1 Introduction

Currently,the social economy has entered a new period of rapid development in China,the major contradiction is the relationship of the rapid growth of urban car ownership and the slow growth of road construction.Then,a series of traffic problems are triggered such as environmental pollution,traffic safety,transportation energy consumption etc.One of the most prominent problem is the urban traffic congestion and its negative impact.To control the urban traffic congestion,one must find the evolution rules of traffic congestion and dynamic motion law of traffic flow.Moreover the integrated structure of induction-control and evaluation must be established.

The information of the urban intelligent transportation system(ITS)generated in traffic network is sent to travelers,the travelers can select the best route for themselves.The induced information can balance the traffic flow on time and space aspect,which make the traffic system more efficient in the whole urban traffic network.

专业知识及专业技能的考核评分,合格(60分)。护理质量、满意度的评分均选用问卷调查的方法进行,每个项目分为5个等级,分数为1至5分,满意评价:不满意、满意、非常满意。满意度=(非常满意+满意)例/%。发放的问卷共计200分,回收率100%。

Traffic information induced model has been studied based on game theory[1−2]and fuzzy clustering theory.[3]Some scholars proposed the intelligent algorithm based models[4−5]and analyzed the effect of vehicle behavior on the network.[6−7]Considering the real traffic in China,local scholars proposed some methods of the Locating VMS(Variable message signs)under ATIS(Advanced traveler information system)environment.[8−14]Other scholars have studied traffic demand,traffic supply,and simulation technology.[15−24]In particular,the team of Ben-Akiva made a lot of outstanding achievements.In these studies,the purpose of traffic control is to relieve network congestion.However,most of the existing methods have not fully demonstrated the effectiveness.Meanwhile,the previous studies only focus on homogeneous traffic flow.Unfortunately,those method cannot solve the traffic problem in China due to mixed traffic flow leads to more complex traffic phenomenon.Then,a new method is needed to relieve traffic congestion based on dynamic traffic information.

In this paper,the mesoscopic traffic simulator is designed firstly which can generate the real-time traffic prediction information.However,the information do not immediately be sent directly to users on the network.In contrast,the information is sent to the “virtual” users of the mesoscopic traffic simulators.Then,the user’s behavior responded to the information can be modeled based on the choice model.At the same time,the simulator can obtain the operation condition of the road network by the virtual user experience.If the actual condition does not be consistent with the simulated condition,a set of algorithms are used to correct the predict road conditions and continuous iteration until the virtual users “satisfaction”in simulator.At this point,the only officially traffic forecast information is released to the real-world users on the network.In other words,the actual released information is “foresight”,it is generated based on the response of the travelers for the forecast information.

2 The Mesoscopic Traffic Simulator

The mesoscopic traffic simulator needs to ensure the accuracy and the efficiency of the calculation.[25−29]In other words,the simulator not only meets the requirement of the accuracy in simulation but also takes into account the requirement of running speed in order to the real-time online application.In the simulator,the key technology is the mathematical models including road network model,static queuing model,velocity model,and vehicle movement model.

2.1 The Road Network Model

The road network model is used to describe the composition of the urban road network,which mainly consisted of node,connected line,line group,line,detectors,turning prohibition line,signal control equipment,traffic zones and so on.The urban road network topology is composition of nodes and connected lines,as shown in Figs.1–2.VMS is Variable Message Signs and VSLS refers to the variable limit speed system.

Fig.1 Road network topology.

Fig.2 The relationship between network elements.

2.2 The Deterministic Queuing Model

The deterministic queuing model describes queuing behavior of vehicles at the intersection including the vehicles into the queuing,moving in the queue and leaving the queue.The queuing delay of the i-th vehicle in the queue is:

where c is the output capacity of the lane group.During a period of time t,there are ct vehicles leaving the queue.If a moving vehicle reaches the end of the queue at time t,its position(and,therefore,the position of the end of the queue)will be

where q(0)is the end position of the queue at time t=0;lcar=1/ρjamis the average length of vehicles including headways;Normally,the truck and bus can be converted to the standard car;ρjamis jam density;m is the number of moving vehicles between the considered vehicle and the queue at time t=0;

Note that there are three cases:when 0

The case q(t)<0 will never occur.

The case q(t)>L means that the queue is already dissipated when the vehicles reached the end of the segment.

