Jumping Pattern Research Articles

Observer‐Based Switching‐Like Adaptive‐Triggered Resilient Coordination Control of Discrete Singular Systems Under DI Attacks with Uncertain Occurrence Probabilities

ABSTRACTIn this paper, we investigate observer‐based switching‐like adaptive‐triggered resilient state feedback control for discrete singular systems under deception‐injection (DI) attacks. Considering state variables are not completely measurable, a delayed state observer is engineered to reconstruct system states and the occurrence of DI attacks is described by Bernoulli random variables. The upper bound method is used to deal with the DI attacks with jumping patterns and imprecise occurrence probabilities. Taking into account the sporadic nature of DI attacks, switching‐like adaptive‐triggered resilient control method is presented, and the collaboratively designed triggered mechanism and resilient control strategy can not only automatically adjust data transmission based on the system states, but also save communication resources and network bandwidth, and enhance the tolerance to hostile attacks so as to improve safety and reliability of networked singular systems. By utilizing singular value decomposition technique, the noncausal behavior of the singular system is avoided and by applying linear matrix inequality (LMI) technology, the desired gains of controller and observer are achieved concurrently, then neoteric conditions about stochastic admissibility of closed‐loop discrete singular systems are provided. Ultimately, the validity of the proposed resilient coordination control approach is verified via a direct current (DC) motor model.

Diffusion and magnetization of metal adatoms on single-layer molybdenum disulfide at elevated temperatures

The present work models temperature-dependent (500−1300K) diffusion dynamics of Ag, Au, and Cu adatoms on MoS2 as well as electronic and magnetic properties of adatom (Ag, Au, and Cu)/MoS2 systems. Modeling is done by means of ab initio molecular dynamics (AIMD) simulations that account for van der Waals corrections and electronic spin degrees of freedom in the framework of density functional theory. It is found that Ag and Au adatoms exhibit super-diffusive motion on MoS2 at all temperatures, while Cu adatoms follow a random walk pattern of uncorrelated surface jumps. The observed behavior is consistent with AIMD-calculated effective migration barriers Ea (EaAg=190±50meV, EaAu=67±7meV, and EaCu=300±100meV) and can be understood on the basis of the considerably flatter potential energy landscapes encountered by Ag and Au adatoms on the MoS2 surface (corrugation of the order of tens of meV), as compared to Cu adatoms (corrugation >100meV). Moreover, evaluation of the electronic and magnetic properties of AIMD configurations suggest that Ag, Au, and Cu monomer adsorption induces semimetallic features in at least one spin channel of the adatom/MoS2 electronic structure at elevated temperatures. The overall results presented herein may provide insights into fabricating 2D-material-based heterostructure devices beyond graphene.

Consistent pricing of VIX options with the Hawkes jump-diffusion model

This paper presents a valuation of VIX options employing a Hawkes jump-diffusion model that captures the clustering pattern of jumps observed extensively in the financial markets. In the consistent framework, the valuation problem of VIX options is solved efficiently via the Fourier cosine expansion (COS) method. The Monte Carlo (MC) simulations are carried out to demonstrate the reliability and efficiency of the COS method. Furthermore, a sensitivity analysis is performed to show how option prices response to different parameters associated with jump clustering. Finally, empirical studies are conducted to provide evidence to support our jump specification in matching the VIX option surface.

Delineating the anuran axial skeleton.

The axial skeleton of the anurans has undergone an evolutionary reduction of its bone elements. This structural plan is strongly preserved throughout the order and would have emerged as a highly specialized anatomical adaptation to its locomotor jumping pattern. The development programs that direct the vertebral morphogenesis of the anurans are poorly described and the molecular bases that have caused their pattern to differ from other tetrapods are completely unknown. In this work, we review the ontogeny of the spinal column of the anurans and explore the genetic mechanisms that could explain the morphological difference and the maintenance of the body plan during evolution. Here, we propose that the absence of caudal osseous elements, as a consequence of the inability of sclerotomes to form cartilaginous condensations in frogs, could be due to changes in both pattern and expression levels of Hox, Pax1, Pax9 and Uncx4.1 genes along the anteroposterior axis. The anteriorised expression of the Hox genes together with the reduction in the expression levels of Pax1, Pax9 and Uncx4 in the posterior somites could explain, at least partly, the loss of caudal vertebrae in the anurans during evolution.

