Short-term scheduling of crude oil operations in refinery with high-fusion-point oil and two transportation pipelines

In some refineries, storage tanks are located at two different sites, one for low-fusion-point crude oil and the other for high one. Two pipelines are used to transport different oil types. Due to the constraints resulting from the high-fusion-point oil transportation, it is challenging to schedule such a system. This work studies the scheduling problem from a control-theoretic perspective. It proposes to use a hybrid Petri net method to model the system. It then finds the schedulability conditions by analysing the dynamic behaviour of the net model. Next, it proposes an efficient scheduling method to minimize the cost of high-fusion-point oil transportation. Finally, it gives a complex industrial case study to show its application.     

Resource conflict detection and removal strategy for nondeterministic emergency response processes using Petri nets

Correctness of an emergency response process specification is critical to emergency mission success. Therefore, errors in the specification should be detected and corrected at build-time. In this paper, we propose a resource conflict detection approach and removal strategy for emergency response processes constrained by resources and time. In this kind of emergency response process, there are two timing functions representing the minimum and maximum execution time for each activity, respectively, and many activities require resources to be executed. Based on the RT_ERP_Net, the earliest time to start each activity and the ideal execution time of the process can be obtained. To detect and remove the resource conflicts in the process, the conflict detection algorithms and a priority-activity-first resolution strategy are given. In this way, real execution time for each activity is obtained and a conflict-free RT_ERP_Net is constructed by adding virtual activities. By experiments, it is proved that the resolution strategy proposed can shorten the execution time of the whole process to a great degree.     

Strengthening the Global Financial Safety Net: Challenges and Prospects

The paper shares the idea on the current global financial circumstance; whereas rapid financial globalization was a basic source of the systemic risks of the global financial crisis, the world economy is even more integrated in the aftermath of the global crisis. It emphasizes the importance of the global community to strengthening the GFSN to respond to a crisis. Kim argues that the GFSN should be a multi-layered structure, and only a single layer alone would not be sufficient to handle the global crisis due to its impact of economic damage. More specifically, the paper suggests a multi-layered structure of the GFSN as follows: self-insurance with foreign exchange reserves, bilateral currency swaps by central banks, RFAs already influencing regional financial recourse and stability in several regions, and global arrangements, such as the IMF facilities.     

基于电缆网时域反射信号检测与预处理技术研究

运行电缆网时域反射信号检测与预处理技术研究。应用小波分析变换电缆网时域反射信号的奇异点进行检测与预处理误差较大,采用小波分析的反射波消噪技术提出一种小波分析最优分解层数的自适应确定函数算法。     

Coloured Logic Petri Nets and analysis of their reachable trees

Logic Petri nets (LPNs) can describe and analyse the batch processing function and passing value indeterminacy in cooperative systems, and alleviate the state space explosion problem. However, the indeterminate data of logical output transitions cannot be described explicitly in LPNs. Therefore, Coloured Logic Petri nets (CLPNs) are defined in this paper. It can determine the indeterminate data of logic output transitions in LPNs, i.e., the indeterminate data can be represented definitely in CLPNs. A vector matching method is proposed to judge the enabling transitions and analyse CLPNs. From the marking equation and the proposed reachable tree generation algorithm of CLPNs, a reachable tree can be built, and reachable markings are calculated. The advantage of CLPNs can be shown based on the number of leaf nodes of the reachability tree, and CLPNs can solve the indeterminate data of logical output transitions. Finally, an example shows that CLPNs can further reduce the dimensionality of reachable markings.     

基于时间Petri网的生鲜肉冷链物流流程建模研究

以生鲜肉冷链物流为例,应用时间Petri网理论对冷链物流流程建模,研究冷链物流运作效率。用CPN tools对建立的模型运行后得到各环节的性能指标,发现流程中所存在的不足。最后提出对流程的改进建议。建模方法对复杂的冷链物流流程的建模和仿真有一定的参考价值,并为冷链物流以后的优化研究提供了新的思路。     

大断面、联合支护技术在软岩巷道中的应用

平煤股份六矿二水平-440大巷为软岩巷道,围岩松散破碎,围岩主要以泥岩、沙质泥岩为主,为满足矿井发展需要对-440大巷进行大断面扩修。在分析了巷道岩性的基础上,提出了锚、网、索+喷浆+注浆+注浆锚索联合支护的施工方案,并进行了工业性试验。试验表明,该技术支护效果良好,并取得可观的经济效益。     

基于“智慧城市”的武汉市中小企业供应链创新研究

文章基于武汉市“智慧城市”建设的基本方针,结合物联网技术和BRP,构建“智慧／物联网-BPR”供应链业务优化模型。并通过对武汉市中小企业的供应链进行创新研究,建立智慧供应链,从而提高中小企业的核心竞争力．推动武汉“智慧城市”的进程。     

时间Petri网在项目进度管理建模中的应用

通过分析现有时延Petri网和时间Petri网在项目进度管理仿真模型的不足,提出基于库所时间约束Petri网的项目进度管理模型,该模型具备全局时钟特性,不仅能体现工序自身时间参数,同时能对外部资源等工序外延时间约束进行建模。实例仿真结果表明该模型的有效性。     

一种高安全性的电子商务解决方案

通过对电子商务解决方案中的关键技术的初步探讨,针对电子商务的安全性问题的解决提出了一种新的解决方案;它可以通过计算机技术和非计算机技术两个方面的手段来增强系统的安全性,这是在电子商务解决方案中的一种有效尝试.该方案具有较强的可操作性,可以推动电子商务技术的发展.