Average Moment Research Articles

The Effect of Footwear on Free Moments During a Rotational Movement in Country Swing Dance.

Footwear in dance has been studied for support and cushioning, but little research has been conducted on free moments, which may result from high frictional coefficients. Conversely, insufficient friction between shoes and floors may increase the risk of falls and compromise dance performance. The purpose of this study was to examine the effect of different types of footwear with different coefficients of friction on peak and average free moments during a rotational movement in country swing dance. Fifteen country swing dancers completed a rotational movement under four footwear conditions: barefoot, rubber-bottom boots, leather-bottom boots, and running shoes. The peak and average free moments applied to the left and right legs were measured using two force plates. Coefficients of static friction between different shoes and force plate surfaces were quantified and found to be greater for the rubber-bottom boots and running shoes than the leather-bottom boots. For the left (push off) leg, free moments were greater for the running shoe and rubber-bottom boot conditions compared to the barefoot and leather-bottom boot conditions. For the right (rotating) leg, free moments were greatest for the running shoe condition, second greatest for the barefoot and rubber-bottom boot conditions, and least for the leather-bottom boot condition. The leatherbottom boots may decrease twisting loads resulting from free moments. Coefficients of friction and free moments should be considered for future longitudinal studies to investigate potential cause-effect relationships among footwear, potential for injury, and dance performance.

Validation of method for analysing mechanics of unloader brace for medial knee osteoarthritis

Unloader braces are one non-invasive treatment of knee osteoarthritis, which primarily function by applying an external abduction moment to the joint to reduce loads in the medial compartment of the knee. We developed a novel method using brace deflection to estimate the mechanical effect of valgus braces and validated this model using strain gauge instrumentation.Three subjects performed static and walking trials, in which the moment applied by an instrumented brace was calculated using the deflection and strain methods. The deflection method predicted average brace moments of 8.7 Nm across static trials; mean error between the deflection model predictions and the gold-standard strain gauge measurements was 0.32 Nm. Mean brace moment predictions throughout gait ranged from 7.1 to 8.7 Nm using the deflection model. Maximum differences (MAE) over the gait cycle in mean and peak brace moments between methods were 1.50 Nm (0.96) and 0.60 Nm (0.42).Our proposed method enables quantification of brace abduction moments without the use of custom instrumentation. While the deflection-based method is similar to that implemented by Schmalz et al. (2010), the proposed method isolates abduction deflection from the 3 DOF angular changes that occur within the brace. Though the model should be viewed with more caution during swing (MAE = 1.16 Nm), it was shown that the accuracy is influenced by the uncertainty in angle measurement due to cluster spacing. In conclusion, the results demonstrate that the deflection-based method developed can predict comparable brace moments to those of the previously established strain method.

Seismic response of skewed bridges including pounding effects

The seismic vulnerability of skewed bridges had been observed in many past earthquakes. Researchers have found that the in-plane rotation of the girders was one of the main reasons for the vulnerability of these types of bridges. To date, not many experimental works have been done on this topic, especially those including pounding between adjacent structures. In this study, shake table tests were performed on a bridge-abutment system consisting of a straight, 30o, and 45o bridge with and without considering pounding. Skewed bridges with the same fundamental frequency and those having the same girder mass as the straight bridge were studied. Under the loadings considered, skewed bridges with the same frequency as the straight tend to have smaller responses than those with the same mass. The average maximum bending moment developed in the piers of the 30o bridge with the same mass as that of the straight when pounding was not considered was 1.6 times larger than when the frequencies were the same. It was also found that the NZTA recommendations for the seat lengths of skewed bridges could severely underestimate the relative displacements of these types of bridges in the transverse direction, especially when pounding occurs. In the worst case, the average transverse displacement of the 45o bridge was about 2.6 times the longitudinal displacement of the straight, which was greatly over the limit suggested by the NZTAof 1.25 times.

