Sistem Pendeteksi Kecelakaan Kendaraan Bermotor Menggunakan Arduino Dan Smartphone Android

- Many motor vehicle accidents occur in Indonesia. One of the factors causing the high number of accidents is the large number of motorized vehicle users. Accident reporting is currently still hampered by reporting. This research creates an accident reporting system that is fast and automatic to a web server. This study aims to create a system that can report accident locations. Next, the preparation of the machine condition status detection device. And the web server receives the coordinates of the crash site. This system combines an android smart phone with an Arduino microcontroller. In this research, the voltage sensor is used to overcome the motor vehicle battery voltage. Machine condition data transmission status from device to android smart phone using bluetooth HC-05. Accelerometer and GPS sensors on android smartphones are used to check acceleration and location coordinates during an accident. This study uses 4 vehicle conditions while moving. Vehicle traveling normally, sudden brake, front collision and side collision. The speed limit value used in this study is 19.04 m / s2 or 1.94 g. Based on the research results, when the vehicle is running normally there is no significant change in the value of acceleration. In a sudden brake condition, the Y axis of the acceleration sensor decreases in value until the acceleration value is negative. In the hit-front condition, the Y-axis value has increased significantly. Meanwhile, in a side hit condition, the value of the X and Y axes has increased significantly. The front and side crash conditions were tested 10 times each. Front hit conditions were identified as accidents by 80%. While the side hit condition was identified as an accident as much as 100%. Keywords: sensor, accelerometer, accident, GPS, Android smart phone.

Atmospheric Responses to Kuroshio SST Front in the East China Sea under Different Prevailing Winds in Winter and Spring

Atmospheric responses to the Kuroshio SST front in the East China Sea under different prevailing winds are examined using high-resolution observations and numerical modeling. Satellite data reveal a significant in-phase relationship between SST and surface wind speed, indicative of ocean-to-atmosphere influence. The atmospheric response varies according to the relative surface wind direction with respect to the SST front orientation. Under the alongfront condition, low (high) SLP anomalies are found on the warmer (colder) flank of the front, accompanied by surface wind convergence (divergence). Enhanced precipitation and frequent cumulus convection appear over the warm Kuroshio, suggesting an atmospheric response extending into the free troposphere. Under the cross-front condition, when the air blows from cold to warm (warm to cold) SST, divergence (convergence) is located directly over the SST front, and its magnitude is proportional to the downwind SST gradient. Under such prevailing winds, the SST front has little effect on the SLP and precipitation. The Weather Research and Forecasting (WRF) Model is used to investigate the mechanism responsible for the atmospheric adjustment. The results show that under the alongfront condition, large temperature and pressure perturbations in the boundary layer are caused by SST gradients, while stability and turbulent mixing are less affected. By contrast, under the cross-front condition, the perturbations of temperature and pressure are small and shifted downstream, while the SST gradient exerts stronger impact on vertical mixing. The modeling results confirm that the pressure adjustment mechanism contributes more to the atmospheric response under alongfront prevailing winds, while the vertical mixing mechanism dominates the atmospheric adjustment under cross-front winds.

On Non-Boussinesq Gravity Currents in Non-Rectangular Cross-Section Channels

We consider the propagation of a gravity current of density ρc from a lock length x0 and height h0 into an ambient fluid of density ρa in a horizontal channel of height H along the horizontal coordinate x. The bottom and top of the channel are at z = 0, H, and the cross-section is given by the quite general −f1(z) ≤ y ≤ f2(z) for 0 ≤ z ≤ H. When the Reynolds number is large, the resulting flow is governed by the parameters R = ρc/ρa, H* = H/h0 and f(z) = f1(z) + f2(z). We show that the shallow-water one-layer model, combined with a Benjamin-type front condition, provides a versatile formulation for the thickness h and speed u of the current. The results cover in a continuous manner the range of light ρc/ρa ≪ 1, Boussinesq ρc/ρa ≈ 1 and heavy ρc/ρa ≫ 1 currents in a fairly wide range of depth ratio in various cross-section geometries. We obtain analytical solutions for the initial dam-break stage of propagation with constant speed, which appears for any cross-section geometry, and derive explicitly the trend for small and large values of the governing parameters. For large time, t, a self-similar propagation is feasible for f(z) = bzα cross-sections only, with t(2+2α)/(3+2α). The present approach is a significant generalization of the classical non-Boussinesq gravity current problem. The classical formulation for a rectangular (or laterally unbounded) channel is now just a particular case, f(z) = const., in the wide domain of cross-sections covered by this new model.

