Catching the Bus

<正>I go to school by bus every day.I usually leave home at 6:50 in the morning since the earliest bus leaves at 7:00.One morning when I woke up I found it was nearly 7:00!I took my school bag and rushed out without having breakfast.I ran all the way to the bus stop.When I arrived,the bus was about to leave.I jumped onto the bus right away.I got on the right bus     

A Trip to Qingdao

<正>Last summer,I went to Qingdao with my parents.We took a high-speed rail and after an hour we got to Qingdao.It was a beautiful city.The sky was blue and the air was clean.On the second day after we got to Qingdao,we went to one of the most famous beach1.I was so careless that I lost our camera on the bus.We were very worried,so we got back2the bus station to look for it.To our surprise,we found a young man stand3beside the bus,with our camera in his hand.We were so thankful.     

What a Bad Day!

<正>I had a bad day today.I got up late this morning, so I had no time to have breakfast. I had to run to the bus stop to catch the bus. Then in the first class I couldn't find my English book. I called my father and he said it was still on my table. In the second class, Mr. Yi, the Chinese teacher, asked me to recite the text, but I couldn't. The third class was P. E. We played basketball on the     

You Have Lost Something

<正>This summer,I went on a tour in Liaoning Province.One day,I was taking the bus on my tour to Dalian with many people,when suddenly I felta bit hungry,so I took a banana out of the bag.After I had abanana,I threw the skin out of thewindow without thinking twice.When the driver saw what I have done,he stopped the bus atonce,opened the door,got fromthe bus and picked up the banana skin.When he returned back     

Remember to Start When It's Early

<正>A little boy ran to the bus stop at the full speed at 8 o’clock in the morning.When he got there,he was out of breath.The conductor told the boy the bus had left and he missed it.What~① disappointed the boy was!The conductor said to the boy,"My boy,if you run more fast~②,you can catch the bus.""I’ve already run as fast as possible,"said     

Lucky to Meet My First Class

<正>I have never been late for school,but last Friday I was almost late for class.My alarm clock did not work,and by the time I woke up I found it was 7:30."Hurry up,or you will be late!"said my younger brother."Oh,my God!"I hurried to get up and dashed out of the door without having breakfast.The first class would start at 8:00.It was 30 minutes left.I ran to the bus stop which is not     

Dynamic headway control for high‐frequency bus line based on speed guidance and intersection signal adjustment

To prevent bus bunching, a dynamic headway control method in the V2I (vehicle to infrastructure) environment for a high‐frequency route with bus lane is developed. Bus operating speed guidance on the mid‐blocks and intersection signal adjustment are two main strategies in the proposed method. A forecasting model of bus travel time under the dynamic control method is developed. The objective function is set up by taking into account differences between actual bus headways and dispatching headways, and the scaling ratios of intersection cycle lengths. The optimization model is solved using genetic algorithm. The proposed method is applied to a real bus route in Meihekou city, China, and compared with the current control plan as well as holding strategy. Results show that the proposed method can reduce bus headway deviations in all investigating periods; negative impacts on cars can be limited by setting reasonable values for the parameters.     

小区电梯集中监控系统的开发

介绍了一种使用现场总线技术构建的小区电梯集中监控系统,利用微处理器的串/并行接口采集电梯信息,采用CAN总线串行通信技术,通过小区底层通信控制网络与监控中心进行数据传输.     

Subsidies and welfare maximization tradeoffs in bus transit systems

Under a maximum welfare objective, a fixed route bus system and a flexible route bus system are optimized subject to various financial constraints. For each bus system, the decision variables including fare, headway, route spacing, and service zone area are optimally solved to analyze unconstrained, break-even and subsidy cases. Numerical results and sensitivity analysis are presented in the paper. From the numerical evaluation, it is shown that the effects of subsidies on welfare are quite different for a fixed route bus system versus a flexible route bus system. For the fixed route bus system, the optimal welfare curve is very flat over a wide range of subsidies. However, for the flexible route bus system, the break-even constraint causes a large loss in the social welfare. Thus, with the welfare maximization objective, the break-even policy or low transit subsidy policy may be preferable for the fixed route bus system, but not for the flexible route bus system. The results derived from this study can support effective decision-making on bus transit systems in areas that may experience significant shifts in residential density, as well as geographic or physical changes in their street networks. This paper was presented at the 46th annual meeting of Western Regional Science Association in Newport Beach, California, 21–24 February 2007.     

A Visit to Qingdao

<正>I went on a visit to Qingdao with my parents this summer.It is a beautiful city with so many places to visit.But what impressed me most was Lao Mountain.I got up early that morning.It took us about an hour to get to~1 there by bus.Then