Packet loss detection in networked control systems

One of the main issues related to the reliable operation of network control systems concerns the design of mechanisms able to detect anomalies in the functioning of the communication network through which the control loops are closed. In this article, we address the problem of detecting the occurrence of packet losses and design a mechanism that can detect the occurrence of packet losses directly from process sensor data. Specifically, we propose a moving‐horizon estimation scheme that permits to detect if the packet‐loss rate exceeds prescribed thresholds, which are representative of stability and performance of the control system. We discuss theoretical properties of the proposed solution along with an approximation scheme with reduced computational burden. A numerical example is discussed to substantiate the analysis.     

‘Orthodox’ and ‘alternative’ explanations for the reduction of urban violence in Medellín,Colombia

In 2016, 43 of the 50 most dangerous cities in the world were located in Latin America. In reducing levels of urban violence and preventing future outbreaks, approaches developed in Western Europe and North America are the most influential and have been subjected to considerable testing in high-income urban environments.

This article focuses on Medellín, Colombia. By drawing from qualitative data collected in Medellín, the article scrutinises claims that the social urbanism policies caused the significant reduction in homicides. An alternative explanation for the reduction in homicides is then presented, focusing on the methods of the perpetrators of violence.     

One strike,you're out: the residue of state deregulatory experiments and neoliberal era criminals in a faded Texas boomtown

Both the savings and loans (S&L) crisis of the late 1980s and the more recent subprime mortgage crisis left physical residues in the built landscape of American cities. With the crises, communities that had been the sites of speculative growth became sites of vacant properties, foreclosed properties, unimproved subdivisions, and razed structures. This paper considers the legacy of one such episode of urban development preceding the S&L crisis along Interstate 30 Garland, Texas, where criminals took advantage of deregulation and lax local planning policies to hastily construct a condominium glut. The central argument of the paper is that regional policies fostering outward growth coupled with federal policies stimulating extreme boom and bust cycles have created brief periods in which American Sunbelt communities experience growth pressures, which harnessed incorrectly have created the danger of a ‘one strike, you're out’ scenario: a single chance to succeed or fail.     

Risk assessment of serious crime with fuzzy random theory

This paper presents a novel approach for assessing the potential risk of serious crime events (e.g. terrorist attack). The modelling and assessment of such risk is carried out under uncertain circumstances because of both the randomness and fuzziness inherent in crime data. The approach is based on fuzzy random theory that complements probability theory, with an additional dimension of imprecision. This allows for potential loss caused by a crime to be expressed as a fuzzy random variable. Crime risk is therefore estimated as the mean chance of a fuzzy random event, where the resulting loss reaches a given confidence level. The concept of the average loss per unit of time is also introduced, in order to calculate the rate at which the loss may increase due to possible crime events. The work is compared with typical existing approaches and supported with examples throughout that illustrate its utility.     

步幅鉴定的统计检验

作者自1978年以来与公安系统协作,用概率统计方法定量处理步幅鉴定问题,经反复实践修正,已取得成功。仅河南周口地区公安处,使用这些方法破案,实际案例已有六十多起;并且在全国一些大案要案,如杭州某银行巨款被盗案的侦破中,使用了该方法,本文就是作者八年来这方面科研成果的一部分。     

QoS-Centric Stateful Resource Management in Information Systems

There is little resource management and Quality of Service (QoS) guarantee in the best-effort model underlying existing information systems, leaving information systems vulnerable to exploits and denial-of-service attacks. To overcome these problems, an engineering approach to QoS-centric stateful resource management in information systems is presented in this paper. System engineering principles are first used to identify various scales and levels of resources in information systems. QoS attributes of resources are then discussed. We also introduce the topological and algebraic structures of propagating QoS attributes across levels and scales of various resources for service contracting and admission control. We use a control-theoretic structure to specify QoS-guarantee functions for managing individual resources, including functions of admission control, scheduling & control, QoS conformance monitoring, and state probing and testing, along with scheduling techniques and statistical process control (SPC) techniques to support these functions.     

入侵检测动态取证模型

文章分析了计算机取证的发展情况,指出进行动态取证是其必然的发展趋势。在论证了入侵检测系统用于动态取证的可行性之后,给出了动态取证系统模型,并进行了详尽的阐述。该模型将入侵检测系统与司法分析技术有机结合,它的提出对计算机犯罪的动态取证有一定指导意义。     

打击网络犯罪与相关对策分析

网络给人们带来了惊喜和方便,同时犯罪分子也利用它给人类社会带来危害。近年来,网络犯罪案件呈现出逐渐上升趋势。它不仅严重危害计算机及网络数据和信息安全,而且给社会造成了巨大的经济损失和危害。本文分析了网络犯罪现状和特点,探讨了网络犯罪的手法及打击犯罪的相应对策。     

预防职务犯罪问题的哲学分析

当前的职务犯罪问题严重阻碍着依法治国的进程。文章阐述了职务犯罪的特征，从哲学的角度分析了职务犯罪的原因以及预防职务犯罪作为一项系统工程必须正确认识和处理的几个辨证关系。