Average Acceleration Research Articles

A fully explicit staggered algorithm for near‐field wave propagation of fluid‐saturated porous media based on u‐p dynamic formulation

AbstractNear‐field wave propagation of the fluid‐saturated porous media (FSPM) is an important issue in soil dynamics and geotechnical earthquake engineering. In the current study, a fully explicit staggered algorithm for the near‐field wave propagation analysis of the FSPM in the time domain is developed based on the u‐p dynamic formulation. The decoupling of dynamic formulation is implemented by the diagonalization of the mass matrix and pore fluid compressibility matrix. The central difference method and Newmark constant average acceleration method are used for the solution of the displacement and velocity of solid skeleton, and the backward difference method is used for the solution of pore fluid pressure in the time domain. The effectiveness and feasibility of the matrix diagonalization are verified by the comparison with the classical numerical algorithm. The proposed algorithm is also validated by the comparison of the numerical results with the corresponding analytical solution results. Combing with the transmitting artificial boundary condition, the proposed algorithm is then applied to investigate the seismic response of a FSPM free field, and its applicability to the typical near‐field wave propagation problems of the FSPM is indicated. The stability analysis of the proposed algorithm is finally conducted, and the corresponding stability criterion is presented. For the proposed algorithm, all the dynamic variables of the FSPM are solved in an iterative way and the coupling dynamic equations need not to be solved at each time step. The computational effort can be reduced considerably, and the computational efficiency can be improved remarkably.

A More Intense Examination of the Intensity of Physical Activity in People Living with Chronic Obstructive Pulmonary Disease: Insights from Threshold-Free Markers of Activity Intensity.

Physical activity (PA) intensity of people living with chronic obstructive pulmonary disease (COPD) is typically evaluated using intensity thresholds developed in younger, healthier populations with greater exercise capacity and free from respiratory symptoms. This study therefore compared (i) PA differences between COPD and non-COPD controls using both traditional intensity thresholds and threshold-free metrics that represent the volume and intensity of the whole PA profile, and (ii) explored the influence of exercise capacity on observed differences. Moderate-to-vigorous physical activity (MVPA), average acceleration (proxy for volume, mg) and intensity distribution of activity were calculated for 76 individuals with COPD and 154 non-COPD controls from wrist-worn ActiGraph accelerometry. PA profiles representing the minimum intensity (acceleration, mg) during the most active accumulated 5–960 min were plotted. Estimated VO2peak and relative intensity were derived from the incremental shuttle walk test distance. Compared to the non-COPD control group, individuals with COPD recorded fewer MVPA minutes (59 vs. 83 min/day), lower overall waking activity (29.1 vs. 36.4 mg) and a poorer waking intensity distribution (−2.73 vs. −2.57). Individuals with COPD also recorded a lower absolute intensity (acceleration, mg) for their most active 5–960 min, but higher intensity relative to their estimated exercise capacity derived from the ISWT. People with COPD have a lower volume and absolute intensity of PA than controls but perform PA at a higher relative intensity. There is a need to move away from absolute intensity thresholds, and towards personalised or relative-intensity thresholds, to reflect reduced exercise capacity in COPD populations.

Hydrophilic porous materials as helmet padding able to prevent traumatic brain injuries

The ideal way to reduce the likelihood of traumatic brain injuries for a player engaged in an impact sport such as football or hockey, as a result of an impact of his/her helmet with a surface or another player, would be to reduce the average value of the acceleration of the player's head in an impact as much as possible. The minimum possible value of the average deceleration of the head is inversely proportional to the helmet padding thickness. Since there are practical limits to its maximum thickness, it is difficult to significantly reduce the average acceleration. There is evidence, however, that the peak, rather than the average, acceleration is the most significant cause of brain injury. It is proposed here that brain injuries, that occur as a result of an impact, could be reduced by using as padding a hydrophilic porous material swollen with fluid. The friction experienced by the fluid as it is squeezed out of the porous material in an impact can “tune” the acceleration of the skull so that it is never significantly higher than its average value during the impact.

