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[en] A number of cars drive along a narrow road that does not allow overtaking. Each driver has a certain maximum speed at which he or she will drive if alone on the road. As a result of slower cars ahead, many cars are forced to drive at speeds lower than their maximum ones. The average velocity in the queue offers a non-trivial example of a mean value calculation. Approximate and exact results are obtained using sampling, enumeration and calculations. The geometrical nature of the problem as well as the separate levels of averaging involved are emphasized. Further problems suitable for exploration in student projects are outlined
[en] In this paper, multi-objective optimization of a rack-and-pinion steering linkage is proposed. This steering linkage is a common mechanism used in small cars with three advantages as it is simple to construct, economical to manufacture, and compact and easy to operate. In the previous works, many researchers tried to minimize a steering error but minimization of a turning radius is somewhat ignored. As a result, a multi-objective optimization problem is assigned to simultaneously minimize a steering error and a turning radius. The design variables are linkage dimensions. The design problem is solved by the hybrid of multi-objective population-based incremental learning and differential evolution with various constraint handling schemes. The new design strategy leads to effective design of rack-and-pinion steering linkages satisfying both steering error and turning radius criteria
[en] Using a method originally developed for the random matrix theory, we derive an approximate mathematical formula for the number variance ΔN(L) describing the rigidity of particle ensembles with a power-law repulsion. The resulting relation is compared with the relevant statistics of the single-vehicle data measured on the Dutch freeway A9. The detected value of the inverse temperature β, which can be identified as a coefficient of the mental strain of the car drivers, is then discussed in detail with the relation to the traffic density ρ and flow J.
[en] Highlights: → A car-following model with consideration of roadside memorial has been developed. → We use it to explore the effects of the roadside memorial on traffic system. → Results show that it can describe complex phenomena resulted by roadside memorial. → What's more, considering roadside memorial can improve traffic safety. → The results help us understand effects of roadside memorial on traffic flow. -- Abstract: In this Letter, a car-following model with consideration of roadside memorial is proposed. The numerical results show that the proposed model can qualitatively describe the impacts of roadside memorial on traffic flow and the traffic risk coefficient. It is also shown that roadside memorial can enhance the traffic safety.
[en] This article explains why: (a) consumers underinvest in new car fuel economy by opting to buy large vehicles; (b) macro shifts in vehicle classes have occurred in the last decades; and how (c) the effects of vehicle fuel economy and shifts in vehicle type influence the growth path of gasoline demand, which is the key to designing effective energy efficiency goals for transport. From 2008, 1.9 EXJ (Exajoules) of energy were consumed in Japan by private vehicles producing 124 MtCO2 emissions. For the period 1980 to 2008, we estimated: (1) gasoline demand for three vehicle sizes; (2) vehicle sales; (3) new car fuel economy changes (the ‘real’ technical change); and (4) vehicle stocks. Using a data sample for 1980–2008 we found that: (a) in the short term consumers buy fuel economy, that is sales of mini and small cars increase, but this is not sustained in the long term: and (b) consumers increasingly traded in their cars for larger cars. A further finding was that gasoline demand is projected to increase to 2.3 EXJ by 2035, even with a growing number of mini cars. The policy implication is clear: Japan’s policy to reduce oil dependency to 80% by 2030 is in peril as long as buyers prefer larger cars and drive ever longer distances.
[en] This paper explores and investigates the dynamic characteristics of car chassis structure by using experimental modal analysis (EMA) method and modal testing. Dynamic characteristics are divided into three parameters include natural frequency, damping factor and mode shape. In this study, modal testing was performed on the car chassis including the impact hammer and shaker test. Data analyzer was used to convert the response signal from the sensor, which was in the time domain to frequency domain. Result obtained from both methods, is compared on each axis (X, Y and Z axis). However, small discrepancy was observed in terms of natural frequency, which is within the range of 5%. Based on the results, interpretation and comparison were made for both methods.
[en] Evaluating country manufacturing location attractiveness on various performance measures deepens the analysis and provides a more informed basis for manufacturing site selection versus reliance on labor rates alone. A short list of countries can be used to drive regional considerations for site-specific selection within a country. Design/methodology/approach: The two-step multi attribute decision model contains an initial filter layer to require minimum values for low weighted attributes and provides a rank order utility score for twenty three countries studied. The model contains 11 key explanatory variables with Labor Rate, Material Cost, and Logistics making up the top 3 attributes and representing 54% percent of the model weights. Findings: We propose a multi attribute decision framework for strategically assessing the attractiveness of a country as a location for manufacturing automobiles. Research limitations/implications: Consideration of country level wage variation, specific tariffs, and other economic incentives provides a secondary analysis after the initial list of candidate countries is defined. Practical implications: The results of our modeling shows China, India, and Mexico are currently the top ranked countries for manufacturing attractiveness. These three markets hold the highest utility scores throughout sensitivity analysis on the labor rate attribute weight rating, highlighting the strength and potential of manufacturing in China, India, and Mexico. Originality/value: Combining MAUT with regression analysis to simplify model to core factors then using a “must have” layer to handle extreme impacts of low weight factors and allowing for ease of repeatability.
[en] This book deals with the inventions invented by kids such as a utility helmet, a useful drawing board, automatic safe device, telephone for the blind, a peaceful washboard, roly poly milk bottle, seat belt with height control, gas hose to prevent thief, portable magic soap, useful bus handle, convent desk, a paper cup attached a spoon, a useful washboard, dressing room using moveable small cymbals, fluorescent light which is easy to put in a new one, rods for night, curtain for cars, spray shampoo, and a good calendar.