Youth motor competence promotion model: a quantitative investigation into modifiable factors

ObjectivesThis study aimed to quantify the relationships between enabling, predisposing and reinforcing ecological factors on motor competence and investigate potential sex, weight status, and school level differences. MethodsData were collected from 429 children (52% boys; aged 11.1±0.6 years; 87% white British). Cardiorespiratory fitness (20m Multistage Shuttle Run), muscular strength (Handgrip Strength) and online questionnaire (Child Health and Activity Tool; CHAT) data on moderate-to-vigorous physical activity, sport participation and available surrounding physical activity facilities were included as enabling variables. Three predisposing variables were determined from self-report data on benefits/barriers to exercise, adequacy, and predilection. Parental/guardian physical activity levels and persons whom participate in physical activity and sport with the participant (CHAT) were selected as reinforcing variables. Motor competence was determined from cumulative scores for Dragon Challenge tasks (Balance Bench, Core Agility, Wobble Spot, Overarm Throw, Basketball Dribble, Catch, Jumping Patterns, T-Agility, Sprint). Confirmatory Factor Analysis assessed the fit of measured variables into latent factors. Structural equation modelling evaluated relationships between these latent factors. ResultsMotor competence was directly affected by the enabling factor (β=0.50,p<0.001) but indirectly affected by reinforcing and predisposing factors, mediated by the enabling factor (β=0.13, p=0.014; β=0.25, p=0.002). Multi-group comparisons showed that each of these effects did not differ by sex, weight status or school level (p>0.05). ConclusionsThis study demonstrated that enabling factors are crucial for the development of motor competence. This is the first study to quantify an ecological model with motor competence as the endogenous variable and is key to future interventions.

Development of vertical and forward jumping skills in typically developing children in the context of referent control of motor actions.

The empirically based referent control theory of motor actions provides a new framework for understanding locomotor maturation. Mature movement patterns of referent control are characterized by periods of minimization of activity across multiple muscles (global electromyographic [EMG] minima) resulting from transient matching between actual and referent body configurations. We identified whether locomotor maturation in young children was associated with (a) development of referent control and (b) children's frequency of participation in everyday activities evaluated by parents. Kinematics and EMG activity were recorded from typically developing children (n=15, 3-5years) and young adults (n=10, 18-25years) while walking, vertical or forward jumping. Presence and location of global EMG minima in movement cycles, slopes of ankle vertical/sagittal displacements, and shoulder displacement ratios were evaluated. Children had fewer global EMG minima compared to adults during specific phases of vertical and forward jumps. Ankle displacement profiles for walking and jumping forward were related to each other in adults, whereas those for walking and vertical jumping were related in children. Higher frequency of participation was significantly correlated with more mature jumping patterns in children. A decrease in the number of global EMG minima and changes in ankle movement patterns could be indicators of locomotor immaturity in typically developing children.

Kinematic and Kinetic Analyses of the Vertical Jump with and without Header as Performed by Para-Footballers with Cerebral Palsy.

Vertical jump is a relevant variable in the classification of football for individuals with cerebral palsy. In this regard, the literature is limited. There are no studies assessing vertical jumping ability through kinematic methods and in more specific football game situations, such as jumps with a header. The goals of the present study were to assess how the modification of jumping conditions (without and with a header) might affect the kinematic and kinetic parameters of counter movement jumping, and whether the functional profiles of the players constrain their ability to jump vertically, both with and without a header. Thirteen male football players with cerebral palsy (27.7 ± 5.7 years old) and different functional profiles participated in this study. All the players performed ten counter movement jumps with arms swing, five headed a ball and five did not. The kinematic parameters were recorded with a 3D motion analysis system, and the kinetic parameters using a force platform. Significantly smaller angles of the hips (dg = 0.75–0.79; p < 0.01) and knees (dg = 1.04–1.15; p < 0.05), as well as greater ankle extension (dg = −0.71; p < 0.05), were observed during the eccentric phase of the jumps with a header. There were also asymmetries between legs in ankle extension during jumps with a header (dg = −1.06; p < 0.05), which could be an adjustment element for the precision of the jumps (i.e., header action). It should be mentioned that the jumping pattern could be partially affected by the functional profile of football players with cerebral palsy.

