scholarly journals In Situ Measurement of Discomfort Curves for Seated Subjects in a Car on the Four-Post Rig

2014 ◽  
Vol 2014 ◽  
pp. 1-14
Author(s):  
T. Ibicek ◽  
A. N. Thite

The aim of this study is to measure and quantify perceived intensity of discomfort due to vibration in a vehicle in situ considering complete vehicle dynamic behaviour. The shaker table based discomfort curves or the road test results may not accurately and universally indicate the true level of human discomfort in a vehicle. A new experimental method, using a seated human in a car on the four-post rig simulator, is proposed to quantify discomfort. The intensity of perception to vibration decreased with decreasing input and increasing frequency; the rate of change is different from the published literature; the difference is large for angular modes of inputs. Vehicle dynamic response is used to inform and analyse the results. The repeatability of the method and the fact that they are in situ measurements may eventually help reduce reliance on the road tests. Furthermore, discomfort curves obtained, subsequently, can be used in predictive models.

1949 ◽  
Vol 22 (1) ◽  
pp. 259-262
Author(s):  
J. F. Morley

Abstract These experiments indicate that softeners can influence abrasion resistance, as measured by laboratory machines, in some manner other than by altering the stress-strain properties of the rubber. One possible explanation is that the softener acts as a lubricant to the abrasive surface. Since this surface, in laboratory abrasion-testing machines, is relatively small, and comes repeatedly into contact with the rubber under test, it seems possible that it may become coated with a thin layer of softener that reduces its abrasive power. It would be interesting in this connection to try an abrasive machine in which a long continuous strip of abrasive material was used, no part of it being used more than once, so as to eliminate or minimize this lubricating effect. The fact that the effect of the softener is more pronounced on the du Pont than on the Akron-Croydon machine lends support to the lubrication hypothesis, because on the former machine the rate of wear per unit area of abrasive is much greater. Thus in the present tests the volume of rubber abraded per hr. per sq. cm. of abrasive surface ranges from 0.03 to 0.11 cc. on the du Pont machine and from 0.0035 to 0.0045 cc. on the Akron-Croydon machine. On the other hand, if the softener acts as a lubricant, it would be expected to reduce considerably the friction between the abrasive and the rubber and hence the energy used in dragging the rubber over the abrasive surface. The energy figures given in the right-hand columns of Tables 1 and 3, however, show that there is relatively little variation between the different rubbers. As a test of the lubrication hypothesis, it would be of interest to vary the conditions of test so that approximately the same amount of rubber per unit area of abrasive is abraded in a given time on both machines; this should show whether the phenomena observed under the present test conditions are due solely to the difference in rate of wear or to an inherent difference in the type of wear on the two machines. This could most conveniently be done by considerably reducing the load on the du Pont machine. In the original work on this machine the load was standardized at 8 pounds, but no figures are quoted to show how abrasion loss varies with the load. As an addition to the present investigation, it is proposed to examine the effect of this variation with special reference to rubbers containing various amounts and types of softener. Published data on the influence of softeners on the road wear of tire rubbers do not indicate anything like such large effects as are shown by the du Pont machine. This throws some doubt on the value of this machine for testing tire tread rubbers, a conclusion which is confirmed by information obtained from other workers.


Author(s):  
Runze Chen ◽  
Yumin Chen ◽  
Hanlong Liu ◽  
Kunxian Zhang ◽  
Ying Zhou ◽  
...  

Electrolytic desaturation is a potential method for improving the liquefaction resistance of the liquefiable foundation by reducing the soil saturation. In this study, in-situ desaturation tests were performed to investigate the resistivity of soil at different depth and the water level of the foundation under different current. The test results show that at constant currents of 1 A (Ampere, unit of the direct current), 2 A and 3 A, the saturation of the treated foundation reached 87%, 83% and 80%. During the electrolysis process, the generated gas migrates vertically and horizontally under the influence of buoyancy and gas pressure. In the end of electrolysis, the gas inside the sand foundation basically migrates vertically only. The higher current intensity employed for electrolysis will affect the uniformity and stability of the gas. At constant currents of 1 A, 2 A and 3 A, the difference between the maximum and minimum degree of saturation in the treated foundation was 14%, 18% and 19%; and after electrolysis halted for 144 h, the saturation in the treated foundation was 90%, 85% and 87%. The electricity consumption analysis indicates that the desaturation method has excellent economic benefits in the treatment of saturated sand foundations.