Validity and Practitality of Acid-Base Module Based on Guided Discovery Learning for Senior High School

This Research and Development(R&D) aims to produce guided discovery learning based module on topic of acid-base and determine its validity and practicality in learning. Module development used Four D (4-D) model (define, design, develop and disseminate).This research was performed until development stage. Research’s instruments were validity and practicality questionnaires. Module was validated by five experts (three chemistry lecturers of Universitas Negeri Padang and two chemistry teachers of SMAN 9 Padang). Practicality test was done by two chemistry teachers and 30 students of SMAN 9 Padang. Kappa Cohen’s was used to analyze validity and practicality. The average moment kappa was 0.86 for validity and those for practicality were 0.85 by teachers and 0.76 by students revealing high category. It can be concluded that validity and practicality was proven for high school chemistry learning.

Influence of steel–concrete bond damage on the dynamic stiffness of cracked reinforced concrete beams

In this article, experiments focusing at the influence of steel–concrete bond damage on the dynamic stiffness of cracked reinforced concrete beams are reported. In these experiments, the bond between concrete and reinforcing bar was damaged using appreciate flexural loads. The static stiffness of cracked reinforced concrete beam was assessed using the measured load–deflection response under cycles of loading and unloading, and the dynamic stiffness was analyzed using the measured natural frequencies with and without sustained loading. Average moment of inertia model (Castel et al. model) for cracked reinforced beams by taking into account the respective effect of bending cracks (primary cracks) and the steel–concrete bond damage (interfacial microcracks) was adopted to calculate the static load–deflection response and the natural frequencies of the tested beams. The experimental results and the comparison between measured and calculated natural frequencies show that localized steel–concrete bond damage does not influence remarkably the dynamic stiffness and the natural frequencies both with and without sustained loading applied. Castel et al. model can be used to calculate the dynamic stiffness of cracked reinforced concrete beam by neglecting the effect of interfacial microcracks.

Posterior or anterolateral approach in hip joint arthroplasty - Impact on frontal plane moment

BackgroundAnterolateral surgical approach in hip joint arthroplasty necessitates division of the hip abductor muscle complex, which may compromise postoperative gait observed in the frontal plane. The aim of the study was to compare frontal plane moment after hip joint arthroplasty by anterolateral or posterior approach and to explore which compensatory strategies patients use to decrease frontal plane moment. MethodsTwenty-eight patients were randomized by sealed envelopes to hip resurfacing arthroplasty surgery by anterolateral (ad modum Watson) or posterior (ad modum Moore) approach, performed by two senior surgeons. Gait analyses were performed using 3D motion capture before surgery, 3, and 12 months after surgery. Peak ground reaction force was extracted for early and late stance and the corresponding frontal plane moment was defined. Measures of lateral trunk inclination, pelvic drop and hip abduction were obtained for the stance phase of the affected leg. FindingsAn effect of surgical approach on frontal plane moment for the affected leg was found during early stance phase (p = 0.006) where average frontal plane moment in the anterolateral groups was 202.42 N mm/kg in less compared to the posterior group after one year. A similar effect from baseline to 12 months for trunk inclination (p = 0.03) and an overall negative correlation between frontal plane moment and trunk inclination was found (r = −0.66, p = 0.03). InterpretationFrontal plane moment during early stance was less one year after hip joint arthroplasty through anterolateral compared to posterior approach. Patients' primary strategy to reduce frontal plane moment seems to be increased lateral trunk inclination.

Rare-Earth Fourth-Order Multipole Moment in Cubic ErCo2Probed by Linear Dichroism in Core-Level Photoemission

We developed a method to experimentally quantify the fourth-order multipole moment of the rare-earth 4f orbital. Linear dichroism (LD) in the Er 3d5/2 core-level photoemission spectra of cubic ErCo2 was measured using bulk-sensitive hard X-ray photoemission spectroscopy. Theoretical calculation reproduced the observed LD, and the result showed that the observed result does not contradict the suggested \(\Gamma _{8}^{3}\) ground state. Theoretical calculation further showed a linear relationship between the LD size and the size of the fourth-order multipole moment of the Er3+ ion, which is proportional to the expectation value \(\langle O_{4}^{0} + 5O_{4}^{4}\rangle \), where \(O_{n}^{m}\) are the Stevens operators. These analyses indicate that the LD in 3d photoemission spectra can be used to quantify the average fourth-order multipole moment of rare-earth atoms in a cubic crystal electric field.