Influence of the transient airflow pattern on the temporal evolution of microparticle resuspension: Application to ventilated duct during fan acceleration

This study investigates experimentally the influence of the temporal airflow pattern properties to which microparticles are exposed on the dynamics of the resuspension phenomenon for transient airflow conditions representative of a fan start, i.e., involving a temporal acceleration period before reaching steady state. The extent to which the average steady state velocity and the average acceleration affect the characteristics of the curve depicting the temporal evolution of the fraction of particles remaining on the duct wall, i.e., the time at which resuspension starts and the curve shape, is investigated. These results are analyzed regarding the properties of the instantaneous velocity signal in the viscous sublayer. It is demonstrated that a threshold turbulent kinetic energy must be exceeded for resuspension to begin. The results are also presented in terms of resuspension rate, i.e., of instantaneous rate of particles removed from the duct surface, versus time. This enables to demonstrate that the highest resuspension rate values are recorded at the very beginning of the phenomenon, typically during the fan acceleration stage, and that high mean acceleration values are responsible for high resuspension rates.Copyright © 2022 American Association for Aerosol Research

Physical Activity in Centenarians beyond Cut-Point-Based Accelerometer Metrics.

This study described and compared physical activity (PA) characteristics at the end of the human lifespan using conventional cut-point-based versus cut-point-free accelerometer metrics. Eighteen institutionalized centenarians (101.5 ± 2.1 years, 72.2% female, 89% frail) wore the wrist GENEActiv accelerometer for 7 days. Conventional metrics, such as time spent in light-intensity PA (LiPA) and moderate-to-vigorous intensity PA (MVPA) were calculated according to published cut-points for adults and older adults. The following cut-point-free metrics were evaluated: average acceleration, intensity gradient and Mx metrics. Depending on the cut-point, centenarians accumulated a median of 15–132 min/day of LiPA and 3–15 min/day of MVPA. The average acceleration was 9.2 mg [Q1: 6.7 mg–Q3: 12.6 mg] and the intensity gradient was −3.19 [−3.34–−3.12]. The distribution of Z-values revealed positive skew for MVPA, indicating a potential floor effect, whereas the skew magnitude was attenuated for cut-point-free metrics such as intensity gradient or M5. However, both cut-point-based and cut-point-free metrics were similarly positively associated with functional independence, cognitive and physical capacities. This is the first time that PA has been described in centenarians using cut-point-free metrics. Our results suggest that new analytical approaches could overcome cut-point limitations when studying the oldest-old. Future studies using these new cut-point-free PA metrics are warranted to provide more complete and comparable information across groups and populations.

Physical Activity, Physical Fitness And Adiposity; Associations With Cardiometabolic Health And Cognitive Function Across Adolescence.

The cross-sectional associations between physical activity, fitness, and adiposity with risk factors for cardiometabolic disease (particularly novel ones such as inflammatory cytokines) and cognitive function across the period of adolescence are not well understood. Additionally, novel physical activity metrics that summarise activity volume and intensity in a continuous manner have not been investigated in this context. PURPOSE: This study investigated the cross-sectional associations between physical activity, fitness, and adiposity with risk factors for cardiometabolic disease and cognitive function. These associations were compared between younger and older adolescents. METHODS: Seventy younger (11-12y, 35 girls) and 43 older (14-15y, 27 girls) adolescents volunteered to take part in the study. Fitness (multi-stage fitness test, MSFT) and adiposity (waist circumference) were determined; followed 7d later by resting blood pressure, a fasted blood sample (glucose, plasma insulin, IL6, IL10, IL15 and IL-1β concentrations) and a cognitive function test battery. Habitual physical activity was monitored via hip-worn accelerometers over this 7-d period and the average acceleration (activity volume), and intensity gradient (intensity distribution of activity) were determined. RESULTS: Average acceleration and intensity gradient were negatively associated with mean arterial blood pressure (β = -0.75 mmHg, p = 0.021; β = -10 mmHg, p = 0.006), and waist circumference was positively associated with IL-6 concentration (β = 0.03%, p = 0.026), with stronger associations observed in older adolescents. Higher fitness (MSFT distance) was positively associated with anti-inflammatory IL-15 concentration (β = 0.03%, p = 0.038) and faster response times on the incongruent Stroop task (β = -1.43 ms, p = 0.025), one-item Sternberg paradigm (β = -0.66 ms, p = 0.026) and the simple (β = 0.43 ms, p = 0.032) and complex (β = -2.43 ms, p = 0.020) levels of the visual search test, in the sample overall. CONCLUSIONS: The present study highlights the important role of physical activity (both the volume and intensity distribution) and fitness for cardio-metabolic health. Furthermore, the present study highlights the importance of fitness for a variety of cognitive function domains in adolescents, irrespective of age.