DIFFERENCES IN KNEE JOINT KINEMATICS AND KINETICS DURING LEVEL WALKING AND WALKING WITH TWO TYPES OF POLES — FOCUS ON KNEE VARUS MOMENT

Walking with poles is one of the gait modification strategies for reducing external knee varus moments in people with medial knee osteoarthritis (OA). However, there are two types of pole techniques, Nordic walking (NW: pole back condition) and pole walking (PW: pole front condition). The purpose of this study was to investigate the differences in knee joint kinematics, and kinetics during level walking, and two types of walking with poles. A total of 22 subjects with a mean age of 21.2 years (SD: 1.3 years) participated. Three-dimensional gait analysis was conducted on level walking (LW), NW and PW. The first and second peaks of the knee kinematic and kinetic data and ground reaction forces were used. No significant differences were found between NW and PW in the knee kinematics and kinetics data. The second peak of the knee varus moment in NW and PW (0.34 and 0.33 Nm/kg, respectively) was significantly decreased compared to LW (0.42 Nm/kg, p < 0.01; Effect size = 0.70, p < 0.01; Effect size = 0.82). The first peak of the flexion moment in the knee during NW (1.2 Nm/kg) was significantly higher compared to LW (1.2 Nm/kg, p < 0.01; Effect size = 0.98). However, the present study could not clarify any different effect on the knee joint due to different instructions of the back pole and forward pole technique.

The effects of model upper limb position on observer P300 event-related potential

Summary Study aim: This study reports on the characteristics of learners’ information-gathering processes when receiving visual motor information by examining the influence of differences in model upper limb placement on observer attention. Materials and Methods: The experiment, which was conducted with seven subjects, consisted of a visual oddball task in which subjects were instructed to push a button corresponding to the target image when it was presented on a screen. Two images were used in the task: a “front” image in which the upper limbs were placed in front of the trunk, and an “outside” image in which the upper limbs were placed outside the trunk. The variables measured were brainwaves during task performance, button push reaction time, and questionnaire responses. Brainwaves were recorded at the Fz, Cz, and Pz electrode sites and event-related potentials at the time of target image presentation were calculated. Grand mean waveforms and mean potentials were also compared for the P300. Results: Comparisons of P300 amplification grand mean waveforms and mean potentials revealed that amplification was greater in the front condition than in the outside condition. Conclusion: This finding indicates that differences in model upper limb placement greatly affect observer attention.

A general description of a gravity current front propagating in a two-layer stratified fluid

The behaviour of a gravity current propagating into a two-layer stratified ambient fluid is described in detail. A comprehensive description is given of the different flow regimes, with particular emphasis on the front condition linking the thickness of the gravity current to its speed of propagation and the transfer of energy to upstream disturbances in the form of internal bores and nonlinear solitary waves. Hydraulic theory analogous to that of two-layer flow over topography (Baines, J. Fluid Mech., vol. 146, 1984, pp. 127–167) is extended to the gravity current problem to classify frontal behaviour into the following regimes: Type I, subcritical currents; Type II, currents that generate upstream undular bores; Type III, currents that generate an upstream monotonic bore connected by a rarefaction; Type IV, supercritical fronts with a large-amplitude trapped solitary-wave-like disturbance; and Type V, supercritical gravity currents. Over 200 two-dimensional Boussinesq–Euler simulations spanning a range of gravity current properties demonstrate good agreement, for both the behavioural regime and the front condition ${U}_{o} (h)$, with hydraulic theory that extends original work by Rottman & Simpson (Q. J. R. Meteorol. Soc., vol. 115, 1989, pp. 941–963) to arbitrary ambient layer thickness, and uses an improved closure for the upstream bore that correctly predicts the behaviour in the limit of large bore amplitude. In addition, the energy balance is analysed, and it is shown that the energy transfer from the gravity current to upstream disturbances is significant, and consistent with the hydraulic theory. The results demonstrate a clear connection to the problem of upstream resonance in two-layer flow over topography, and have significant implications for interpreting field observations of nonlinear internal waves generated by atmospheric density currents and coastal river plumes.