Motion Planning for Bipedal Robot to Perform Jump Maneuver

The remarkable ability of humans to perform jump maneuvers greatly contributes to the improvements of the obstacle negotiation ability of humans. The paper proposes a jumping control scheme for a bipedal robot to perform a high jump. The half-body of the robot is modeled as three planar links and the motion during the launching phase is taken into account. A geometrically simple motion was first conducted through which the gear reduction ratio that matches the maximum motor output for high jumping was selected. Then, the following strategies to further exploit the motor output performance was examined: (1) to set the maximum torque of each joint as the baseline that is explicitly modeled as a piecewise linear function dependent on the joint angular velocity; (2) to exert it with a correction of the joint angular accelerations in order to satisfy some balancing criteria during the motion. The criteria include the location of ZMP (zero moment point) and the torque limit. Using the technique described above, the jumping pattern is pre-calculated to maximize the jump height. Finally, the effectiveness of the proposed method is evaluated through simulations. In the simulation, the bipedal robot model achieved a 0.477-m high jump.

A Review of Atif Mian and Amir Sufi’s House of Debt

House of Debt by Atif Mian and Amir Sufi provides a pattern of large jumps in household debt and drops in spending preceding economic disasters. Based on national and international evidence, this book describes the way debt exacerbated the Great Recession, and also interprets the reasons why debt keeps on threatening the global economy, and what requires to be done to fix the financial system such as equity-like contracts.

Characteristics of Hydraulic Jump in U-Shaped Channels

A hydraulic jump is the rapid transition from a supercritical to subcritical flow. This transition is characterized by large-scale turbulence and energy dissipation. Despite the importance of understanding the hydraulic jump to design hydraulic structures, few studies have aimed on hydraulic jumps in U-shaped channels. In this paper, the 3D pattern of hydraulic jumps in U-shaped channels is studied numerically. The variations of the flow free surface are predicted using the volume of fluid scheme. Also, the flow field turbulence is simulated using the standard $$k-\varepsilon $$ and RNG $$k-\varepsilon $$ turbulence models. According to the numerical modeling results, the standard $$k-\varepsilon $$ turbulence model estimates the flow characteristics with more accuracy. A comparison between the laboratory and numerical results shows that the numerical model simulates the flow field characteristics with good accuracy. For example, in the hydraulic jump model with a relative discharge $$({q=Q/{\sqrt{( {gD^{5}})}}})$$ equal to 0.321 and a Froude number $$({{F}_1})$$ equal to 4.85, the values of MAPE, RMSE and $${R}^{2}$$ are calculated 7.617, 0.022 and 0.989, respectively. Next, 45 numerical models are simulated in different hydraulic conditions and some relationships are provided for calculating the sequent depth $$({{h_2 }/{h_1 }})$$ , hydraulic length $$({{L_\mathrm{j}}/{h_1}})$$ and roller length $$({{L_\mathrm{r} }/{h_1}})$$ ratios by analyzing their results.

Adaptive Rendezvous for Heterogeneous Channel Environments in Cognitive Radio Networks

Rendezvous is the fundamental challenge in cognitive radio networks to find each other on a specific channel and establish a communication link. The primary focus of this paper is to design an algorithm for blind rendezvous, i.e., a rendezvous without a coordinator or common control channel. Channels to jump are assumed to be homogeneous in prior work; however, in the real world, channels exhibit different conditions. Therefore, we propose an adaptive jumping pattern such that a superior channel is considered more frequently based on its noise level and users have a greater possibility to rendezvous on such a channel. Furthermore, in this paper, we investigate the rendezvous problem with multiple radio interfaces. When multiple radio interfaces are available for users, the possibility of rendezvous increases; however, the number of channels to jump for each interface may not be the same as other users’ interfaces. We propose an adaptive rendezvous algorithm that can function for multiple interfaces and different sizes of channel lists and an adaptive jumping pattern for different channel conditions. We prove that the proposed algorithm provides guaranteed rendezvous and derive the maximum time-to-rendezvous (TTR), which is also verified via simulation results. Further, our algorithm outperforms jump-and-stay in terms of TTR while enabling users to rendezvous on a better channel.

