Narrow Results

A probabilistic model is proposed with dynamics which naturally leads to a bottleneck in the number of mitochondria transmitted from one host-cell generation to the other. We take into account deleterious mutations during the replication of mitochondria within a cell of a germ-line and introduce selection inside the cell reproduction mechanism. The bottleneck size strongly depends on the selection mechanism and on the maximum number of mitochondria per cell. We obtain that the smaller the maximum allowed number of mitochondria per cell during replication, the tighter the bottleneck. Such a result is in agreement with the fact that species producing small litters provide developing oocytes with a smaller number of mitochondria. This amplifies the differences among oocytes leading to competition and removal of inferior cells.

As a kind of bottleneck, the lane closing has seldomly been investigated with cellular automata model. In this paper, we study this issue using the cellular automata traffic flow model. The capacity and the density distribution of this kind of bottleneck are discussed in details. We find that (i) the capacity of the bottleneck is a little smaller than the maximum flow rate of single-lane road; (ii) different regulations may lead to different density distributions of the vehicles upstream of the lane closing. Moreover, the density inversion phenomenon is reported under certain conditions. This enlightens us to propose that the phenomenon of density inversion reported in many publications may be caused by the bottlenecks on the highway.

In this paper, we investigate the effect of density feedback on the two-route scenario with a bottleneck. The simulation and theory analysis shows that there exist two critical vehicle entry probabilities ${\alpha }_{c1}$ and ${\alpha }_{c2}$. When vehicle entry probability $\alpha \le {\alpha }_{c1}$, four different states, i.e. free flow state, transition state, maximum current state and congestion state are identified in the system, which correspond to three critical reference densities. However, in the interval ${\alpha }_{c1}<\alpha <{\alpha }_{c2}$, the free flow and transition state disappear, and there is only congestion state when $\alpha \ge {\alpha }_{c2}$. According to the results, traffic control center can adjust the reference density so that the system is in maximum current state. In this case, the capacity of the traffic system reaches maximum so that drivers can make full use of the roads. We hope that the study results can provide good advice for alleviating traffic jam and be useful to traffic control center for designing advanced traveller information systems.

The steady-state dynamics of a two-channel TASEP coupled with Langmuir kinetics in the presence of a localized bottleneck are investigated under a fully asymmetric lane-changing rule. A hybrid mean-field approach is adopted to generate the density profiles as well as phase diagrams. The effect of lane-changing rate and strength of bottleneck on the stationary dynamics of the system has also been investigated. It is observed that an increase in lane-changing rate weakens the effect of bottleneck. As a part of studying the shock dynamics, we have identified and analyzed turning effect in the movement of shock with respect to lane-changing rate. Our theoretical arguments are in good agreement with extensively performed Monte-Carlo simulations.

Various car-following models (CMs) have been developed to capture the complex characteristics of microscopic traffic flow, among which the coupled map CM can better reveal and reflect various phenomena of practical traffic flow. Capacity change at bottleneck contributes to high-density traffic flow upstream the bottleneck and contains very complex dynamic behavior. In this paper, we analyze the effect of speed bottleneck on the spatial-temporal evolution characteristics of traffic flow, and propose a method to reduce traffic congestion with the feedback control signal based on CM. Simulation results highlight the potential of using the feedback signal to control the stop-and-go wave and furthermore to alleviate the traffic congestion effectively.

Motivated by a crane assignment problem, we consider a Euclidean bipartite matching problem with edge-crossing constraints. Specifically, given $n$ red points and $n$ blue points in the plane, we want to construct a perfect matching between red and blue points that minimizes the length of the longest edge, while imposing a constraint that no two edges may cross each other. We show that the problem cannot be approximately solved within a factor less than 1:277 in polynomial time unless $\text{P}\text{=}\text{NP}$. We give simple dynamic programming algorithms that solve our problem in two special cases, namely (1) the case where the red and blue points form the vertices of a convex polygon and (2) the case where the red points are collinear and the blue points lie to one side of the line through the red points.

At present, the Chinese economy has entered a “new normal” state. Since the State Council announced the seven strategic emerging industries in 2010, the strategic emerging industries have provided key supports to steady growth, structural adjustment, development of the new economy and in fostering new momentum. In this paper, using the new energy industry as a starting point, we try to study the motivation, bottleneck and countermeasures of promoting the development of strategic emerging industries. First, a more in-depth interpretation to the scientific connotation of strategic emerging industries has been done. Then, we analyze the motivation of the strategic emerging industries from the perspective of the diamond model. Meanwhile, on the basis of combining the present situation, we analyze the bottleneck and countermeasures of the development of emerging strategic industries.

In this paper, we investigate the WIP inventory control for electronic manufacturing services, in order to improve the timely delivery rate of electronics manufacturing service companies and enhance competitiveness. First, we establish the WIP inventory control model for the bottleneck process by introducing the theory of constraints. Based on this, we establish the WIP inventory control model for electronic manufacturing services by introducing the classical control theory and use PID algorithm to make the WIP inventory around the bottleneck to be under the effective control. Finally, we built the WIP inventory control model for a case study of the production line of keyboard for a mobile phone and apply Matlab/Simulink to demonstrate this model.