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Bridges with high piers exceeding 40 m are generally monoliths between girder and pier to accommodate lateral deformations and obtain high stiffness to achieve adequate elevation of the piers during an earthquake. This monolith PCI girder bridge was designed and built before the SNI 2833:2016 bridge earthquake regulation was issued. The bridge is supported by abutments and three tall piers with height of piers is 42.81 m to 46,451 m and consists of four PCI girder monolith spans with a length of each span of 35m+35m+35m+40m. The bridge structure is modeled using the finite element method. The piers and beams of the bridge are modeled as frame elements, and the deck as shell elements. The abutments are assumed to be joint supports and the pier legs are assumed to be fully clamped. The relationship between the girder and the head of piers is defined as a rigid link while the head of piers and the pier legs is defined as an elastic link of rigid type. This bridge is located in a strong earthquake area and has high piers so a more complex analysis is needed to predict the performance of the bridge structure by applying a nonlinear time history analysis using Elcentro earthquake. The observed structural responses are displacement, velocity, acceleration, and drift ratio at top of the piers P1, P2 and P3. The results show that the displacement is more dominant in the longitudinal direction of the bridge. The speed of both the longitudinal and transverse directions did not have a significant difference, while the acceleration of the bridge in the transverse direction was greater than longitudinal direction. Referring to the parameters given by NCHRP 440, the drift ratio is less than 1% so that the performance level of the PCI girder monolith bridge structure is included in the operational category. [ABSTRACT FROM AUTHOR]

An Optical Imaging Electro-System (OIES) is an equipment used to capture images from a long range in the form of electromagnetic radiations and convert them into electrical signals which are then transferred to a system where these signals are converted for visual display. These systems are always operated in an environment exposed to wind gust, shocks, earthquakes, etc. The optical systems are sensitive to these effects and the equipment housing the system must tolerate these effects. In the present work, study is carried out on dynamic behavior such as Modal, Harmonic and Shock analysis of the external body which houses the OIES. Several iterations are carried out by making changes in geometry (varying thickness, inclusion of stiffeners, etc.) and material (Aluminium 2024, Aluminium 7075 and Titanium alloy). The CAD models are developed using ANSYS SPACECLAIM and analysis was carried out using ANSYS workbench software. Natural frequencies of the system are obtained from modal analysis and are used for harmonic and shock analysis. Natural Frequencies obtained for mode 1 to mode 10 are in the range of 69 Hz to 313 Hz for different models. In harmonic analysis, the deformation, stress and acceleration response of the frequencies are studied. From Harmonic analysis, deformation in X axis is found to be 1.71 mm to 6.75 mm, stress of 1.33 MPa to 26.36 MPa for different models. In Shock analysis, the behavior of the natural frequencies is studied under the influence of shock loads. The model that is best suited for the operation is selected by considering all the factors. [ABSTRACT FROM AUTHOR]

Convolutional neural networks (CNNs) play an important role in today's mobile and edge computing systems for vision-based tasks like object classification and detection. However, state-of-the-art methods on CNN acceleration are trapped in either limited practical latency speed-up on general computing platforms or latency speed-up with severe accuracy loss. In this paper, we propose a spatial-based dynamic CNN acceleration framework, NeuLens, for mobile and edge platforms. Specially, we design a novel dynamic inference mechanism, assemble region-aware convolution (ARAC) supernet, that peels off redundant operations inside CNN models as many as possible based on spatial redundancy and channel slicing. In ARAC supernet, the CNN inference flow is split into multiple independent micro-flows, and the computational cost of each can be autonomously adjusted based on its tiled-input content and application requirements. These micro-flows can be loaded into hardware like GPUs as single models. Consequently, its operation reduction can be well translated into latency speed-up and is compatible with hardware-level accelerations. Moreover, the inference accuracy can be well preserved by identifying critical regions on images and processing them in the original resolution with large micro-flow. Based on our evaluation, NeuLens outperforms baseline methods by up to 58% latency reduction with the same accuracy and by up to 67.9% accuracy improvement under the same latency/memory constraints. [ABSTRACT FROM AUTHOR]

