder Bed Fusion Additively Manufactured Alloy 625 to Crevice Corrosion

This study aimed to determine the optimal heat treatment and build orientation to minimize the susceptibility of additively manufactured (AM) Alloy 625 to crevice corrosion. To accomplish this, metal-to-metal and acrylic-to-metal remote crevice assembly (RCA) experiments were performed for as-made (NT) AM, stress-relieved (SR) AM, solution-annealed AM, and solution plus stabilization-annealed AM Alloy 625 in two different build orientations. Current vs. time data from metal-to-metal RCA experiments were analyzed using commercially available statistical analysis software used to perform analysis of variance. While there was a lack of statistical evidence that build orientation affects crevice corrosion susceptibility, there was strong evidence heat treatment affects crevice corrosion susceptibility. Specifically, according to Tukey’s Multiple Comparison, alloys that were heat treated had a statistically significant lower charge passed as compared to the NT specimens. This finding was consistent with measured penetration depth where NT AM specimens had the largest maximum penetration depth. In contrast, acrylic-to-metal RCAs were used to calculate crevice corrosion current density (rate) and repassivation potential. While current densities for the AM materials were comparable, the forward motion of the active crevice corrosion front on the NT and SR specimens was found to be slow, resulting in high damage accumulation locally. Both metal-to-metal and acrylic-to-metal RCA results are discussed within the context of nonhomogenized microstructures associated with AM.

Modeling single cell trajectory using forward-backward stochastic differential equations.

Recent advances in single-cell sequencing technology have provided opportunities for mathematical modeling of dynamic developmental processes at the single-cell level, such as inferring developmental trajectories. Optimal transport has emerged as a promising theoretical framework for this task by computing pairings between cells from different time points. However, optimal transport methods have limitations in capturing nonlinear trajectories, as they are static and can only infer linear paths between endpoints. In contrast, stochastic differential equations (SDEs) offer a dynamic and flexible approach that can model non-linear trajectories, including the shape of the path. Nevertheless, existing SDE methods often rely on numerical approximations that can lead to inaccurate inferences, deviating from true trajectories. To address this challenge, we propose a novel approach combining forward-backward stochastic differential equations (FBSDE) with a refined approximation procedure. Our FBSDE model integrates the forward and backward movements of two SDEs in time, aiming to capture the underlying dynamics of single-cell developmental trajectories. Through comprehensive benchmarking on multiple scRNA-seq datasets, we demonstrate the superior performance of FBSDE compared to other methods, highlighting its efficacy in accurately inferring developmental trajectories.

Research and Manufacture of Hydraulic Butt Fusion Welding Machine for Different Plastic Material Pipes

This paper introduces the research and manufacture of a hydraulic butt fusion welding machine that permits to weld dissimilar plastic pipes. In welding of dissimilar plastic pipes, the welding parameters at two pipe ends will be different. The butt fusion welding cycle of two dissimilar plastic pipes is established. The fabricated welding machine consists of the following basic components: machine body, two heating plates, four movable clamp rings, hydraulic movement mechanism to move the heater plate, hydraulic system to control the pressure and also to move the pipe ends during welding process. The pressed system has four movable cylinder tubes that move on four fixed pistons. At each side (left and right), a pair of two clamp rings is mounted on two movable cylinder tubes to provide forward and backward movement of a pipe during welding process. Two heater plates heat the two plastic pipe ends at different temperatures depending on the welding temperature of each plastic pipe material. The welding process is built in order to weld two dissimilar plastic pipes. The fabricated hydraulic butt fusion welding machine and the established welding process ensure accuracy and quality for the welding joint of dissimilar plastic pipes.

A tonically active master neuron modulates mutually exclusive motor states at two timescales.

Continuity of behaviors requires animals to make smooth transitions between mutually exclusive behavioral states. Neural principles that govern these transitions are not well understood. Caenorhabditis elegans spontaneously switch between two opposite motor states, forward and backward movement, a phenomenon thought to reflect the reciprocal inhibition between interneurons AVB and AVA. Here, we report that spontaneous locomotion and their corresponding motor circuits are not separately controlled. AVA and AVB are neither functionally equivalent nor strictly reciprocally inhibitory. AVA, but not AVB, maintains a depolarized membrane potential. While AVA phasically inhibits the forward promoting interneuron AVB at a fast timescale, it maintains a tonic, extrasynaptic excitation on AVB over the longer timescale. We propose that AVA, with tonic and phasic activity of opposite polarities on different timescales, acts as a master neuron to break the symmetry between the underlying forward and backward motor circuits. This master neuron model offers a parsimonious solution for sustained locomotion consisted of mutually exclusive motor states.