Research on development of urban taxi supply based on influence factors classification

In order to determine the regulations of the development of taxi supply under entry regulations in Chinese cities, an improved neural network model is applied to find the particular years when the government artificially puts new taxis into the market, and then extract the political influence from the taxi supply. The model is also utilized to study the relationships between the adjusted taxi supply and non-policy factors. A case study of Nanjing city is conducted. The results show that 2001 and 2007 are the particular years that the Nanjing government artificially put new taxis into its taxi market, which is in accordance with the five-year plan of China and the local development plans. The results also show that the improved neural network model has a good performance in expositing the evolution of adjusted taxi supply related to non-policy factors.

Effects of behavioral characteristics of taxi drivers on safety and capacity of signalized intersections

Comparative analyses were conducted to compare the effects of the behavioral characteristics of the drivers of taxis and private cars on the capacity and safety of signalized intersections. Data were collected at sixteen signalized intersections in the Nanjing area in China. The risk-taking behaviors of the drivers of taxis and private cars were compared. The results suggest that 19.9% of taxi drivers have committed at least one of the identified risky behaviors, which is 2.37 times as high as that of the drivers of private cars(8.4%). The traffic conflicts technique was used to estimate the safety effects of taxis and private cars. The overall conflict rate for taxis is 21.4% higher than that for private cars, implying that taxis are more likely to be involved in conflicts. Almost all of the identified traffic conflicts can be attributed to certain levels of risk-taking behaviors committed by either taxi drivers or the drivers of private cars, and taxi drivers are more likely to be at fault in a conflict. Failure to yield to right-of-way and improper lane change is the leading causes of the conflicts in which taxis are at-fault. The research team further studied the effects of taxis on the queue discharge characteristics at signalized intersections. The results show that the presence of taxis significantly reduces both start-up lost time and saturation headways. The effects of taxis on saturation flow rates are dependent on the proportion of taxis in the discharge flow, and the saturation flow rates increase with the increase in the proportion of taxis. The adjustment factors for various proportions of taxis for different turning movements are then calculated to quantitatively evaluate the effects of taxis on the capacity of signalized intersections.

Understanding taxi driver's cruising behavior with ZIP model

The taxi drivers' cruising pattern was learned using GPS trajectory data collected in Shenzhen,China.By employing zero-inflated Poisson model,the impacts of land use and previous pick-up experience on cruising decision were measured.The cruising strategies of different types of drivers as well as the top one driver were examined.The results indicate that both land use and previous pick-up experience affect travel behavior with the former's influence(7.07×10-4 measured by one of the coefficients in zero-inflated Poisson model) being greater than the latter's(4.58×10-5) in general,but the comparison also varies across the types of drivers.Besides,taxi drivers' day-to-day learning feature is also proved by the results.According to comparison of the cruising behavior of the most efficient and inefficient driver,an efficient cruising strategy was proposed,that is,obeying the distribution of land use in choice of cruising area,while learning from pick-up experience in selection of detailed cruising location.By learning taxi drivers' cruising pattern,the development of measures of regulating travel behaviors is facilitated,important factor for traffic organization and planning is identified,and an efficient cruising strategy for taxi drivers is provided.

How relevant are engineering samples in the management of personal dust exposure?

A directive, legislated by the South African Department of Minerals and Energy(DME) in 1997, was introduced to reduce the dust exposures of continuous miner(CM) operators to below 5 mg/m3, when measured at the operator's cab position. The focus of this paper is to review the effectiveness of observing this rule for almost two decades and discuss industry perceptions arising from the application of this rule. The results have demonstrated that the engineering sample cannot predict the personal shift dust exposure of a CM operator. Therefore, it is recommended that the engineering sampling, as currently practiced,should be reviewed with the objective to discontinue and replace it by the approved PDM3700 realtime dust monitor.