Monitoring physical fatigue and capacity is important in high-performance environments to optimize the training stimulus and minimize unplanned physical fatigue. For that purpose, accelerometer sensors have emerged as a tool with the potential to measure and reflect changes in runner's acceleration. An accelerometer was used to measure the acceleration patterns which provided an analogue signal that could analyzed further by using different feature extractions. This research was aimed to estimate the location of physical fatigue occurrence in 400 m running. Basically, the experiments were conducted in outdoor track field, 6 subjects were involved, with age ranging between 19-24 years. In this study, two features have been used which are root mean square (RMS) and player load (PL) to indicate fatigue. The obtained results have shown that there were declines in the player load values in the last 150 m of running for most of the subjects which indicate occurrence of physical fatigue. On the other hand, some subjects have tried to save their energy in the 2nd and 3rd 100 m to speed up again in the last 100 m but there were obvious decrements in their player load in 400 m compared to the 1 100 m of running. [ABSTRACT FROM AUTHOR]

A specific operating mode was observed for Hall thrusters in the power range up to 5 kW when at least one of the following changes occurred: a decrease in gas flow rate, an increase in magnetic field magnitude, an extension of ceramics or a change in ceramics properties. The thruster operating in the observed mode has total efficiency from 5 to 20% lower than in the design mode. In this paper, relative erosion rate of boron nitride (BN) ceramics was measured for a Hall thruster with external ionization and acceleration region for both operating modes using passive spectral analysis. The Hall thruster has middle line diameter of 77mm and maximum power up to 2.5 kW. Estimations of the relative erosion rate were based on boron doublet linewith wavelengths of 249.677 and 249.773 nm. During the study, discharge voltage range was from 400 to 1000 V, mas flow rate range was from 2 to 6 mg/s. It was shown that the relative erosion rate for all operating conditions is lower for the operating mode with lower efficiency for chosen thruster. [ABSTRACT FROM AUTHOR]

Falls of elderly people are a major public health issue. For the victims and their surroundings, the resulting health expenses can be a heavy burden, largely because of the long recovery periods and the potential of co-morbidities that arise. Research efforts in fall detection have produced a wide range of solutions. These are classified as wearable and non-wearable systems. Fall detection algorithms running on these systems are being tested by young volunteers inside lab environment taking out the impact of real-life scenarios and real elderly people. Unlike other algorithms that use three-axial acceleration and angular velocity to detect a fall, our algorithm uses one single axis. The algorithm was validated with 8 elderly aging above 65 years and with either a minor walking disorder or coping from either fear of fall or previous fall injuries. Results showed 99% sensitivity and 94.8% specificity. The system has a registered accuracy of 97.5%. [ABSTRACT FROM AUTHOR]

Characteristic points of the law of motion were determined based on the results of experimental study on the velocities and accelerations of the lifted barbell. Relationship between the height of the athlete, lifted weight, maximal velocity and acceleration was estimated analytically. It was shown, that at the initial time moment the athlete must apply approximately 1,5 times larger force than lifted weight. The values of the parameters of the barbell' law of motion and lifting force approximate law of change were estimated. [ABSTRACT FROM AUTHOR]