児童におけるなわ跳び動作の発達とその観察的な評価

児童におけるなわ跳び動作の発達とその観察的な評価

The age pattern of transitory mortality jumps and its impact on the pricing of catastrophic mortality bonds

To value catastrophic mortality bonds, a number of stochastic mortality models with transitory jump effects have been proposed. Rather than modeling the age pattern of jump effects explicitly, most of the existing models assume that the distributions of jump effects and general mortality improvements across ages are identical. Nevertheless, this assumption does not seem to be in line with what we observe from historical data. In this paper, we address this problem by introducing a Lee–Carter variant that captures the age pattern of mortality jumps by a distinct collection of parameters. The model variant is then further generalized to permit the age pattern of jump effects to vary randomly. We illustrate the two proposed models with mortality data from the United States and English and Welsh populations, and use them to value hypothetical mortality bonds with similar specifications to the Atlas IX Capital Class B note that was launched in 2013. It is found that the features we consider have a significant impact on the estimated prices.

The effects of altered distances between obstacles on the jump kinematics and apparent joint angulations of large agility dogs

Canine agility is a rapidly growing sport in the UK. However, there is a paucity of scientific research examining jump kinematics and associated health and welfare implications of the discipline. The aim of this research was to examine differences in jump kinematics and apparent joint angulation of large (>431 mm at the withers) agility dogs (n = 54), when the distance between hurdles was altered (3.6 m, 4 m and 5 m apart) and to determine how level of skill impacted upon jump kinematics.Significant differences were observed for both the take-off (P < 0.001) and landing distances (P < 0.001) between the 3.6 m, 4 m and 5 m distances. Further differences were observed when level of skill was controlled for; take-off (F[3,55] = 5.686, P = 0.002) and landing (F[3,55] = 7.552, P < 0.001) distances differed at the 3.6 m distance, as did the take-off distance at the 4 m hurdle distance (F[3,50] = 6.168, P = 0.001). Take-off and landing speeds differed for hurdle distances (P < 0.001) and level of skill (P < 0.001). There were significant differences in apparent neck angle during take-off and landing (P < 0.001), lumbar spine angles during take-off, bascule and landing (P < 0.01), and in shoulder angles during the bascule phase (P < 0.05). The results indicate that agility dogs alter their jumping patterns to accommodate the spacing between hurdles, which ultimately may impact long term health and welfare due to altered kinematics.

Characteristics of the Velocity Distribution in a Hydraulic Jump Stilling Basin with Five Parallel Offset Jets in a Twin-Layer Configuration

The flow structure of vertical and horizontal planes in a stilling basin with five parallel offset jets in a twin-layer configuration for four offset ratios (S1/h=1,2,3,4) has been investigated. The velocity distribution was measured, processed, and subsequently used to characterize the flow structure. The flow pattern in the stilling basin exhibits a mixing flow pattern of jets and hydraulic jumps. As the downstream water depth increases in the stilling basin, five different flow patterns appear successively: free jets, hydraulic jumps, submerged jets and hydraulic jumps, mixed submerged jets and critical jumps, and mixed submerged jets and submerged jumps. The results indicate that the velocity distributions in the vertical and horizontal planes of the lower-layer orifices and in the potential core region of the upper-layer orifices are similar to the classical jet; in other regions, the velocity distribution is similar to the hydraulic jump. In addition, the energy dissipation ratio increases with the increasing Froude number, with a value of greater than 70% at F>8.0. The energy dissipation ratio in the stilling basin with five parallel offset jets in a twin-layer configuration is, on average, 5% larger than that of the SBJ basin and 13% larger than that of the classical jump basin.