Learning taxis' cruising patterns with Ripley's K function

Taxi drivers' cruising patterns are learnt with GPS trajectory data collected in Shenzhen, China. By employing Ripley's K function, the impacts of land use and pick-up experience on taxis' cruising behavior are investigated concerning about both intensity of influence and radius of influence. The results indicate that, in general, taxi drivers tend to learn more from land use characteristics than from pick-up experience. The optimal radius of influence of land use points and previous pick-up points is 14.18 km and 9.93 km, respectively. The findings also show that the high-earning drivers or thorough drivers pay more attention to land use characteristics and tend to cruise in high-density area, while the low-earning drivers or focus drivers prefer to learn more from previous pick-up experience and select the area which is far away from the high-density area. These findings facilitate the development of measures of managing taxi's travel behavior by providing useful insights into taxis' cruising patterns. The results also provide useful advice for taxi drivers to make efficient cruising decision, which will contribute to the improvement of cruising efficiency and the reduction of negative effects.

Private Car Ownersip Jumps 16% in 6 Months

More than 13 million cars in China were privately owned by the end ＆June up 16% over the end of last year, according to the Ministry of Public Security.

Path planning for taxi of carrier aircraft launching

Launching efficiency is an important index to measure the fighting capacity of an aircraft carrier. The study on path planning for taxi of carrier aircraft is of great significance for enhancing the launching efficiency. Considering the launching efficiency and the safety in operation of carrier aircraft launching and taking into account the carrier aircraft maneuver performance, deck environment and feature of mission, we proposed a conceptual model which contains the key elements of path planning for taxi of carrier aircraft. Subsequently, the objective function for the path planning problem and its mathematical model containing various constraints were established. With the A * search algorithm, a dynamic weight heuristic function was designed. According to the characteristic of path planning model for taxi of carrier aircraft, a simple and effective detection method was introduced. Finally, a feasible path for taxi of carrier aircraft, which meets the constraints, was presented. Taking the Nimitz-class aircraft carrier as an example, the paths for taxi of carrier aircraft launching from elevators to catapults were planned. Simulation results demonstrated the rationality of the model and the effectiveness of the algorithm.

Synthetic immunity to break down the bottleneck of cancer immunotherapy

As a result of recent breakthroughs in cancer immunotherapies, unprecedented and durable remission, and even cure, has been reported in some patients. Importantly, this progress has been achieved, not by the induction of immunity, but by the delivery of immunity in the form of engineered antibodies （cAbs） or effector T cells. However, these single-target technologies have failed to result in a therapeutic effect in some patients, and evidence suggests that further advances depend on an effective strategy for coping with cancer heterogeneity and dynamics. A synthetic immunity （SI） strategy is proposed to achieve this goal. The fundamental basis of SI involves the generation of a panel of cAbs and antibody-retargeted CTLs designed to destroy all cell lineages of a cancer with high specificity. This goal can be achieved only when the composition of the cAbs is determined using a systematic approach, i.e., selecting the antigens targeted by the cAbs based on an epitope-tree illustrating the clonal antigen architecture of the cancer. Integration of technologies that increase the epitope breadth, cAb affinity and T cell activity will further enhance the efficacy of SI. Using DNA vectors to express the eAbs will be a safe, effective and affordable solution.

Generation of Different Classes of Multipartite Entanglement Using Cavity-QED

Using a system of cavity quantum electrodynamics （QED） we present two schemes for multipartite entan- glement generation. In the first scheme, a three-level atom is interacting with three cavities successively. In the second one, two three-level atoms are interacted with a coherent optical cavity. These protocols allow us to generate the six c/asses of tripartite entanglement （GHZ, W, A-B-C, AB-C, C-AB, and B-AC class states） by controling the interaction time between atoms and cavities. Moreover, they allow us to generate entanglement between the cavity fields degrees of freedom （from the first scheme）, and a mixed entanglement between the cavity field degrees of freedom and the atomic degrees of freedom.