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Abstract-Critical infrastructures and industrial control systems are complex Cyber-Physical Systems (CPS). To ensure reliable operations of such systems, comprehensive threat modeling during system design and validation is of paramount significance. Previous works in literature mostly focus on safety, risks and hazards in CPS but lack effective threat modeling necessary to eliminate cyber vulnerabilities. Further, impact of cyber attacks on physical processes is not fully understood. This paper presents a comprehensive threat modeling framework for CPS using STRIDE, a systematic approach for ensuring system security at the component level. This paper first devises a feasible and effective methodology for applying STRIDE and then demonstrates it against a real synchrophasor-based synchronous islanding testbed in the laboratory. It investigates (i) what threat types could emerge in each system component based on the security properties lacking, and (ii) how a vulnerability in a system component risks the entire system security. The paper identifies that STRIDE is a light-weight and effective threat modeling methodology for CPS that simplifies the task for security analysts to identify vulnerabilities and plan appropriate component level security measures at the system design stage.

This paper presents a new technique for the detection of islanding conditions in electrical power systems. This problem is especially prevalent in systems with significant penetrations of distributed renewable generation. The proposed technique is based on the application of principal component analysis (PCA) to data sets of wide-area frequency measurements, recorded by phasor measurement units. The PCA approach was able to detect islanding accurately and quickly when compared with conventional RoCoF techniques, as well as with the frequency difference and change of angle difference methods recently proposed in the literature. The reliability and accuracy of the proposed PCA approach is demonstrated using a number of test cases, which consider both islanding and non-islanding events. The test cases are based on real data, recorded from several phasor measurement units located in the UK power system.

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I3C NMR spectra were obtained for polymers made by ring-opening polymerization of cyclopentene and bicyclo[2.2.l]hept-2-ene respectively. The fraction of cis double bonds could be determined with much greater precision from I3C NMR spectra than from IR spectra and varied from 0,66 to 0,31 for the samples of poly(1-pentenylene), (2), and from 1,0 to 0,14 for the samples of poly(l,3-~yclopentylenevinylene), (4). This is the first time an all-cis polymer of 4 has been reported.The spectra of 2 showed a cis (upfield) and trans (downfield) peak for each of =CH and s(-CH2, but only one peak for /3-CH2. The spectra of 4 showed multiple fine structure, the main splittings corresponding to a cis (upfield) and trans (downfield) peak for s(-CH, and a reverse line order for the other three carbons; subsidiary splittings were observed for all but the olefinic carbons, interpreted in terms of sensitivity of the chemical shifts to the &/trans structure at the next nearest double bond. A complete interpretation of the line orders in 4 is given in terms of steric compression effects. The possibility that ring tacticity accounts for some of the fine structure cannot be entirely discounted.The stereochemistry of 4 is discussed in relation to the four possible modes of addition of monomer to a carbene chain carrier during polymerization.