单片机控制的简单计算器外文文献(4)

experimentations with this type of system are promising, with minimum delay of vehicles at intersections. However, it lacks the coordination aspect between multiple traffic lights, which is one of the most important problems that affects the design of such systems. Roozemond [13] presents agent model acting autonomously while

sharing gathered data. Then, intersections use this information to make both short and long term traffic predictions with accordingly adjustment. Bazzan [14] has used a decentralized approach combining MAS and evolutionary game theory. This approach models each intersection as an individually motivated agent which must focuses not only on getting vehicles through the intersection, but also on reducing travel times for all vehicles.

2.4.1. Traffic lights models using reinforcement learning

Several applications of reinforcement learning (RL) exist, such as in the works

[15–19]. These models attempt to infer a reward model for various pairs of state/action by allowing interaction between the controlling agents and traffic

environment. In a large network, the problem of the large number of these pairs restricts the use of RL method in this domain, (convergence problem).

2.4.2. Traffic lights models using swarm optimization methods

The swarm optimization methods are another field of artificial intelligence which was applied to control the traffic lights. The works of Oliveira [20] use the principle of optimization distribution of signal based on the amount of pheromone emitted by waiting vehicles. In [21], authors propose autonomous intersection management

(AIM) based on Ant Colony System (ACS) algorithm that evacuates vehicles for each sequence of vehicles arrivals and for large number of lanes. In addition, numerous works has used evolutionary computing to optimize signal plans within a network

[22–24]. These approaches typically aim to represent the signal plans for the entire network as a set of chromosomes and then an evolutionary algorithm is applied. However, this type of solution requires an extremely high puissance of computing with the network size. In complex networks, real-time control may be impossible because the computation may not complete in a suitable time.

2.4.3. Adaptive traffic lights models

Adjustment of traffic lights configuration is the key aspect in optimization of traffic flow model presented in major previous works. However, in the real world, the

configuration parameters of the traffic lights are based on data and designer’s model which is updated frequently.

The multi-agents model can be used in order to deal with these real situations. But, to provide more accurate data, it must be more adaptive with change. The idea is to

endow the system with its own control system, so it can face its dynamic environment and the multiple situations it will encounter. Thereby, the self-organized system is a particularly appropriate approach to apply within traffic control.

Gershenson [25, 26] presented one of the initial applications of self-organized systems to traffic signal control. The author shows that an agent-based solution is capable of controlling traffic signals effectively. Lammer and Helbing extend this work [27] and present another self-organized control system which is shown to effectively handling several traffic scenarios within hypothetical grid-like networks.

The approach proposed by Xaio-Feng Xie [28], presents a model of aggregates incoming vehicles into clusters which enables the real-time computation of signal timing policies. These Self-scheduling approaches give rise to a self-organizing system.

Zhou and al. [29] provides an adaptive traffic lights algorithm which selects the sequence of phases in a cycle, according to the following criteria: the presence of priority vehicles, totalwaiting time and queue length. This algorithm, however, requires the same type of vehicle with same speed.

第三篇范文：简易计算器设计 文献综述

简易计算器设计的文献综述

随着社会的发展，科学的进步，微电子技术的发展有着日新月异的变化。电子产品的更新速度之快就更不足为奇了, 单片机的应用已经越来越贴近生活，用单片机来实现一些电子设计也变得容易起来。本课题就是利用单片机设计简易的计算器。

1. 引言

1.1 单片机国内外现状与发展前景

当今已是信息化时代，社会快速发展和信息技术革命的不断深入使随着现代科技的飞速发展，单片机已经在各个领域得到越来越广泛的应用，由于其体积小，功耗低这两个基本特征，在通讯，家电，工业控制，仪器仪表，汽车等产品中都可以看到单片机的身影，可以说几乎很难找到哪个领域没有单片机的踪迹，且逐渐地发展成了一门比较关键的技术学科。单片机技术也随着集成电路技术的进步在近几年飞速的发展，这种发展可以分为两方面：一方面在硬件上单片机内部集成了越来越多的功能部件，如A/D，D/A，PWM，WATCHDOG，LCD驱动，串行口，大容量FLASH存储器等；另一方面在开发手段上从汇编语言向高级C语言过度，计算机仿真调试，IAP，ISP技术的应用使单片机开发周期大大的缩短，为各类产品更新，软件的升级提供了可靠的技术保障。在设计单片机应用系统时，由于历史的原因，目前在国内仍然以8051系列单片机为主。 …… 此处隐藏：2539字，全部文档内容请下载后查看。喜欢就下载吧 ……