The use of GIS and relational database management systems to improve the scheduling operations of paratransit

The scheduling operations of many paratransit agencies in the United States are undertaken manually. Those customers who are eligible to travel call in their requests the day before the trip is needed. As the trip requests are received, they are entered into a list of unscheduled trips. In order to schedule these trips, the scheduler must first determine the number of drivers and shuttle buses that are available as well as the time of availability of each. The scheduler must then try to match the rides that are in “similar” areas around the “same” time to place together on the driver's schedule. As new trip requests are made, the schedulers must adjust the trips that are already scheduled to try and schedule as many trips as possible in the most efficient way.

By developing a system that would improve the scheduling system operations of, in this case, DART (Delaware Administration for Regional Transit) First State Paratransit, customers can expect to receive better service that will improve their ability to travel throughout the community. Some devices that could also improve the operations of paratransit agencies are described in this paper, such as satellite‐based Global Positioning System (GPS), radio communication systems, mobile computers, radio frequency‐based data communication systems, internet web pages, automated paratransit information systems, and card‐based data storage and transfer media. However, because paratransit systems are difficult to operate cost‐efficiently, the optimum and most cost‐efficient device must be selected. The system chosen for DART First State Paratransit includes the use of a relational database management system (RDMS) and a transportation Geographic Information System (GIS). RDMS keeps track of the database information as well as the scheduled trips and the GIS is ideal for analyzing both geographic and temporal data. This system is shown to be superior to the manual system.     

数据链信息系统准确性效能评估模型分析

数据链信息系统是军队信息化建设的核心与支柱,是实现多军种联合作战的纽带,是支持平台作战向网络中心战转变的关键。文章分析了数据链信息系统准确性效能涉及的因素,确定了数据链信息系统准确性效能评估的基准,建立了数据链信息系统准确性效能评估数学模型。     

The effectiveness and costs of speed reductions on emissions from international shipping

Greenhouse gas emissions from international shipping are an increasing concern. The paper evaluates whether vessel speed reduction can be a potentially cost-effective CO₂ mitigation option for ships calling on US ports. By applying a profit-maximizing equation to estimate route-specific, economically-efficient speeds, we explore policy impacts of a fuel tax and a speed reduction mandate on CO₂ emissions. The profit-maximizing function incorporates opportunity costs associated with speed reduction that go unobserved in more traditional marginal abatement cost analyses. We find that a fuel tax of about $150/ton fuel will lead to average speed-related CO₂ reductions of about 20–30%. Moreover, a speed reduction mandate targeted to achieve 20% CO₂ reduction in the container fleet costs between $30 and $200 per ton CO₂ abated, depending on how the fleet responds to a speed reduction mandate.     

新机作战雷达保障引导效能模糊综合评价

结合新机作战雷达保障引导各因素的分析,提出了雷达保障引导效能评价指标体系,建立了二级模糊评判模型,确定了各因素的权重和综合效能评定原则,运用模糊综合评价的方法,通过实例对新机作战雷达保障引导效能进行了量化评估。     

基于OPN的舰载对空搜索雷达作战效能仿真分析

舰载对空搜索雷达的作战效能评估是电子战领域的一个研究热点,它的评估方法得到了广泛的研究.针对通常的模型不能同时描述舰载对空搜索雷达作战系统的静态结构和动态过程,采用对象Petri网建立了舰载对空搜索雷达作战系统的模型.首先在对舰载对空搜索雷达作战系统分析的基础上,设计了系统对象类,并运用OPDL语言对各个对象类和舰载对空搜索雷达作战过程进行了描述;然后选取了效能评估指标;最后利用所建立的OPN模型进行了仿真,通过仿真运行对不同对抗环境下舰载对空搜索雷达的效能进行了分析,仿真结果与实际相符合.     

基于船舶转矩测试的某小型运输船机桨匹配分析

文章基于船舶转矩测试分析小型船机桨匹配状态的方法,通过某小型港口运输船的实际运用,论证了该方法的有效性和可操作性,为中小型船舶或老旧船舶的机桨匹配提供了参考。     

舰炮弹药对典型舰船目标毁伤效能研究

研究舰炮弹药对典型舰船目标毁伤效能的分析模型及评估方法.建立典型舰船目标功能易损性模型,通过分析舰炮弹药对舰船的毁伤特性,提出可用于计算的重度和中度毁伤判定标准.给出舰炮弹药内爆炸对舱室的毁伤概率计算方法,应用Monte-Carlo方法建立毁伤效能计算模型,编写程序并进行实例计算.结果 表明在一定的毁伤等级下,瞄准点设...     

高职合作教学改革试验的调查分析与改进对策

文中主要采用问卷调查方式,就高职学生对合作教学的认知、态度和作用等问题进行调查,认为合作教学是一种有利于活跃课堂气氛、促进学生关键能力发展、提高高职教育教学质量的教学组织形式。     

一种提高舰艇编队质心干扰效果的方法研究

质心干扰是水面舰艇对抗反舰导弹的一种重要手段。文章分析了编队条件下质心干扰存在的问题,提出了采用“二次质心干扰”提高编队质心干扰效果的方法,通过仿真说明了方法的有效性。     

一种基于SEA方法的舰艇防空作战电子对抗作战效能评估模型研究

文章运用SEA方法对舰载电子对抗作战构建了一个效能评估模型,并对评估参数提供了量化分析工具。利用实例计算对评估参数进行了分析,对电子对抗作战提出了参考意见。