Upper Body Muscle Activation And Measures Of Sprint Performance

PURPOSE: Effective arm swing and core muscle activation are involved in acceleration and maximal sprinting, yet muscle activity in these areas have not been measured via electromyography (EMG) during over ground sprinting trials. The purpose of this study was to explore the relationship between muscle activation of the upper body and measures of performance during sprint acceleration and maximal sprinting. METHODS: Sixteen participants (20.93 ± 0.96 yrs.; 1.71 ± 0.07 m; 67.69 ± 11.81 kg) completed six 40-m sprint trials on an outdoor track, with three from a block start and three from a split start. Muscle activation was measured via EMG in the triceps brachii, biceps brachii, upper trapezius, anterior deltoid, latissimus dorsi, erector spinae, rectus abdominis, and oblique muscles, recorded as a percentage of maximal voluntary isometric contraction. Split times recorded during each sprint were used to calculate acceleration, net horizontal force (Fh), and the ratio of Fh and resultant ground reaction force (%RF) using previously validated methods. Repeated measures multilevel modeling was used to evaluate the relationship between mean upper body muscle activation and average acceleration, Fh, and %RF during each 10-m window of the sprint. RESULTS: During the 0-10 m window, mean activation of the upper trapezius showed a significant positive relationship with acceleration (t = 2.66, p = 0.01), Fh (t = 2.20, p = 0.03), and %RF (t = 2.57, p = 0.01), erector spinae activation was positively associated with %RF (t = 2.42, p = 0.02), and biceps activation was negatively associated with Fh (t = -2.23, p = 0.03). In the 30-40 m window, there was a significant negative relationship between mean latissimus dorsi activation and %RF (t = -2.16, p = 0.04). There were no significant relationships between upper body muscle activation and indicators of sprint performance detected during the 10-20 m or 20-30 m windows. CONCLUSIONS: These results indicate that upper trapezius muscle activity is important during initial sprint acceleration, which agrees with past research on scapular restriction limiting maximal acceleration while sprinting. After the initial period of sprint acceleration, there was no evidence that greater activation of certain upper body muscles was related to improving maximal sprinting performance.

Probabilistic Seismic Hazard Analysis of San José de Cúcuta, Colombia

This work evaluated the probabilistic seismic hazard of San José de Cúcuta (Colombia) using the methodology developed by Hanks and Cornell. Seismic hazard curves were obtained using a set of ground movement prediction equation which relate the average annual rate of earthquake exceedance against maximum acceleration values, assuming that the occurrence of the events presented in the area within the time period analyzed follows a Poisson´s distribution. Additionally, the average maximum acceleration values were calculated for a set of return periods, which were compared against the effective peak ground acceleration value for the city established in the current anti-seismic design code in Colombia. For the return period of 475 years, maximum acceleration values greater than those defined in the regulation were obtained with two of the soil movement prediction equations. With the results obtained, the level of high seismic threat in which the city is located has been corroborated and it is proposed to increase the maximum horizontal acceleration for anti-seismic design code from 0.35g to 0.40g.

