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1.
多路视频信号的切换选择处理是多画面视频监控报警系统的重要组成部分,本文主要介绍了多路视频信号切换选择处理的原理及实现录像放像的方法。  相似文献   

2.
视频总线技术是实现多传感器视频资源共享的新概念,它的基本功能是以总线形式传输搜索雷达、跟踪雷达、电视/红外等视频信号,它的基本原理是多路视频信号调制不同的载波,利用频分传输的原理,用一根同轴电缆传输至各显控台,每个显控台解调恢复出这些信号供给综合显示用,这样可以大大减少整个系统视频信号的传输电缆。  相似文献   

3.
详细地介绍了用混频环来实现本振单元的主要思想和具体的电路力,并进行了详细的讲述,主要思想:经过鉴相器的鉴相以后,得到误差信号,经过放大器的放大以后,分成二路到VCO,控制VCO输出信号的频率。一路是高端信号频率,输出二本振信号范围在800.6~798.6MHZ,另一路是低端信号频率,输出二本振信号范围在320.6~318.6MHZ。至于选择哪一路,受计算机输出信号的控制。  相似文献   

4.
[目的]为处理舰船能量管理系统的多个数字量信号,需实时获取并下达多个底层被控电站的指令与状态信号,进而对各个底层控制器的接触器、继电器、断路器及能量链切换开关依次实施有效的控制。[方方法]将STM32F407作为微控制器,设计基于I~2C总线的双级隔离系统,建立高级精简指令集机器(ARM)、I~2C总线与扩展I/O端口芯片的硬件架构。通过软件模拟I~2C总线时序并利用ARM控制器的2个通用端口,可以方便地扩展128路I/O端口并确保I~2C总线的实时性与可靠性。[结果]ARM控制器能够按照既定的能量管理策略对各个底层控制器的I/O端口进行有效、可靠地扩展与实时控制。[结论]在工程应用方面,该I/O端口扩展方法具备一定的推广与参考价值。  相似文献   

5.
论文采用多工器对SRD梳状谱发生器直接滤波的方法,实现倍频器的多路输出。通过实验测量发现,合理选择、设计多工器的带外阻抗,可以有效改善输出信号强度,提高倍频器效率;合理选择偏置电阻值和驱动电感值,可以有效改善倍频器附加相位噪声。利用该方案,已成功将10MHz的信号,倍频为80MHz、90MHz、100MHz、110MHz四路输出信号。  相似文献   

6.
设计一种以串行输入为基础,串并混合方式输出的多路控制系统。  相似文献   

7.
不同于常规航海雷达输出模拟视频信号和触发、艏向、方位等控制信息,IP雷达输出的是网络化的雷达数据。在综合船桥系统应用IP雷达能够实现各分导航设备之间互相备份、互相切换,保证系统的可靠性。对基于DSP和FPGA实现的IP雷达的方案和设计进行论述,并给出了IP雷达的实际应用。  相似文献   

8.
程骏 《船电技术》2015,(11):43-46
为解决重要设备多路电源的快速切换问题,本文将电力电子技术应用到电源切换中,提出了一种大功率的电力电子式电源转换装置,介绍了其结构、原理和设计方法。该装置切换速度可达5ms,功率可达50kW,输出波形稳定,通过仿真和试验,证明了设计原理可行,指标可达到设计要求。  相似文献   

9.
模糊切换型船舶运动PID控制器   总被引:1,自引:0,他引:1  
航向改变时船舶航迹变化过程可以分为瞬态区域和稳态区域。根据不同区域中不同的性能指标,提出了一种把常规PID和TS-PID模糊控制器以模糊切换方式相结合的模糊切换型PID控制方法。该方法集成了常用PID和模糊PID控制方式的优势并弥补了各自的不足,模糊切换方式实现了二种控制器之间的平滑切换。应用钝性定理证明了二阶Nomoto船舶模型的切换型PID控制系统的输入、输出稳定性,并用遗传算法优化控制器参数。与模糊PID控制器的对比仿真实验,表明所提出的方法可以有效提高船舶运动控制的各项性能指标。  相似文献   

