Accuracy and quickness criterion-based driving skill metric for human adaptive mechatronics system

Previous studies on driving skill algorithm have combined tracking error and time related variables into algorithm formulation. This method however does not include a car orientation and lateral speed information as an integral part of the algorithm. Two new variables are introduced into the algorithm structure, namely, orientation angle and lateral speed. Nine participants were carefully recruited for a driving test to validate the algorithm. A simulated driving environment was specifically devised for this experiment. A driving track used in this experiment was segmented into five different severities for data analysis. Two fundamental goals have led to the collection and subsequent analysis of the data. The first is analysing the variables in relation to the driving task. The second involves data analysis being further extended into analysing the algorithm performance over estimating the driving skill index. The results reveal that the proposed variables are well correlated with the driving task, and improvement in algorithm performance is found to be almost double compared to the previous algorithm

A numerical simulation of vehicle dynamics behavior for a four-wheel steering vehicle with the passive control system

The Advanced Driver Assistance System (ADAS) is a technology in the vehicle to assist drivers in mitigating road risk and improving maneuverability. The system is capable of providing warnings to drivers and even executing an action if necessary. However, these systems are limited to the sensors and capability of the vehicle. Increasing the degree of freedom of a vehicle could potentially develop new ADAS with more efficiency. Along with the X-By-Wire technology, a four-wheel drive and independent steering (4WDIS) can be produced as a part of ADAS, especially for electric vehicles. In this research, an understanding of the steering characteristic of a 4WDIS during steady-state cornering (SSC) is presented using numerical simulation in MATLAB. An actual Segment B type vehicle is used as a simulation model and a preliminary two-wheel steering SSC simulation was performed to determine the steering characteristics. The model is modified to include a rear steer angle with a passive control system and the SSC simulation was repeated. The results show that the vehicle can perform SSC by increasing the yaw rate at high speed using the opposite steering mode. Meanwhile, parallel steering mode is suitable during low-speed cornering which can increase the yaw rate while maintaining stability

Change Detection Of Cropping Pattern In Paddy Field Using Multi Spectral Satellite Data For Estimating Irrigation Water Needed

This paper investigates the use of multi spectral satellite data for cropping pattern monitoring in paddy field. The southern coastal of Citarum watershed, West Java Province was selected as study sites. The analysis used in this study is identifying crop pattern based on growth stages of wetland paddy and other crops by investigating the characteristic of Normalized Difference Vegetation Indices (NDVI) and Wetness of Tasseled Cap Transformation (TCT) derived from 14 scenes of Landsat TM date 1988 to 2001. In general, the phenological of growth stages of wetland paddy can be used to distinguish with other seasonal crops. The research results indicate that multi spectral satellite data has a great potential for identification and monitoring cropping pattern in paddy field. Specific character of NDVI and Wetness also can produce a map of cropping pattern in paddy field that is useful to monitor agricultural land condition. The cropping pattern can also be used to estimate irrigation water needed of paddy field in the area. Expected implication of the information obtained from this analysis is useful for guidance more appropriate planning and better management of agricultural

Classical tests of general relativity in the Newtonian limit of Schwarzschild-de Sitter spacetime

Recently it has been shown that despite previous claims the cosmological constant affects light bending. In the present article we study light bending and the advance of Mercury's perihelion in the context of the Newtonian limit of Schwarzschild-de Sitter spacetime employing the special relativistic equivalence of mass and energy. In both cases, up to a constant factor, we find the same results as in the full general relativistic treatment of the same phenomena. These approximate and intuitive arguments demonstrate clearly what effects should have been expected from the presence of $\Lambda$ in the general relativistic treatment of these phenomena.Comment: 12 pages, Revtex, 1 figur

The influence of land-use land-cover changes on urban bird communities

City development changes the landscape and has been claimed to pose threat to the survival of birds that heavily relies on healthy forest ecosystem. As such, this study assessed the effect of land-use land-cover (LULC) changes due to sub-urbanisation on birds' community using geostatistical method. In this study, geostatistical analyses, namely Kernel Density and Ordinary Least Square (OLS), were executed to identify the dominant factors that affected the birds' community in the Johor Bahru region. The birding data were obtained from eBird, an online crowd source database of bird distribution. The distribution of bird community was analysed by using Kernel density for years 2016 and 2018. This study found that the hotspot locations of the birds were in Danga Bay and Kempas Denai for year 2016, whereas Kampung Pok, Bukit Chagar, Taman Sentosa and Kampung Dato Sulaiman Menteri for year 2018. Certain urban bird species increased from year 2016 to 2018. The OLS regression was applied to analyse the relationship between birds' occurrence and LULC features within the study area. The global regression model indicated that distance to forest and distance to recreational and open space were positively associated with the number of bird occurrence. On the contrary, distance to road was negatively associated with the number of bird occurrence. The OLS model for year 2016 between birds' occurrence and distance to road, distance to forest, as well as distance to recreational and open space, demonstrated an adjusted R2 value of 0.32. In year 2018, the correlation between birds' occurrence and distance to road, as well as distance to recreational and open space, demonstrated an adjusted R2 value of 0.11. As a conclusion, urbanisation seems to affect the birds' communities as it increases the number of urban birds spotted in Johor Bahru, which is attributed to the increasing recreational and open space areas in Johor Bahru. The study outcomes can be applied to comprehend the relationship between birds' community and LULC changes, as a result of urbanisation