Toxic effects of glyphosate on the intestine, liver, brain of carp and on epithelioma papulosum cyprinid cells: Evidence from in vivo and in vitro research.

Glyphosate (GLY) is the most widely used organophosphorus herbicide in agriculture. The present study aimed to analyze the comprehensive toxicological effects of GLY on juvenile common carp and an epithelioma papulosum cyprinid (EPC) cell line. In the in vivo experiments, exposure to GLY (5 and 15mg/L) for 30 days induced liver inflammation and oxidative damage in common carp and changed the physical barrier of the intestine. Histopathological analysis of the intestine, liver, brain, and changes in oxidative stress biomarkers provided evidence of damage and immune system responses to GLY. Moreover, an inhibitory effect of 15mg/L GLY on acetylcholinesterase (AChE) activity was found in the brain, which may be an important reason for the significant decrease in both swimming distance and average acceleration of common carp. Cell experiments showed that 0.65 and 3.25mg/L GLY inhibited the viability of EPCs. Furthermore, oxidative DNA damage, mitochondrial dysfunction, and reactive oxygen species (ROS) production were observed in EPC cells following GLY exposure. Taken together, this study not only highlights the negative effects of GLY on common carp but also enriches the knowledge of the cytotoxicity mechanism to further clarify the comprehensive toxicity of GLY in common carp.

Application of Newton’s laws using CD hovercraft

Hovercrafts were constructed using a Compact Disk and Baloons to calculate linear and average displacement, speed and acceleration. The innovative concepts was used to promote learning of Astrophysics to 15 aspiring physics enthusiast to explain the Newton’s laws of Physics as it applies to the working principle of an hovercraft and training of astronauts

Flight Demonstration of Pulse Detonation Engine Using Sounding Rocket S-520-31 in Space

A detonation engine system is successfully demonstrated for the first time in space using sounding rocket S-520-31 of the Japan Aerospace Exploration Agency/Institute of Space Astronautical Science. Detailed flight results of an S-shaped pulse detonation engine (PDE) installed in the rocket are presented herein. The flight is conducted to confirm that the PDE and its system operate at scheduled sequences in space, confirm the reproducibility of the PDE cycle, and despin the rocket around its axis. It is confirmed that the PDE operated successfully for 14 cycles in space. The experimental plateau pressure of is of the calculated plateau pressure, which suggests that detonation occurred in 14 cycles. The pressure profiles of the cycles are similar, and the pressure integrals are , confirming the excellent reproducibility of the PDE cycle. A probability statistical approach assuming a Gaussian distribution is applied to determine the average angular acceleration difference between processes of the PDE operation, mixture supply, and oxygen supply. The results suggested that the PDE despun the rocket via the thrust produced via detonation combustion, which is consistent with a quasi-steady-state model with an accuracy of .

The effect of mandibular movement on temporomandibular joint morphology while eating French fries

BackgroundThe preferred masticatory side was reported to be almost always the same as the affected side of the temporomandibular disorder. Unbalanced alterations of temporomandibular joint morphology were found to be associated with unilaterally masticatory habits. The aim of this study was to investigate the effect of the mandibular movement on the remodeling of temporomandibular joint during eating French fries using a 3D motion capture system. MethodsTwelve volunteers with non-maxillofacial deformity and a healthy temporomandibular joint were recruited. The 3D models of the mandible and the maxilla were reconstructed according to computed tomography. The subjects were asked to eat French fries by unilaterally mastication, which was recorded by a 3D motion capture system. The trajectories of the incisors and the condyles and the condylar acceleration during unilateral mastication were analyzed. ResultsDuring incisal biting, there was no significant difference in the condylar trajectories between the left and right sides (P > 0.05). During unilateral mastication, the average displacement and acceleration of the masticatory condyles were significantly lower than those of the non-masticatory condyles (P < 0.05). The trajectory angles of the masticatory condyles were significantly steeper than those of the non-masticatory condyle (P < 0.05). During swallowing, there was no obvious movement of the mandible. ConclusionsBetween both temporomandibular joints, unilateral mastication resulted in significant differences in the regions of the condylar movement within the articular fossa, and then caused different compressive regions of the temporomandibular joints. Thus, unilateral mastication might result in a significantly different pattern of temporomandibular joint remodeling between the two sides.