Unsteady Aerodynamic Forces and Power Consumption of a Micro Flapping Rotary Wing in Hovering Flight

The micro Flapping Rotary Wing (FRW) concept inspired by insects was proposed recently. Its aerodynamic performance is highly related to wing pitching and rotational motions. Therefore, the effect of wing pitching kinematics and rotational speed on unsteady aerodynamic forces and power consumption of a FRW in hovering flight is further studied in this paper using computational fluid dynamics method. Considering a fixed pitching amplitude (i.e., 80°), the vertical force of FRW increases with the downstroke angle of attack and is enhanced by high wing rotational speed. However, a high downstroke angle of attack is not beneficial for acquiring high rotational speed, in which peak vertical force at balance status (i.e., average rotational moment equals zero.) is only acquired at a comparatively small negative downstroke angle of attack. The releasing constraint of pitching amplitude, high rotational speed and enhanced balanced vertical force can be acquired by selecting small pitching amplitude despite high power consumption. To confirm which wing layout is more power efficient for a certain vertical force requirement, the power consumed by FRW is compared with the Rotary Wing (RW) and the Flapping Wing (FW) while considering two angle of attack strategies without the Reynolds number (Re) constraint. FRW and RW are the most power efficient layouts when the target vertical force is produced at an angle of attack that corresponds to the maximum vertical force coefficient and power efficiency, respectively. However, RW is the most power efficient layout overall despite its insufficient vertical force production capability under a certain Re.

Piezoelectric Earcanal Bending Sensor

The earcanal shape is unique for each human being and temporarily changes when the jaw moves due to eating, chewing, or speaking. The earcanal deformation can be studied by the geometrical analysis of a distorted earpiece custom-fitted inside the earcanal, but the distortion of the earpiece is complex in nature and complicated to analyze. An earcanal bending sensor consisting of a thin piezoelectric strip attached to a custom-fitted earpiece is presented in this paper. An analytical approach based on computing the geometrical parameters of distorted and undistorted earpieces is developed to: 1) estimate the average bending moment and the resulting stress applied to the custom-fitted earpiece while opening the jaw and 2) calculate the sensitivity of the piezoelectric earcanal bending sensor. The theoretical model is experimentally validated. The proposed approach can be applied to measure the bending of any curved body in general, and custom-fitted earpieces in particular. It, therefore, enables the designing of versatile in-ear sensors capable of tracking jaw activity and evaluating the energy capacity of earcanal deformation for in-ear energy harvesting purposes.

The Effect of Weak Confinement on the Orientation of Nanorods under Shear Flows.

We performed a numerical analysis to study the orientation distribution of a dilute suspension of thin, rigid, rod-like nanoparticles under shearing flow near a solid boundary of weak confinement. Brownian dynamics simulation of a rod was performed under various ratios of shear rate and rod diffusivity (Peclet number), as well as the center-of-mass position (wall confinement). We discuss the effects of Peclet number and wall confinement on the angle distributions, Jeffery orbit distribution and average orientation moments. The average orientation moments, obtained as a function of Peclet number and wall confinement, can be used to improve a previous shear-induced migration model. We demonstrate that the improved model can give excellent prediction of the orientation moment distributions in a microchannel flow.