The benefit of modeling jumps in realized volatility for risk prediction: Evidence from Chinese mainland stocks

Recent literature has focused on realized volatility models to predict financial risk. This paper studies the benefit of explicitly modeling jumps in this class of models for value at risk (VaR) prediction. Several popular realized volatility models are compared in terms of their VaR forecasting performances through a Monte Carlo study and an analysis based on empirical data of eight Chinese stocks. The results suggest that careful modeling of jumps in realized volatility models can largely improve VaR prediction, especially for emerging markets where jumps play a stronger role than those in developed markets.

G151013 直立からの跳躍,着地が可能な一脚ジャンピングロボットの開発([G151-01]ロボティクスメカトロニクス部門,一般セッション(1))

This paper describes the posture control of vertical jumping pattern for an one-legged jumping robot.The jumping robot is can jump from standing to landing.The jumping robot has a total of 13 actuators: 10 mono-articular types and 3 bi-articular types.The problem using pneumatic actuator is difficult to keep the fine posture.Therefore,our target is to keep the fine posture after landing.For a vertical jump,a joint angle pattern is developed based on the linear momentum and the angular momentum.The effectiveness of the mechanism and the jumping pattern of the jumping robot areverified through simulation and experiments.

Retracted: A Jumping Pattern Generation for the Biped Robot

Retracted: A Jumping Pattern Generation for the Biped Robot

Effects of Jump Training with Negative versus Positive Loading on Jumping Mechanics

We examined the effects of jump training with negative (-30% of the subject's body weight (BW)) VS. positive loading (+30% BW) on the mechanical behaviour of leg extensor muscles. 32 men were divided into control (CG), negative loading (NLG), or positive loading training group (PLG). Both training groups performed maximal effort countermovement jumps (CMJ) over a 7-week training period. The impact of training on the mechanical behaviour of leg extensor muscles was assessed through CMJ performed with external loads ranging from -30% BW to +30% BW. Both training groups showed significant ( P≤0.013) increase in BW CMJ height (NLG: 9%, effect size (ES)=0.85, VS. PLG: 3.4%, ES=0.31), peak jumping velocity ( V(peak); NLG: 4.1%; ES=0.80, P=0.011, VS. PLG: 1.4%, ES=0.24; P=0.017), and depth of the countermovement (Δ H(ecc); NLG: 20%; ES=-1.64, P=0.004, VS. PLG: 11.4%; ES=-0.86, P=0.015). Although the increase in both the V(peak) and Δ H(ecc) were expected to reduce the recorded ground reaction force, the indices of force- and power-production characteristics of CMJ remained unchanged. Finally, NLG (but not PLG) suggested load-specific improvement in the movement kinematic and kinetic patterns. Overall, the observed results revealed a rather novel finding regarding the effectiveness of negative loading in enhancing CMJ performance which could be of potential importance for further development of routine training protocols. Although the involved biomechanical and neuromuscular mechanisms need further exploration, the improved performance could be partly based on an altered jumping pattern that utilizes an enhanced ability of leg extensors to provide kinetic and power output during the concentric jump phase.

Does Decomposing Realized Volatility Help in Risk Prediction: Evidence from Chinese Mainland Stocks

This article studies the risk forecasting properties of three realized volatility models for three Chinese individual stocks, and reveals the important role that jumps can play in risk prediction. I firstly investigate dynamic pattern of jumps in three Chinese stocks, and find that relative to developed markets, jumps in this emerging market are more predictable and account for a larger proportion in realized volatility. Further, I compare the Value-at-risk (VaR) forecasting performances of three commonly used realized volatility models for the three Chinese stocks. Two-step VaR backtesting shows that a newly proposed realized volatility forecasting model (Andersen et al, 2007), which separately treats jumps and the continuous sample path of the asset price, provides more accurate VaR prediction than two other competing models, that treat realized volatility as a single variable. These findings suggest that carefully modelling of jumps is important in risk prediction, especially for emerging markets where jumps play a stronger role than those in developed markets.