Sudden Slide Mechanism of a Rock Block in Road Cutting Slope with Soft and Hard Interlayered Bedding Structure Based on Energy Balance Theory

After the road excavation of the hard and soft interlayered bedding slope in the mountainous region's valley area, the bedding slope often results in a catastrophic phenomenon, especially in the project's construction and operation where existed severe safety hazards. A geomechanical two-component model consisting of the slider and the underlying layer is proposed to analyze the rock block instability under the fissure water pressure, the shear deformation, and the compression deformation. The slider's complex stress field is derived by using elastic mechanics. The incremental energy equilibrium Equation is established based on the energy balance theory, and the generalized sliding force relative function of the slider and the generalized shear force relative function of the underlying soft rock are obtained. The deformation energy accumulation, transfer, and energy dissipation characteristics are analyzed. Put a rock slide in the bedding rock cutting slope happened at Jiaojiatan, Pengshui County, Chongqing municipality, China as a case. Results indicate that considering both the compression deformation and the shear deformation of the slider, the kinetic energy, the rapid launch speed of the projectile, the average projectile acceleration, and the failure stroke increase about 15.7 times, 4.0 times, 1.8 times, and 8.9 times respectively than that of only considering the shear deformation, and the dynamic disaster intensity is more severe and worthy of attention. The results that ignored the fissure water pressure and the compressive deformation energy coincide with the existing literature, which verifies the reasonable applied method in this paper. Considering the slider's different displacements and the height-length ratios, when the energy ratio function that represents the ratio of the incremental compression energy to the incremental shear energy concludes that when the range of the height-length ratio is between 0 to 0.95(flat and narrow sliders), the compression energy's contribution to the system's elastic energy should be taken into consideration. The advantage of the energy balance method applied in the stability analysis of the bedding rock slope is that the potential unstable rock block's status can be predicted dynamically according to the variation of the underlying soft rock's deformation and that the elastic impact dynamic parameters can also be obtained compared with other instability analysis approach.

Addressing unobserved heterogeneity at road user level for the analysis of conflict risk at tunnel toll plaza: A correlated grouped random parameters logit approach with heterogeneity in means

Toll plaza is a designated area of controlled-access roads like expressway, bridge, and tunnel for toll collection. A number of toll booths are often placed at the toll plaza accommodating high passing traffic and multiple payment methods. Traffic and safety characteristics of toll plazas are different from that of other road entities. Different conflict risk indicators, which are usually longitudinal, have been adopted for real-time safety assessment. In this study, correlated grouped random parameter logit models with heterogeneity in the means are established to capture the unobserved heterogeneity, with additional flexibility, at road user level for the association between conflict risk and influencing factors. In addition, modified conflict risk indicator is developed to assess the safety of diverging, merging, and weaving movements of traffic, with which vehicles’ dimensions (width and length), and longitudinal and angular movements are considered. Also, prevalence and severity of both rear-end and sideswipe conflicts are assessed. Results indicate that toll collection type, vehicle’s location, average longitudinal speed, angular speed, acceleration, and vehicle class all affect the risk of traffic conflicts. Furthermore, there are significant correlation among the random parameters of severe traffic conflicts. Proposed analytic method can accommodate the conflict risk analysis for different conflict types and account for the correlation of unobserved heterogeneity. Findings should shed light on appropriate remedial measures like traffic signs, road markings, and advanced traffic management system that can improve the safety at tunnel toll plazas.