THE QUALITY OF OPENSTREETMAP IN MALAYSIA: A PRELIMINARY ASSESSMENT

Over recent years, the phenomena, Web 2.0 has led to the growth of volunteered geographic information (VGI). The emergence of VGI has played an important role in providing timely data when the costs and its availability is a major concern particularly during emergency and humanitarian efforts. The worldwide crowdsourcing efforts through OpenStreetMap (OSM), the most successful open platform for collaborative mapping have managed to assist authorities such as during the 2017 Mexico earthquake and Hurricane Irma and Maria that impacted several countries in America continent. However, there are lots of arguments on the quality of VGI, particularly in regard to OpenStreetMap (OSM). Therefore, this study was carried out to assess the quality of OSM against authoritative sources using a dataset of Putrajaya, Malaysia. This study assessed the quality of OSM, including completeness, positional and thematic accuracy. From the preliminary assessment, the results showed that the OSM data was good in terms of relative positioning accuracy, particularly in road feature, but still poor in terms of completeness and thematic correctness against the reference dataset. This study is significant with an expected contribution to the assessment of quality of VGI in developing countries that commonly facing slow-paced progress in mapping the OSM. The findings could be used as a basis for various parties that plan to use OSM in Malaysia, particularly Putrajaya as a supplementary data to authoritative sources, including data supplied by the professional surveyors

Granite Exploration by using Electrical Resistivity Imaging (ERI): A Case Study in Johor

Electrical Resistivity Imaging (ERI) is a tool used in near surface geophysical surveys by flowing an electric current through electrodes that were injected into the ground. The usage of electrical resistivity imaging (ERI) method dominated by geophysicist has increased tremendously in geotechnical engineering application owing to the efficiency and effectiveness of the method in term of time, cost and also data coverage. The survey performed with respect to the particular reference to ERI in determining the granite rock underneath the ground. There were seven (7) lines of ERI performed at the study area by using ABEM Terrameter LS 2 set of equipment based on Schlumberger protocol. Six (6) boreholes were also drilled to obtain engineering properties of rock at the study area. In order to develop the relationship between resistivity and engineering properties, a comparison between borehole field test result and the resistivity value were made. Results from the ERT indicated the presence of zones with high resistivity values identified as overburden soil, fractured granite and solid granite. The findings of this study also showed that the electrical resistivity imaging coupled with borehole drillings were applicable tools for the determination of the granite rock underneath the ground via subsurface profiles and such as depth of overburden soil and engineering properties of soil

Motion planning and tracking trajectory of an autonomous emergency braking pedestrian (AEB-P) system based on different brake pad friction coefficients on dry road surface

Accidents between vehicles and pedestrians usually occur when a pedestrian is crossing the road. An Autonomous Emergency Braking Pedestrian (AEB-P) is introduced to prevent collisions between vehicles and pedestrians. However, the performance of an AEB-P will be reduced when the brake pad is worn out on a dry road. In this study, the motion planning, namely Vehicle Conditional Artificial Potential Field (VC-APF), including a warning signal and emergency brake phase that generate the vehicle’s deceleration, is proposed to analyze the effect of brake pad on the AEB-P performance. Then, the vehicle’s deceleration is tracked by the tracking trajectory, where the PI controller is adapted to provide the optimum braking force. The function of PI control is to ensure the vehicle’s deceleration is approaching the desired deceleration. The performance of the proposed method has been simulated on the dry road surface with different brake pad coefficients; 0.4, 0.35, and 0.24. The simulation results show that the vehicle manages to stop colliding with a pedestrian on the dry road surface at the minimum safety distance range of 2.7-2.9 meters

Relativistic shells: Dynamics, horizons, and shell crossing

We consider the dynamics of timelike spherical thin matter shells in vacuum. A general formalism for thin shells matching two arbitrary spherical spacetimes is derived, and subsequently specialized to the vacuum case. We first examine the relative motion of two dust shells by focusing on the dynamics of the exterior shell, whereby the problem is reduced to that of a single shell with different active Schwarzschild masses on each side. We then examine the dynamics of shells with non-vanishing tangential pressure $p$, and show that there are no stable--stationary, or otherwise--solutions for configurations with a strictly linear barotropic equation of state, $p=\alpha\sigma$, where $\sigma$ is the proper surface energy density and $\alpha\in(-1,1)$. For {\em arbitrary} equations of state, we show that, provided the weak energy condition holds, the strong energy condition is necessary and sufficient for stability. We examine in detail the formation of trapped surfaces, and show explicitly that a thin boundary layer causes the apparent horizon to evolve discontinuously. Finally, we derive an analytical (necessary and sufficient) condition for neighboring shells to cross, and compare the discrete shell model with the well-known continuous Lema\^{\i}tre-Tolman-Bondi dust case.Comment: 25 pages, revtex4, 4 eps figs; published in Phys. Rev.

Study of human driving skill in expected and guided conditions

This day, Human Machine System (HMS) consider being a proven technology, which has gained an important role in various human activities. One of the most recent developments in this area is Human Adaptive Mechatronics (HAM) approach for enhancing human skills. This approach therefore is different compared to an ordinary HMS, in terms of its ability to adapt to changes in its environment and in the human changing level of skills. The crucial issue in HAM is in evaluating the human skills level on machine operation. In this paper, a skill index to quantify the performance of human drivers is studied in expected and guided conditions. The experiments are carried out on human subjects in normal driving. From this experiment, a new skill index formula is proposed based on the logical conditions and the definition of skill in HAM