2.3 The Anisotropic Mesoscopic Simulation Model

After an advanced time period,some of the vehicles would be changed the original path.The network states will be changed.This information is passed to the route choice model,and then goes to the steps(ii);

Fig.3 The relationship between network elements.

A moving vehicle’s speed is determined by the traffic density within the SIR and calculated by k-v relational model.As shown in Fig.3(a),the first case is the consistent physical property of road,the SIR density is:

游学类教材的整体层次、结构和形式水准需与时俱进。教材呈现形式,表现在印装质量、插图、配套资源、数字产品等多个方面。游学类教材必须与对外汉语的语言学习类教辅有所区别，体验和沉浸较之于语言学习应给予更多的重视。教材在媒介的选取、视听的传达、版面的安排和风格等各类形式中，须体现多元媒介的呈现模式，在形式水准和整体层次中提升效果和境界。

where n is a number of lanes in SIR;is the vehicle number in SIR at time t−1 for a vehicle i;l is the length of SIR.In the cases of Figs.3(b)and 3(c),the density is calculated by the following equation:

where kjamis the jam density of the segment.The current speed of one vehicle i is obtained by the following exponential function:

is the speed of the vehicle i at time t;is the free flow speed on the segment;vminis minimum speed;α,β are model parameters.The speed-density relation model as the following Fig.4.

Fig.4 Speed-density curve in SIR.

2.4 The Vehicle Movement Model

The model describes the vehicle’s movement on the segment.In the case of no queuing,when time t=0,the vehicle located at z0,then when the vehicle reaches z the time is t(z),the relationship is as follows:

where λ is determined by the following equation:vdis the downstream speed on the segment;vuis the upstream speed on the segment;Lsis the length of segment s.In case of t=0,the vehicle at position z0,then the vehicle’s positon at time t is:

As shown in Fig.6,there are 3 paths between origin and destination in the traffic network.The path travel are all T.The overlap part travel time in path 1and path 2 is T-d.In MNL model,the probability of each selected path is 1/3,obviously it is right if and only if T=d which means there are not any overlap parts.Figure 7 describes the function relationship between the choice probability and the no overlapping part of path 1,2(d/T).When the ratio is close to 0,the path 1,2 becomes one physical path.At this time,the probability of a traveler select path 1,2 is 50%,and the probability of choice path 3 is also 50%.The PSL model can correctly reflect this kind of expectation.But the MNL model gives the probability of 33%,which is not sensitive to the overlap of the path.

If there is a queue when the vehicle reaches the position z(t),then z(t)is determined by the following equation at any time t:

The traffic network is built including geometry characteristics and network topology.The time length is defined.All the vehicles are loaded on the current location on the network at time t=0.The update counter is 0,namely j=0.

本工程涌水量大、水位降深大，所需水泵扬程高，水泵的外径一般为250 mm。而井管内径至少需大于水泵外径50 mm，故本次管内径按400 mm考虑，成孔直径按700 mm进行实施。采用6 mm厚钢管，滤管为桥式滤水管，滤管仅设置在粘土层中，防止抽取上部1～3卵石层地下水；滤管外包40目锦纶滤网，采用瓜子片滤料回填至滤管顶部以上，其上回填粘土球止水，防止1～3卵石层地下水进入降水井，详见图3。

The detailed algorithm is as follows:

图4显示了RPL-FAHP、0.8×ETX+0.2×RE和0.6×HC+0.4×RE在不同节点密度下的平均端到端时延。可见在不同节点密度下RPL-FAHP的平均端到端时延均明显低于0.8×ETX+0.2×RE和0.6×HC+0.4×RE。表明RPL-FAHP可明显降低网络时延。

3 The Predicted Information Induction Strategy

The most of traffic information guidance strategies are based on current traffic situation or posted information which is not sufficient to describe the time varying traffic network conditions.It is a kind of passive control strategy.It maybe cause overreaction for the information which can result in the opposite effect.One of the answers is to predict the traffic situation based on the current traffic information.So the predicted information can be put into the mesoscopic traffic simulator,which can simulate the traveler’s response to it.And then the content of information is adjusted until the information tends to be stable.After several cycles the unbiasedness and consistency[30]strategy can be acquired.