10.
电感检测是对润滑油中金属磨粒进行检测的重要手段。为了实现对船舶润滑油中磨粒更高流量、更大尺寸范围的检测,本文提出了一种基于相分复用的双通道电感检测新方法。区别于传统方法,在不牺牲检测灵敏度的情况下,该方法仅利用一路信号输入和一路信号输出就可以完成对两路油液的同时检测。首先阐述了该方法的工作原理,即通过信号复制、移相、信号合成等过程,使两路传感器工作在不同的相位上,实现对两路油液同时检测的功能。在此基础上,搭建了基于相分复用原理的双通道同时检测系统,并在两路传感器内径相同和不同的情况下,以74-88μm的铁颗粒为检测对象,验证了该方法的可行性。传感器内径相同,可保证在相同检测灵敏度条件下提高检测流量,传感器内径不同,可用于不同尺寸范围的磨粒检测。  相似文献   

11.
The subject of port efficiency is one of the important issues facing port authorities and policy makers today. A number of studies have been undertaken which compare ports in terms of their efficiency. But any port comparison can only be valid and meaningful if a port's efficiency is compared with a similar port. The principal objective of this paper is to introduce a systematic approach to identifying similar ports based on the technique of principal component analysis. Secondly, it seeks to identify the most important factors underlying the port classification. Lack of awareness of which factors differentiate ports has resulted in an unnecessary collection of data which are of limited use in port classification. This study has identified three groupings of similar ports within which port comparison can be justifiably made. This approach can be used for any future port comparison and can be applied to other areas of activity facing the same difficulty.  相似文献   

12.
The subject of port efficiency is one of the important issues facing port authorities and policy makers today. A number of studies have been undertaken which compare ports in terms of their efficiency. But any port comparison can only be valid and meaningful if a port's efficiency is compared with a similar port. The principal objective of this paper is to introduce a systematic approach to identifying similar ports based on the technique of principal component analysis. Secondly, it seeks to identify the most important factors underlying the port classification. Lack of awareness of which factors differentiate ports has resulted in an unnecessary collection of data which are of limited use in port classification. This study has identified three groupings of similar ports within which port comparison can be justifiably made. This approach can be used for any future port comparison and can be applied to other areas of activity facing the same difficulty.  相似文献   

13.
If international container ports are to gain a proper appreciation of their various advantages, disadvantages and potential opportunities in a globally competitive environment, it is essential that they conduct effective evaluation of their operational performance. The present study applies five models of data envelopment analysis (DEA) to acquire a variety of complementary information about the operational efficiency of major container ports in the Asia-Pacific region and to identify trends in port efficiency. The study first establishes the causes of inefficiency on the basis of efficiency value analysis. Slack variable analysis is then used to identify potential areas of improvement for inefficient ports. This is followed by the utilization of return to scale analysis to assess whether each port is in a state of increasing, decreasing, or constant return to scale. Finally, a sensitivity analysis is conducted to identify which input or output variables have larger weights in terms of efficiency. The results provide valuable information for port managements in their attempts to establish competitive strategies for the future and to improve their resource utilization for ongoing improvements in operational efficiency.  相似文献   

14.
If international container ports are to gain a proper appreciation of their various advantages, disadvantages and potential opportunities in a globally competitive environment, it is essential that they conduct effective evaluation of their operational performance. The present study applies five models of data envelopment analysis (DEA) to acquire a variety of complementary information about the operational efficiency of major container ports in the Asia-Pacific region and to identify trends in port efficiency. The study first establishes the causes of inefficiency on the basis of efficiency value analysis. Slack variable analysis is then used to identify potential areas of improvement for inefficient ports. This is followed by the utilization of return to scale analysis to assess whether each port is in a state of increasing, decreasing, or constant return to scale. Finally, a sensitivity analysis is conducted to identify which input or output variables have larger weights in terms of efficiency. The results provide valuable information for port managements in their attempts to establish competitive strategies for the future and to improve their resource utilization for ongoing improvements in operational efficiency.  相似文献   