Large moments in bcc FexCoyMnz ternary alloy thin films

The elemental magnetic moments and the average atomic moment of 10–20 nm thick single crystal bcc (bct) FexCoyMnz films deposited on MgO(001) have been determined as a function of a broad range of compositions. Thin film epitaxy stabilized the bcc structure for 80% of the available ternary compositional space compared to only a 23% stability region for the bulk. The films that display ferromagnetism represent 60% of the available compositional possibilities compared to 25% for the bulk. A maximum average atomic moment of 3.25 ± 0.3 μB/atom was observed for a bcc Fe9Co62Mn29 film (well above the limit of the Slater-Pauling binary alloy curve of 2.45 μB/atom). The FexCoyMnz ternary alloys that exhibit high moments can only be synthesized as ultrathin films since the bcc structure is not stable in the bulk for those compositions.

The dramatic enhancement of ferromagnetism and band gap in Fe-doped In2O3 nanodot arrays

Ordered Fe-doped In2O3 nanodot arrays with diameters between 35 nm and 80 nm are fabricated using pulsed laser deposition with the aid of ultrathin porous anodized aluminumoxide templates. The 5 at.% Fe doped In2O3 nanodot arrays are shown to consist of the cubic bixbyite structure of In2O3. The nanodot arrays are demonstrated to be doped by Fe ions with mixed valences of +2 and +3, ruling out the presence of cluster and secondary phase related to Fe. The nanodot arrays exhibit the ferromagnetism at room temperature, where the magnetic moment increases as the dot size is reduced, rising to a maximum of about 230 emu/cm3 (equivalent to an average moment on the Fe ions of 15.30 µB/Fe). This indicates an effect due to the surface of the nanodot arrays. The optical band width is also increased to 4.55 eV for the smallest dot array, thus indicating that the surface states are responsible for the magnetism and also enhance the band gap due to Burstein-Moss effect. Our results will be benefit for understanding the physical properties of oxide semiconductor nanostructures in the application of nano-spintronics devices.

On the Reliability of Serviceability Calculations for Flexural Cracked Reinforced Concrete Beams

Under in-service conditions, beams and slabs in reinforced concrete structures are almost always cracked, as the tensile strength of the concrete is low. Due to the irreversible reduction in overall stiffness resulting from cracking and the residual deflection after unloading, the structural response is load path dependent. In this paper, an existing average moment of inertia model and Monte Carlo simulation (MCS) are adopted to take into account the effect of historical cracking damage on the reliability of serviceability calculations for reinforced concrete (RC) members. The suitability of the average moment of inertia model for reliability analysis is verified by considering experimental tests on a total of eleven reinforced concrete beams. The errors associated with both the effective and average moment of inertia predicted by the model are calibrated using the experimental data. By using the proposed approach to account for the various sources of uncertainty in reinforced concrete beams, the quantitative loss in the short-term and long-term serviceability reliability of a cracked reinforced concrete beam was calculated. The results confirm that the effect of historical cracking damage on short-term serviceability reliability should be taken into account when the deflection induced by historical loading is larger than the deflection limitation. Light historical damage has no influence on the short-term serviceability reliability, although it affects the probability density distribution of the deflection. However, in the long-term serviceability reliability analysis, even when the historical damage is light, the long-term serviceability reliability index is decreased as the cracking damage to the stiffness affects the time-dependent deflection. Additionally, the later a damaging load is applied to a reinforced concrete beam, the less is the influence of cracking damage on the long-term serviceability reliability.