今人读荀子《劝学》，最喜欢讲的是：“青，取之于蓝，而青于蓝；冰，水为之，而寒于水”，总是梦想超过老师，却很少提及同文中的“不登高山，不知天之高也；不临深溪，不知地之厚也；不闻先王之遗言，不知学问之大也”之句，其实荀子早就预见到后辈学生的骄狂。

3.1 The Traffic Guidance Theory Based on Predicted Information

The theoretical framework is shown in Fig.5 based on predicted information.The traffic guidance strategy is proposed by the current network conditions.It is the dynamic induced information and can be sent to the virtual users on the network(travelers).The latter simulates the behavior of the traveler response for the information by the choice model.And then the new traffic guidance information can be proposed according to the different response of traveler.Continue to the cycle until the network has a consistent state,at this time the latest strategy can be sent to the real traveler.The continuous average algorithm is used to solve this kind of consistency problem.

The consistency criterion is the path impedance(travel time)in the cycle.The updated algorithm of impedances is as follows:[31]

where k is the number of the cycle;l is the path;h is the time interval;is the average travel time;is vehicle travel time in supply simulator;λkis weight,λk=1/(k+1)in continuous average algorithm.Given a very small number ε>0,if||−||<ε,the algorithm is over,otherwise return to the fi rst step until k is equal to the designed number K.The outputted fi nal strategy is consistent.skis defined as consistency measure;is induced information.The following equation can be founded.

In above equation,the proposed guidance information is the best one when skis the minimum.It can be sent to the travelers in the real network.

Fig.5 Traffic guidance based on predicted information.

3.2 The Corresponding of Travelers for Dynamic Traffic Information

The weather forecast will not change the weather condition. But the traffic prediction information maybe change the future condition of traffic network.When the published induced information by various channels,some travelers will follow the induction but the others will not that make the road congestion occurs.So this information may be inaccurate which is called the overreaction.Fortunately,a feasible method is to obtain the consistent information from the mesoscopic simulator.The proposed strategy is sent to the simulator firstly,and then the behavior of travelers is simulated.The strategy will be adjusted by the simulator information.It is worth noting that the response behavior model of dynamic induced information is very important.

Most of dynamic traffic guidance information are received by VMS,radio station,mobile phones,vehicle terminal and so on.Usually,there are three types guidance information:the descriptive information,the guidance information and no information.No information is very simple.It means no any information.The travelers select path according their own preferences.The guidance information recommend the path to traveler directly.The descriptive information is more complex.The kind of information is just describe the current network status and the travelers choose the most advantageous path by judging their own behavior.In this paper,the descriptive information are adopted for mathematical model.

3.3 The Traveler Behavior Model on Road

In this paper,the Logit path-size(PSL)model and the multinomial logit model(MNL)model are used to describe the behavior of traveler to dynamic information which proposed by Ben-Akiva.[32]

2016年，重庆市政府下发通知，制定2015-2017年的煤矿关闭工作目标，确定了煤矿关闭退出走向。2017年，重庆市政府下发《重庆市人民政府关于印发2017年全市安全生产工作要点的通知》，明确规定：“关闭金属非金属小型矿山100个。②”再一次强调政策性关闭煤矿的工作。2017年3月29日，M煤矿根据重庆市政府下达文件中的关闭要求，正式开始煤矿关闭和职工安置工作。

The utility of overlapping paths are corrected by path size(PS)between starting and ending points.PS is derived from the discrete choice theory.The team is defined as follows:

高文军[4]等认为超声引导下穿刺活检方便、简单、安全、准确，在严格掌握适应证的情况下，可以用于卵巢癌的诊断及鉴别诊断。本研究在超声引导下穿刺活检中有6例穿刺病例病理提示：无法诊断（组织量少或坏死物），并将这6例归为阴性。其中有2例术后证实为畸胎瘤，4例术后证实为恶性卵巢肿瘤。回归分析：这6例盆腔肿块内部回声均以囊性成分为主，肿块较大，穿刺物为：坏死物或纤维组织，存在假阴性。

where Γiis link sets on path;lα is travel time of road α;Liis total travel time on path i;cnis the path selection set for the traveler n,δαjis a 0-1 variable,if the road α in the path j,then it is 1,otherwise it is 0.The travel time of the traffic flow is calculated by PS,in generally,it is static which descript the perception time for overlapping paths.If there is no overlap path,the PS=1,otherwise PS<1.So as long as the PS attributes are defined,the utility of traveler n select path i can be expressed as:

The path selected probability Pn(i)is as follow:

对于成熟的、有一定规模的商圈而言,移动应用不可或缺。作为商圈信息展示的网上门户，商业推广和客户服务是移动APP的主要功能。WIFI和4G网络的普及使得相关应用软件的下载更加便捷。依托微信平台的企业公众号开发和小程序应用能提高用户的体验，在系统设计建设过程中可考虑先设计APP，再向其他平台扩展。APP要以轻量级为主，主要体现出商圈的特色服务和货品的分区、分类。

Fig.6 The problem of path overlap.