15.
曹阳 《港口科技》2009,(1):35-37
随着港口大型化的发展,各港口的道路信号系统落后是普遍问题。本文分析了港口道路信号控制需求,提出了适用于港口的道路信号系统的系统目标和分级控制结构,并具体地界定了系统管理平台功能和信号控制机功能,最后以天津港为例介绍了港区主干路协调控制的设计方法。  相似文献   

16.
In this paper, the environmental efficiency of the ports is measured. Labour, fund and infrastructure input are selected as the inputs, container throughput, cargo throughput and main business income are selected as the outputs, CO2 emission is chosen as the undesirable output. A new model—RAM-Tobit-RAM (Range Adjusted Measure) with undesirable outputs is built to evaluate the environmental efficiency. Ten Chinese ports from 2004 to 2013 are taken as the samples to verify its rationality. The results suggest that it is not necessarily beneficial for environmental efficiency to expand the port scale.  相似文献   

17.
The paper seeks to improve the evidence base surrounding regional ports and their economic impact. The paper reveals that industries dependent on the port infrastructure are actually key regional players, often operating in relatively fast growth sectors, and contributing to the economic and social needs of the local economy. The focus in the case element of the paper is the operations of Associated British Ports (ABP) plc in industrial South Wales. In examining the direct and indirect consequences of the port activity the paper adopts an input–output framework of analysis. A better contextualization of the economic impact of ports is shown to be necessary in the devolved policy-making environment in the region.  相似文献   

18.
日本濑户内海地区港口和城市发展对日本经济发展作用巨大,是港城协调发展的典型,值得关注和研究。为探究该地区港口与产业发展间的关系,以港口吞吐量和集装箱吞吐量表示地区港口发展状况,以从业人数和产业总产值表示地区产业发展状况,首先基于灰色关联分析法对各县港口与产业发展间的关系进行比较分析,总结归纳发展对策,为辽宁沿海经济带的港口与产业发展提供借鉴。然后,建立兼顾均衡性与功能性的综合评价模型,确定影响濑户内海地区产业发展水平的主要港口指标为港口吞吐量。最后,将其与其它评价模型进行比较,结果表明构建的综合评价模型与现实更吻合,能够更准确地对整个濑户内海地区的港口与产业发展关系进行综合评价研究。  相似文献   

19.
ABSTRACT

Over the years many shipping lines have established terminal operation companies, with some set up as independent firms. However, port authorities and local governments have not always welcomed external investment and control with open arms. The economic implications and each stakeholder’s best strategies remain unclear. This study develops an analytical model in order to study the effects of vertical integration, with a focus on shipping lines’ investment in ports’ capacity. Modelling results suggest that vertical integration between terminal operator and a shipping line leads to higher port capacity, port charge, market output and consumer surplus. It also reduces delay costs. All these results suggest that vertical integration can be an important source of synergy for the maritime industry. Although vertical integration increases the participating carrier’s output at the expenses of non-integrating rival shipping firms, our numerical analysis suggests that the overall social welfare is likely to increase. Preliminary empirical tests confirm that vertically integrated ports handle more traffic volumes and are associated with better infrastructure and equipment. Therefore, port authorities and government regulators should carefully review the market competition status as well as port expansion plans.  相似文献   

20.
This article presents a method of assessing the economic impacts of ports at both regional level and national level, through application of input–output analysis. To this end, a methodology for data collection is proposed, which combines a top-down with a bottom-up approach which should help in surpassing some of the difficulties commonly faced in port economic impact studies. The presented methodology allows port planners and policymakers to assess the economic significance and geographic reach of port investments. This study considers the economic impacts of the port cluster and the socio-economic significance of port user industries. The several layers of the analysis are kept separate to allow a better grasp of direct and indirect impacts. The proposed methodology is demonstrated in a study of the Port of Lisbon, which confirms the significance of this port to the Portuguese economy, and also demonstrates that the influence of the Port of Lisbon is mostly limited to an area in close proximity to the port. Therefore, results suggest that investments for the development of logistic infrastructures associated with the port should concentrate in the immediate hinterland of the port.  相似文献   

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