KEMAMPUAN BERPIKIR KRITIS MAHASISWA MANAJEMEN UMSIDA DALAM MEMECAHKAN MASALAH MATEMATIKA BISNIS

This descriptive study used a quantitative approach that aims at describing the students' critical thinking in solving business mathematics problems with respect to the origin of the school majors. Subjects were students of FEB management UMSIDA first half of the academic year 2016/2017. Data collection techniques in the form of tests to complete the Problem Solving Test (TPM) and the provision of critical thinking questionnaire relating to the work of students on TPM has been given. Data were analyzed using the average, percentage and Pearson Product Moment Correlation test (PPM). And the results showed that (1) the ability to solve business mathematics problems, student majoring in science studies is higher than the ability to solve mathematical problems business student majoring in social studies or student majoring in vocational school (2) critical thinking skills of students majoring in science studies, social studies and vocational school overall thinking ability critical successively shows the critical criterion, quite critical and critical enough (3) critical thinking skills of students at every step of Polya’s Problem Solving as follows: (a) at the stage Understanding the problem, a student of the science studies showed criteria please critical, a student of the social studies indicate criteria quite Critical and student of vocational school indicate the criteria fairly Critical (b) at the stage Make a Plan, a student of the science studies indicates the criteria fairly critical, a student of the social studies indicate criteria is quite critical and student of vocational school indicate the criteria fairly Critical (c) at the stage implement the plan, a student of the science studies showed criteria please Critical, a student of the social studies indicate criteria please Critical and student of vocational school indicate criteria please Critical (c) at the stage Checking Back, a student of the science studies indicates the criteria Critical, a student of the social studies show Critical criteria and student of vocational schools show the criteria, please Critical (4) there is a strong relationship between Business Mathematics problem Solving ability with Students Critical Thinking Skills.
 Keywords: evaluation of learning, realibility, discrimination power

Shocks vs Menu Costs: Patterns of Price Rigidity in an Estimated Multi-Sector Menu-Cost Model

Relying on a menu-cost model augmented with a time-dependent (Calvo) component, we investigate the structural sources of cross-sectoral heterogeneity in patterns of price setting. We use a large micro dataset of French consumer prices to estimate the model at the product level for 227 products. The Calvo component is found to be large in most sectors. Heterogeneity in structural parameters is also substantial. The combination of these two features leads to much larger real effects of monetary policy. The effect of monetary shock on output is more than 4 times larger than the one derived from a standard single-sector menu-cost model estimated using average moments.

ОЦЕНКА ЭФФЕКТИВНОСТИ УСТРОЙСТВА «КОИЛБОКС» НА СТАНЕ 1680

The aim of the work is to conduct a comparative analysis of the results of rolling hot-rolled strips in the finishing group of mill stands of 1680 strips with and without the use of an intermediate rewinding device (PUF). A comparative analysis of the results of measurements of the moment and longitudinal thickness during rolling in the finishing group of stands is given. Given the distribution of torque in the cages along the length of the strip. It is shown that the mean square deviation of the moment is noticeably less than the rolling time without PUF. The level of dynamic loads and the dynamic factor of the moment of elastic force during the rolling of bands with polyurethane foam and without polyurethane foam practically did not change. It is shown that when rolling without PUF on the finished strip there remains a trace of the temperature wedge in the form of a wedge of thickness. When rolling with PUF, the thickness of the strip along its length becomes more uniform. When rolling without PUF, a trace of a wedge of thickness in the form of a wedge remains on the finished strip. When rolling with PUF, the thickness of the strip along its length becomes more uniform. In general, a comparison of the average moment along the stripes, the standard deviation, the coefficient of variation of the moment and the deviation of the thickness shows the advantages of rolling with PUF.

Moment‐Volume Coupling in La(Fe1−xSix)13

We investigate the origin of the volume change and magnetoelastic interaction observed at the magnetic first‐order transition in the magnetocaloric system La(Fe1−xSix)13 by means of first‐principles calculations combined with the fixed‐spin moment approach. We find that the volume of the system varies with the square of the average local Fe moment, which is significantly smaller in the spin disordered configurations compared to the ferromagnetic ground state. The vibrational density of states obtained for a hypothetical ferromagnetic state with artificially reduced spin‐moments compared to a nuclear inelastic X‐ray scattering measurement directly above the phase transition reveals that the anomalous softening at the transition essentially depends on the same moment‐volume coupling mechanism. In the same spirit, the dependence of the average local Fe moment on the Si content can account for the occurence of first‐ and second‐order transitions in the system.

