Trustworthiness Requirements for Manufacturing Cyber-Physical Systems

Distributed manufacturing operations include cyber-physical systems vulnerable to cyber-attacks. Long time not considered a priority, cybersecurity jumped to the forefront of manufacturing concerns due to the need to network together legacy, newer equipment, and entire operation centers. This paper proposes trustworthiness solutions for integrated manufacturing physical-cyber worlds, where trustworthiness is defined to complement system dependability requirements with cybersecurity requirements, such that the resulting manufacturing cyber-physical system delivers services that can justifiably be trusted. Acknowledging the inevitability of cyber-attacks, the paper models the cybersecurity component using the resilient systems framework, where system resilience is viewed as preservation of a required state of cybersecurity

Holonic-based Control System for Automated Material Handling Systems

In real-word manufacturing environments, finding the right job sequences and their associated schedules when resource, precedence, and timing constraints are imposed is a difficult task. For most practical problems classical scheduling easily leads to an exponential growth in the number of possible schedules. Moreover, a decision time period of hours or even minutes is too long. Good solutions are often needed in real-time. The problem becomes even more complicated if changes, such as new orders or resource breakdowns, occur within the manufacturing system. One approach to overcome the challenges of solving classical scheduling problems is the use of distributed schemes such as agent or holonic-based control architectures. This dissertation presents an innovative control architecture that uses the holonic concept, capable of delivering good solutions when applied in dynamic environments. The general holonic control framework presented in this research has specific characteristics not found in others reported so far. Using a modular approach it takes into account all the categories of hardware and software resources of a manufacturing system. Due to its modularity, the holonic control framework can be used for assigning and scheduling different task types, separately o

Architectural and information theoretic perspectives of physical layer intruders for direct sequence spread spectrum systems

In this paper an analysis of physical layer intruders, for direct sequence spread spectrum systems, is presented. Physical layer intruders are traditional jammers that do not have any intelligence as compared to smart jammers that have signal processing capability. The analysis is divided into two domains. In the first domain, different jammer architectures, their computational complexities and performance measurement in terms of bit error rates are explored. In the second domain, information theoretic perspective of jammers is developed. Expressions of channel capacity are developed and compared in the presence and absence of traditional and smart jammers. It is also shown that traditional jammers deteriorate channel capacities but for a smart jammer these can be made independent

Flexible Yagi-Uda antenna for wearable electronic devices

Mechanical flexibility along with size, weight and cost are among the main challenges for future wearable electronic devices. In this paper, the effects of bending on a planar flexible Yagi-Uda antenna operating at WLAN (IEEE 802.11) 5.2 GHz are reported. The flat antenna achieves a relative bandwidth of 13% over which S-11 is less than -10 dB, a realized gain of 8.1 dB, a front-to-back-ratio of 17 dB and a half-power beam width (HPBW) of 89 degrees. The results showed that the antenna maintained the WLAN (5150-5350 MHz) matching bandwidth required under a wide range of bending angles psi(B)