Evaluation of Big Data Analytics and Cognitive Computing in Smart Health Systems

The current era of Big Data has led to the use of advanced AI programs that can learn from individual data points, providing intelligent feedback in real time. Their ability to learn and grow more complex is particularly important when they are applied to smart health systems. These systems carry out an analysis of patient data through the use of machine learning and deep learning methods with customizable models designed using the latest advancements in artificial intelligence software. Furthermore, Big Data Analytics has also allowed for a new form of computational intelligence, which is cognitive computing. Experimental results: the average query performance acceleration ratio of the designed complex network big data overlapping information detection method and the other two detection methods is 11.585, 17.411 and 17.642, which proves that the detection method integrates the advantages of cloud computing platform has a higher performance.

Magnetostrictive biomechanical energy harvester with a hybrid force amplifier

Vibrating energy harvesters, capable of converting mechanical energy into electrical energy, have attracted unprecedented interest in both academia and industry because of their great potential for harvesting energy induced by human activity and energy around the body, and to drive low-power wearable biosensors and electronics, micro-robots, and implantable biomedical devices. In this paper, based on the magnetostrictive inverse effect, we propose a magnetostrictive vibration harvester using Terfenol-D, which generates electrical energy when subjected to human movement. A hybrid force amplification frame is integrated in this harvester to amplify weak biological movements. The detailed mathematical model of the multi-stage force amplification process is established, the hybrid force amplifier is also designed in detail, and its structural dimensions are optimized. The position and form of the bias magnetic field arrangement based on the Terfenol-D harvester is systematically analyzed. The experiment shows that 4.13 V peak voltage and 426.4 mW peak power are generated when the harvester is fully compressed. The output power is 213.16 mW and 371.43 mW at an average acceleration of 2.5 g for slow walking and 4 g for jogging, respectively. The results of this study suggest that the combination of rod Terfenol-D and force amplification mechanisms can be used to design bio-vibrational energy harvester with excellent performance, which is especially suitable for self-powered wearable electronic devices.

PERBEDAAN PENGOLAHAN COOKIES KURMA OVEN DAN KUKUS TERHADAP PERCEPATAN PERSALINAN KALA II

Long parturition is one of the causes of maternal and fetal death. By consuming dates before delivery, besides being filling, it is also useful for making the uterine contractions more regular. The purpose of the study was to compare the processing of oven date Cookies and steamed date Cookies to the acceleration of the second stage of labor at BPM Az Jambi City in 2021. This research is a pre-experimental study with two posttest groups. This research was carried out at BPM Azimah Jambi City in July 2021. The population in this study were all mothers who gave birth at BPM Azimah in july-august 2021. The sample of this study used purposive sampling technique. Data collection was carried out by processing and giving oven date Cookies and steamed date Cookies to the second stage of labor and assessing the acceleration of labor. The analysis used is univariate and bivariate. The results showed that the average acceleration of labor in the second stage given oven Cookies was 26.8 minutes, while the average description for the second stage of labor given steamed Cookies was 30.6 minutes. There is no difference in the average acceleration of labor in the second stage of processing oven and steamed date Cookies at BPM A Jambi City in 2021 with a p value of 0.559. It can be concluded that giving oven date Cookies and steamed date Cookies has no difference on the progress of labor. The results of this study can be used as a reference for midwives in providing delivery care in order to meet nutritional intake and hydration during childbirth in helping the progress of labor. &lt;br /&gt;Bibliography : 30 (2010-2019) Keywords : Oven Date Cookies, Steamed Date Cookies, Labor Acceleration

Structural decomposition-based energy consumption modeling of robot laser processing systems and energy-efficient analysis