Bounding Averages Rigorously Using Semidefinite Programming: Mean Moments of the Lorenz System

We describe methods for proving bounds on infinite-time averages in differential dynamical systems. The methods rely on the construction of nonnegative polynomials with certain properties, similarly to the way nonlinear stability can be proved using Lyapunov functions. Nonnegativity is enforced by requiring the polynomials to be sums of squares, a condition which is then formulated as a semidefinite program (SDP) that can be solved computationally. Although such computations are subject to numerical error, we demonstrate two ways to obtain rigorous results: using interval arithmetic to control the error of an approximate SDP solution, and finding exact analytical solutions to relatively small SDPs. Previous formulations are extended to allow for bounds depending analytically on parametric variables. These methods are illustrated using the Lorenz equations, a system with three state variables $(x,y,z)$ and three parameters $(\beta,\sigma,r)$. Bounds are reported for infinite-time averages of all eighteen moments $x^ly^mz^n$ up to quartic degree that are symmetric under $(x,y)\mapsto(-x,-y)$. These bounds apply to all solutions regardless of stability, including chaotic trajectories, periodic orbits, and equilibrium points. The analytical approach yields two novel bounds that are sharp: the mean of $z^3$ can be no larger than its value of $(r-1)^3$ at the nonzero equilibria, and the mean of $xy^3$ must be nonnegative. The interval arithmetic approach is applied at the standard chaotic parameters to bound eleven average moments that all appear to be maximized on the shortest periodic orbit. Our best upper bound on each such average exceeds its value on the maximizing orbit by less than 1%. Many bounds reported here are much tighter than would be possible without computer assistance.

Hydrodynamic characteristic of synthetic jet steered underwater vehicle

In this paper, the hydrodynamic characteristic of a synthetic jet steered underwater vehicle is studied. The steering motion studied is the lateral motion and the yaw motion. The lateral motion is induced through the in-phase work of this two actuators and the yaw motion is realized through the out-of-phase work. The vehicle studied is REMUS AUV with synthetic jet actuator mounted inside. The hydrodynamic characteristic of the vehicle under different cruising speed is studied. The driving parameters of the SJ actuator keep invariant in different cases. When the two actuators work in phase, the average steering force is smaller than the thrust of the isolated actuator and keeps nearly invariant under different cruising speed. When the two actuators work out of phase, the average steering moment also keeps invariant with cruising speed. The mathematical model of the additional drag of the vehicle, the thrust of the actuator, the steering force as well as the steering moment is given. The velocity distribution is also given to assistant the analysis in this paper. From the analysis given it can be known the steering method based on SJ is realized through position control other than velocity control.

Rotational Spectroscopy of p-Toluic Acid and Its 1:1 Complex with Water.

The structure and internal dynamics of p-toluic acid and its 1:1 complex with water were investigated in the gas phase using chirped-pulse and cavity-based Fourier transform microwave spectroscopy. One conformer and one isomer were identified for the monomer and monohydrate, respectively. In the monohydrate, water acts as both a hydrogen bond donor and acceptor, participating in a six-membered intermolecular ring with the carboxyl group. Both a- and b-type transitions were observed for the monomer; only a-type transitions were observed for the monohydrate. Rotational transitions of both species show splittings originating from methyl internal rotation, for which the potentials include 3- and 6-fold symmetry terms of similar amplitude. For the monomer, a few b-type transitions are missing, and their intensities were found to be transferred to c-type transitions with common energy levels, which are otherwise forbidden. No splittings attributable to a water internal tunneling motion were observed for the monohydrate. Furthermore, the absence of c-type transitions in the spectrum of the monohydrate, despite the large μc dipole moment component of the equilibrium geometry obtained by ab initio calculations, is consistent with a barrierless wagging motion of the free hydrogen of water, leading to an average μc dipole moment component of zero. These results provide insights regarding the interactions between atmospheric p-toluic acid and water in prenucleation complexes and at the air-water interface of aqueous aerosols, where p-toluic acid may act as a surfactant.