2014 ◽  
Vol 536-537 ◽  
pp. 176-179 ◽  
Author(s):  
Du Hyung Cho ◽  
M. Naushad Ali ◽  
Seok Ju Chun ◽  
Seok Lyong Lee

Object association and tracking have attracted great attention in the computer vision. In this paper, we present an object association and tracking method for monitoring multiple vehicles on the road based on objects' visual features and the similarity comparison between them. First, we identify vehicles using the difference operation between the current frame in CCTV image sequences and the referential images that are stored in a database, and then extract various features from the vehicles identified. Finally, we associate the objects in the current frame with those in the next frames using similarity comparison, and track multiple objects over a sequence of CCTV image frames. Empirical study using CCTV images shows that our method has achieved the considerable effectiveness in tracking vehicles on the road.


Zootaxa ◽  
2017 ◽  
Vol 4291 (3) ◽  
pp. 531
Author(s):  
OLIVIER S. G. PAUWELS ◽  
HENNING LARSEN ◽  
WINAI SUTHANTHANGJAI ◽  
PATRICK DAVID ◽  
MONTRI SUMONTHA

We describe Oligodon huahin sp. nov. from a bamboo forest locality on the road to Pala-U waterfall, Hua Hin District, Prachuap Khiri Khan Province, peninsular Thailand. It is characterized by a maximal known SVL of 553.7 mm; 6 maxillary teeth, the posterior two enlarged; 17-17-15 or 17-15-15 dorsal scale rows; 166–173 ventrals and 35–41 subcaudals in males; a single anal; deeply forked hemipenes lacking spines and papillae, extending in situ to the 14th subcaudal; faint to nearly indistinct vertebral, paravertebral and lateral stripes; no dorsal or supracaudal blotches or crossbars; and an uniformly ivory venter lacking subrectangular or squarish blotches. We also report the first finding of Oligodon deuvei in Thailand based on a specimen from Loei Province. 


2017 ◽  
Vol 16 (6) ◽  
pp. 493-497
Author(s):  
M. G. Solodkaya

Traffic circulation on highways is a random process. Therefore automotive damage rate and, respectively, roads on which they are moving is subjected to regularities of random processes. Dynamic processes of vehicle-road interaction are determined to various extents by a host of factors that include road pavement evenness and characteristics of moving vehicles. For this reason the following task has been set: to reveal the most significant factors and mathematically correlate values of vehicle dynamic loads with a quality of road pavement and vehicle speed. Such task statement has not been solved adequately and this situation determines importance and novelty of the investigations in the given direction. While solving the mentioned task the investigations which have been carried out under real-life conditions and with the help of real-life objects are considered as the most reliable ones. However, preparation and execution of such experiments as needed significantly complicates their implementation. In this regard it looks rather expediential to combine a factorial experiment with the tests of a checked model while using ECM with stage-by-stage parameter fixation of working processes passing in “vehicle-road” system, comprehensive assessment pertaining to influence of the selected factors and selection of their optimum combination. Mathematical dependence has been obtained to evaluate influence of several external factors on optimization of vehicle dynamic load on the road. This component makes it possible to attain a simplified and adequate description of element interaction in “vehicle – road” system. While investigating influence of pavement irregularities on maximum dynamic loads on the road influence rate of the selected factors is determined in the following sequence: vehicle weight, pavement evenness and speed of transport facility.


2021 ◽  
Vol 11 (24) ◽  
pp. 11720
Author(s):  
Rosolino Vaiana ◽  
Cesare Oliviero Rossi ◽  
Giusi Perri

Subgrade conditions significantly affect functionality of the road pavement during its service life. Among the different stabilization techniques for upgrading poorly performing in-situ soil subgrades, an economically attractive example involves the use of waste materials, such as lignin. A deep bibliographic analysis of previous studies is carried out in the first section of this paper. The literature review suggests that use of lignin as a stabilizing agent of road subgrade soils is not completely consolidated. In addition, this study reports an investigation on the strength and performance characteristics of a lignin-treated clayey soil. Several experimental tests were carried out on both the untreated and lignin-treated soils in order to shed some light on different aspects with limited knowledge available, such as the behaviour of the stabilised soil in specific conditions (e.g., the presence of water). Finally, the test results are discussed and compared with those obtained when the same soil is treated with lime, which is more widely used. The most relevant finding is the poor ability of lignin to upgrade the bearing capacity of the soil in wet conditions compared to lime; on the contrary, the presence of lignin helped in controlling the swelling potential of this type of soil.