The transmission of mechanical vibrations from tools to human subjects is known to be potentially dangerous for the circulatory and neurological systems. It is also known that such damages are strictly depending on the intensity and the frequency range of the vibrational signals transferred to the different anatomical districts. In this paper, very high impulsive signals, generated during a shooting by a rifle, will be studied, being such signals characterised by a very high acceleration amplitude as well as high frequency range. In this paper, it will be presented an experimental setup aimed to collect experimental data relative to the transmission of the vibration signals from the rifle to the shoulder of subject during the shooting action. In particular the transmissibility of acceleration signals, as well as of the velocity signals, between the rifle stock and the subject's back shoulder will be measured using two piezoelectric accelerometers and a single point laser Doppler vibrometer (LDV). Tests have been carried out in a shooting lab where a professional shooter has conducted the experiments, using different experimental configurations: two different types of stocks and two kinds of bullets with different weights were considered. Two uniaxial accelerometers were fixed on the stock of the weapon and on the back of the shoulder of the shooter respectively. Vibration from the back shoulder was also measured by means of a LDV simultaneously. A comparison of the measured results will be presented and the pros and cons of the use of contact and non-contact transducers will be discussed taking into account the possible sources of the measurement uncertainty as unwanted sensor vibrations for the accelerometer. [ABSTRACT FROM AUTHOR]

In this paper the influence of body acceleration on the flow of blood through a stenosed catheterized artery is studied. The effect of non-Newtonian nature of blood in small blood vessels has been taken into account by modeling blood as Casson fluid. The governing equations of the fluid flow are solved using the perturbation technique, assuming the Wormsely number as small. The effect of catheterization, height of the stenosis, body acceleration on the flow shear stress and resistance to flow are studied. [ABSTRACT FROM AUTHOR]

The purpose of this study was to examine the validity of a commercially-available accelerometer, as used in the field team sports context. Ten adult participants completed two movement tasks: 1) a drop landing task from 30-cm, 40-cm and 50-cm heights [DLAND], and 2) a countermovement jumping task [CMJ]. Peak acceleration values, both smoothed and unsmoothed, occurring in the longitudinal axis [Y] and calculated to produce vector magnitude values [VM], were compared to peak vertical ground reaction force values [VGRF]. All acceleration measures were moderately correlated (r = 0.45 - 0.70), but also significantly higher than weight-adjusted VGRF, for both tasks. Though the raw acceleration measures were mostly above the acceptable limit for error (> 20%), the smoothed data had reduced error margins by comparison, most of which were well below 20%. These results provide some support for the continued use of accelerometer data, particularly when smoothed, to accurately quantify impacts in the field. [ABSTRACT FROM AUTHOR]

The purpose of this study was to examine and describe effects of knee flexion angle, stance width and vibration platform frequency on the transmission of vertical acceleration about the knee. Fifteen adults were exposed to various vibration conditions while standing on a side-to-side vibration platform. Vertical acceleration data, expressed as transmission, were shown to be attenuated for all vibration conditions. A larger degree of knee flexion however, was conducive to greater attenuation about the knee. Such information may be used to develop vibration training programs with a more thorough understanding of effects of vibration. [ABSTRACT FROM AUTHOR]

Based on the conducted experiments for collection and processing the data for the acceleration of human body, analysis on the possibility for detection of unintended human falling has been carried out. The basis for the analysis an electronic system with a microcontroller has been proposed. In case of emergency, the information is transmitted to a centralized informational station. The system is attached to the human body, in the breast area. [ABSTRACT FROM AUTHOR]

The article focuses on a study on a comparison between three-dimensional (3D) accelerations recorded using accelerometers and a high speed motion capture system amid whole body vibration (WBV). Camera technology has benefited the study of the adverse impact of WBV on the skeleton but the technology is yet to be compared to the traditional accelerometer approach. Results show a disparity between the two approaches in terms of vertical measurements. Vertical tibial acceleration measurements have been found to be greater with the camera technology.

The article discusses a study which compares the vertical loading rates, vertical impact peak and peak positive acceleration between female runners who develop plantar fasciitis (PF) and runners who never had running injury (CON). It cites a hypothesis that the PF group will display higher vertical loading rates, vertical impact peaks and positive accelerations of the tibia as compared to the CON group. It suggests that runners with high vertical loading rates, impact peaks and PPA of the tibia while running are predisposed to develop plantar fasciitis.