Fig.7 The overlapping path selection probabilities.

4 The Mesoscopic Traffic Simulation

The simulation period can be divided into two phases:the update phase and the advance phase.In update phase,the traffic dynamics parameters(e.g.densities,speeds)are updated.In advance phase,the vehicles will be advanced to new position according to dynamic traffic flow model.Generally speaking,advance phase is far less than the update phase.There is relation as the followed equation.

where∆tupdateis the updated time interval;tadvanceis the advanced time interval;T is simulation time;kUand kA are integers.A closed cycle scheme is used to solve the problem of simulation(see Fig.8).

研究会广泛联络且积极组织社会各界力量，与国内外的智囊机构、研究团体形成了长期良好的合作关系，有数百名知名的专家学者领导和参加有关研究活动，形成了特有的系统工程研究人才库。钱学森、宋健、蒋正华、李忠凡、马俊如、孔德涌、于景元、景天魁等老一辈的系统工程专家、经济学和社会学家、人口专家都对研究会会的工作给予过重要的指导和帮助，自20世纪80年代成立以来，研究会的专家学者为党中央和国务院提供了几十份建议等报告，受到中央领导的高度重视。承担国务院及有关部委委托的研究课题和国家软科学重点攻关项目几百项，多次获得国家科技进步一、二、三等奖。

where q0,l,c,m are defined as mentioned.

(ii)Simulation cycles

扩展卡尔曼滤波具有抑制滤波器发散的作用,滤波计算中,在利用量测不断修正预测值的同时,也对未知或者不确切的系统模型参数和噪声统计进行参数估计和修正。所以本文中的连续过程噪声方程为:

(i)Initialize

At current time interval,the traffic flow parameters will be updated firstly and the counter plus 1:j=j+1;The parameters include dynamic OD flow,dynamic network status,lane group capacity,control strategy,incidents and work zone(location,duration,severity and so on).

Fig.8 The mesoscopic traffic simulation.

(iii)Information corresponding

The anisotropic mesoscopic simulation(AMS)model means that at any time,a vehicle’s prevailing speed is influenced only by the vehicles in front of it,including those that are in the same or adjacent lanes and the influence of traffic downstream upon a vehicle decreases with increased distance.So,the velocity of the moving vehicle can be determined by the traffic density in a certain area in front of it.The area is known as speed influencing region(SIR)as shown in Fig.3.

◆甚至出版社也不例外，刚刚听到某大学出版社的社长介绍：规模不大的该社，已实现“日出图书三到四种，其中既有自然科学各领域的专门之作，也有大量的人文社科类丛书.”值此，便会想起一位日本同道的话：你们出了那么多科学史的书，不看怕遗漏了什么新的发现；但费尽气力好不容易买到、阅后，却一无所获.

快速心房纤颤是心脏急症,快速心房纤颤如持续时间过长可引起血流的动力学异常导致心功能下降,增加患者病情,增加住院率及死亡率,和肽素是前精氨酸加压素的羧基肽,克服了精氨酸加压素在临床检测方面的劣势,结果稳定、灵敏度高且保存时间长,最近国内外在临床心衰、心肌梗死中进行了大量研究。本研究对快速房颤患者并结合临床数据进行分析,旨在探讨心房纤颤患者血液中和肽素水平与房颤快速房颤心衰的相关性。

(iv)Simulation termination criteria

All the updated phases are performed,the algorithm is terminated when j=kU.The following information can be got by simulation:(i)The origin and destination of a car;(ii)The travel time of a car;(iii)The average speed,density and flow on a link;(iv)Queue length within a period of time.