2018 ◽  
Vol 1 (1) ◽  
pp. 123-128
Author(s):  
Tarmizi Taher ◽  
Alexander Sebayang ◽  
Bustami Syam

Speed bump adalah mekanisme yang dipasang pada jalan untuk mengurangi laju kendaraan dengan tujuan keamanan. Pada penelitian ini dikembangkan sebuah speed bump yang memiliki fungsi ganda, yaitu mengurangi laju kendaraan dan sebagai pembangkit daya. Sistem pembangkit daya terdiri dari pasangan roda gigi, poros, roda gila, pegas, rantai dan kumparan generator. Prototipe kemudian diuji pada tingkat kecepatan yang bervariasi. Besar voltase dan arus yang dibangkitkan diukur. Hasil pengujian menunjukkan untuk massa pengendara 400 kg dan variasi kecepatan kendaraan 5 km/jam, 10 km/jam, dan 15 km/jam, dihasilkan tegangan 18 Voltase dan menghasilkan arus sebesar 0.27 ampere. Hasil yang dicapai ini masih kecil, sehingga mendorong peneliti memperbaiki desain stasiun listrik speed bump generasi ke-2. Speed bump is a mechanism that is installed on the road to reduce the speed of the vehicle with safety objectives. In this study a speed bump that has a dual function was developed, namely reducing the speed of the vehicle and as a power plant. The power generation system consists of pairs of gears, shafts, flywheels, springs, chains and generator coils. The prototype is then tested at varying speed levels. The voltage and current generated are measured. The test results show for the mass of the driver 400 kg and variations in vehicle speed 5 km / h, 10 km / h, and 15 km / h, voltage 18 voltage is generated and produces a current of 0.27 amperes. The results achieved are still small, prompting researchers to improve the design of the 2nd generation speed bump electric station.


Energies ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 888 ◽  
Author(s):  
Hua Zhang ◽  
Shunde Yin ◽  
Bernt Aadnoy

Borehole breakouts appear in drilling and production operations when rock subjected to in situ stress experiences shear failure. However, if a borehole breakout occurs, the boundary of the borehole is no longer circular and the stress distribution around it is different. So, the interpretation of the hydraulic fracturing test results based on the Kirsch solution may not be valid. Therefore, it is important to investigate the factors that may affect the correct interpretation of the breakdown pressure in a hydraulic fracturing test for a borehole that had breakouts. In this paper, two steps are taken to implement this investigation. First, sets of finite element modeling provide sets of data on borehole breakout measures. Second, for a given measure of borehole breakouts, according to the linear relation between the mud pressure and the stress on the borehole wall, the breakdown pressure considering the borehole breakouts is acquired by applying different mud pressure in the model. Results show the difference between the breakdown pressure of a circular borehole and that of borehole that had breakouts could be as large as 82% in some situations.


Tennis has become an extremely complex sport, with tennis players needing a team of specialists to maximise their sports performance. Performance tennis has proven that the difference between the players, in the conditions of similar technical-tactical performances, is made by the physical and mental training. Our paper aimed to investigate the subjective reality of junior tennis players in order to optimise their actions and activities by identifying a psychomotor and cognitive model of athletes ranked in the top area nationally. The research involved 75 tennis players - 40 boys and 35 girls aged between 14 and 16 years. The materials used were represented by the PSISELTEVA psychological testing system developed by the RQ Plus Company and calibrated to the Romanian population, which contains: levers, desk with buttons, pedals. The tests belonging to the computerised battery used in the research are: TRS (simple reaction time), TRD (discrimination reaction time), RCMV (intersegmental coordination), TUD (eye-hand coordination), ANALOGIE (analogical transfer), TAC (attention concentration), MT (topographical memory) and RNE (resistance to mental fatigue). Through the Mann-Whitney (U) test, significant differences were identified between the first tennis players in the national ranking and the players placed in the middle or final zone of the ranking, in terms of different psychomotor and cognitive coordinates (investigated in various environmental conditions). The results obtained are useful both for specialists working in the field of tennis (coaches, sports psychologists, physical trainers), athletes (boys and girls) aspiring on the road to great performance, but also for sports clubs.


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