• Generalized motion EC models of main functional units of the RLPS were established, while the computational complexity of EC was analysed. • A structural decomposition and modeling method of EC was proposed for the IR, to achieve rapid EC calculation of IRs. • The energy-saving planning problems were analyzed for a laser processing IR welding complex parts. Energy efficiency has been one of the main issues in manufacturing. Rapid energy consumption (EC) calculation is the key to improving the efficiency of EC optimization. In this paper, rapid EC calculation of robot laser processing systems (RLPSs) is studied based on structural decomposition. Firstly, the generalized motion EC models of main functional units of RLPSs are established for manufacturing processes, while the power consumption characteristics and computational complexity of EC are analyzed. Then, a modeling method of EC is proposed for industrial robots (IRs), based on structural decomposition, considering the generating mechanisms and computational complexity of EC. The models of all EC components are established, which are all parameterized functions of time or key factors (joint angle paths of the robot and the average acceleration of the end-effector). Moreover, EC models of other functional units are also well established according to the corresponding EC characteristics. A KUKA robot case is described to verify the proposed method. The results show that the established EC model of the IR has reliable prediction accuracy within the feasible speed range, which can well reflect the characteristic relationships between EC and time. The proposed study solution is also suitable for EC modeling of other robot manufacturing systems. Furthermore, the energy-saving planning of processing complex parts are analyzed for a laser processing IR. The RLPS has considerable energy-saving potentials under situations concerned.

Thin-shell effects on nonlinear bubble evolution in the ablative Rayleigh–Taylor instability

The influence of thin-shell effects on the nonlinear evolution of two-dimensional single-mode ablative Rayleigh–Taylor instability (ARTI) is studied in the parameter range of inertial confinement fusion implosions. A new phase of unsaturated nonlinear bubble evolution caused by thin-shell effects is found. This is different from the traditional opinion that the bubble velocity becomes saturated after the ARTI evolution enters a highly nonlinear regime. A modified bubble velocity formula is proposed, based on the Betti–Sanz model [Betti and Sanz, Phys. Rev. Lett. 97, 205002 (2006)], considering the thin-shell effects. It is shown that the bubble velocity becomes saturated in the thick-target case after the ARTI evolution enters a highly nonlinear regime. In this case, the Betti–Sanz bubble dynamics model can predict the evolution of bubble velocity. However, when the thin-shell effects become significant in the case of kD0 &amp;lt; 100, where D0 is the initial thickness of the target and k is the perturbation wavenumber, the difference of the average acceleration between the bubble vertex and the spike tip can be much more significant than that of the thick-target case. In this situation, the nonlinear evolution of the ARTI bubbles will accelerate without saturation until the target breakup, which cannot be depicted by the Betti–Sanz model while the improved theory formula is applicative. The Betti–Sanz model and the improved theory formula are independent of the initial perturbation amplitude.

CALIBRATION TEST RESULT ACCELEROMETER SENSOR

MEMS sensors commonly used in various studies for cost efficiency in production and well produced in large quantities. Sensor calibrate was important because of large quantities product and ensure that product can be operate proper and the output based on standard production. The ADXL345 sensor calibration test is carried out by measuring the output acceleration on a combination of 3 axes X, Y, and Z, name d X+ (X axis gets a positive gravitational acceleration of 1 g), X (X axis gets a negative gravitational acceleration of 1 g), Y+, Y - , Z+, and Z-. A total of 100 data were collected and 10 data were presented in tables in each condition and presented in graphical form. ZeroG offset testing on the X-axis and Y-axis is carried out in the Z+ condition because in this condition the X-axis and Y-axis get a natural acceleration of Earth's gravity of 0 g. In this condition, the acceleration value on the Z axis is 0.9074g . For the X axis is -0.0048 g and -0.0778 g for the Y axis. This value is obtained from the average acceleration value of the X axis and Y axis in the Z+ condition. The zeroG offset test on the Z axis is determined by taking the middle value of the average measurement results in the Z+ and Z- conditions. This value is not the same as the typical value in the datasheet of 0 g, but the 0g offset value of these three axes is still within the minimum range of the sensor datasheet. The sensitivity value of the sensor in the calibration test results has a tendency to differ on each axis. The X-axis of 4.0012 mg/LSB maximum range, Y-axis of 3.9900 mg/LSB close to the values on the data sheet, and Z-axis of 3.7403 mg/LSB near the range of values