5 Case Study

Daizong street of Tai’an city in Shandong province,China,there are 7 signal-controlled intersections.It is about 1.68 km long.In this study,the effect of dynamic information inducing strategy to relieve traffic congestion and improve traffic condition are studied.Therefore,the signal control is not considered and the intersection is taken the form of the no signal control.Network structure and related data are derived from the actual survey,as shown in Fig.9 and Table 1.

Fig.9 Road network of Daizong street.

In this paper,urban road network is studied,the free flow speed of road is defined as 60 km/h.ρjamis 0.1150,α is 1.9420,β is 0.5040,SIR length is 150 m.The simulation time is two hours,and it is divided into 8 time periods of 15 minutes.In each small time period,the vehicles are loaded according to the OD table,which calculated by traffic flow.In the first 15 minutes,the OD demand is loaded on the network and then the dynamic demand of the next 15 minutes until the simulation is completed.

The algorithm will produce traffic information according to road condition and release to the traveler.The information published cycle is 300 seconds.The travelers choose the best travel mode path and start time according to the information based on behavior choice model.At the same time,the vehicles change the path to avoid the congested section according to the dynamic induced information.

From the macro perspective,there are 38177 vehicles loaded on the network in the simulation time with dynamic information and without information.It means that the demand are all loaded on the network and the vehicles can move on link with some rules.The maximum number of vehicle on the network at the same time occurs in the seventh time periods.At this period,the number of vehicles on the network is 701 without dynamic information and 724 with it,which shows that some vehicle move quickly and more demand be loaded into the network.The total density in whole simulation time is 2.8755 without dynamic information and is 2.8942 with it.The average density is decreased slightly,which means the induced information can be partially balanced network traffic flow and can smooth congestion.The total velocity in whole simulation time is 3.0991e+003without dynamic information and is 3.1068e+003with it.It can be seen that the average speed is increased when the travelers received the dynamic information.This is due to that there is no more congested section,the average speed is calculated by speed-density model.The network average density is more smooth and the speed is more quickly.

The results show that the average travel delay is reduced by 8.7%in whole simulation time period,as shown in Figs.10 and 11.

山药的病害主要有炭疽病和褐斑病，高温多雨季节尤为严重，主要危害山药的叶片和藤蔓，造成提前落叶甚至植株枯死，导致减产。防治方法：整修好田间套沟，达到沟沟相通，雨停田干的要求；控制氮肥的施肥次数和施肥量；药剂防治，从6月中旬开始喷药防治，每隔10天左右喷一次，共喷6-8次。药剂选用70%的甲基托布津可湿性粉剂700倍液，确保山药稳产高产。

Fig.1 0 The impedance of some sections before information induction.

In order to show the effectiveness of the induced information,the average traffic flow,average density and average velocity with information and no information on each section are counted out.Figures 12–17 showed the network status with dynamic information and without information.The figures described the detailed the average flow,the average density and average speed of each segment in each time period.

From the mentioned time and space figures,the average density has some smoothness in different degree,which means some vehicles changed the original path according to the induced information.Because of some sections have a great congestion,some travelers selected a relative smooth one.

Fig.1 1 The impedance of some sections after information induction.

Fig.1 2 Density on each link per interval without information.

Fig.1 3 Flow on each link without information per interval.

Fig.1 4 Speed on each link per interval with information.

Fig.1 5 Density on each link with information per interval.

Fig.1 6 Flow on each link per intervaln with information.

When the dynamic induced information is published,the average speed has been significantly improved,the total traffic flow was relatively large,which show that the traffic region has become better.Another words,the dynamic induced information can be effectively to ease and control the traffic congestion.

Fig.1 7 Speed on each link with information per interval.

6 Conclusion

In this paper,the improved mesoscopic traffic flow simulation model is proposed.The traffic information is integrated into the behavior model of traveler,which reflect the response of the vehicle to the traffic information.The propagation process of vehicles in the network can be described more realistic than existing model.A dynamic traffic information generation algorithm is designed by using the idea of consistency.Furthermore,a case study is carried out on the Daizong street of Taian city by using the published dynamic traffic information.The research results show that the proposed method can improve the traffic environment,alleviate traffic congestion in a certain way in this paper.The generated information is dynamic and real-time traffic information.If it is able to predict the traffic situation and achieve a certain degree of accuracy,the forecast of traffic guidance information will play a more important role in the actual application,which is also the hot issue of traffic transportation in the future.

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