Applying Trust for Operational States of ICT-Enabled Power Grid Services

Digitalization enables the automation required to operate modern cyber-physical energy systems (CPESs), leading to a shift from hierarchical to organic systems. However, digitalization increases the number of factors affecting the state of a CPES (e.g., software bugs and cyber threats). In addition to established factors like functional correctness, others like security become relevant but are yet to be integrated into an operational viewpoint, i.e. a holistic perspective on the system state. Trust in organic computing is an approach to gain a holistic view of the state of systems. It consists of several facets (e.g., functional correctness, security, and reliability), which can be used to assess the state of CPES. Therefore, a trust assessment on all levels can contribute to a coherent state assessment. This paper focuses on the trust in ICT-enabled grid services in a CPES. These are essential for operating the CPES, and their performance relies on various data aspects like availability, timeliness, and correctness. This paper proposes to assess the trust in involved components and data to estimate data correctness, which is crucial for grid services. The assessment is presented considering two exemplary grid services, namely state estimation and coordinated voltage control. Furthermore, the interpretation of different trust facets is also discussed.Comment: Preprint of the article under revision for the ACM Transactions on Autonomous and Adaptive Systems, Special Issue on 20 Years of Organic Computin

A Hands One Workshop on Computer Security Tools for Classroom Instruction

In the last ten years, the Internet has become an important component of the global economy and security has emerged as a important part of the Information Technology professions. It is clear that universities and colleges must start preparing professionals ready to take on these challenges in the workplace. NSA is actively encouraging universities and colleges to start new courses and programs in information assurance and recently, Pace University was awarded designation as a National Center of Academic Excellence in Information Assurance Education by NSA. This ½ day hands-on workshop will very briefly overview basic security issues (e.g. security policies and management, firewalls, host security, cryptography, application security, incident and disaster response, Social Engineering). Participants will learn a number of tools which are used in our introductory courses

Impact of ICT latency, data loss and data corruption on active distribution network control

The ongoing changes in modern power systems towards increasingly decentralized systems render the coordination of generation assets and the corresponding dependency on Information and Communication Technology highly relevant. This work demonstrates the impact of three types of ICT errors, namely delayed data, data loss and data corruption, on the control of distributed energy resources in an active distribution network. The settling time of the active power response at the interconnection point between the distribution and transmission system is investigated in the simulations. Additionally, two fallback strategies to mitigate the impact of data loss are proposed and evaluated with regard to their impact on the controller’s response. Finally, a generalized, aggregated service state description is proposed in order to capture the performance of the active distribution network service. It is meant to improve the interpretability of the results, which can be used to compare service designs and setups

Evaluation of the tear strength, compressive resistance, and surface hardness of three commercially available bite registration materials: an in vitro study

Background: For making a successful prosthesis, it is essential to achieve harmony between the maxillomandibular relationship. The precision and occlusal quality of the prosthesis partly depends on interocclusal bite registration material. Interocclusal bite registration material plays an important role in recording and transferring of existing patient’s occlusal records. The procedure used to record and transfer interocclusal relation should be performed with the utmost care and understanding to prevent clinical error. Aim: This study aimed to evaluate the tear strength, compressive resistance and surface hardness of three commercially available bite registration materials. Material and Methods: Three types of commercially available bite registration materials, Bis-acrylate (BA), Polyvinylsiloxane (PVS), and Polyether (PE), were made in Dumbbell and cylindrical shaped samples to evaluate the tear strength and compressive resistance, respectively and were analysed using the universal testing machine. The surface hardness was assessed using a microhardness tester. The obtained data were subjected to statistical analysis using SPSS 16.0 version (Chicago, Inc., USA). ANOVA/Kruskal-Wallis test was used to compare study parameters among the groups. Tukey’s posthoc test was used for inter-group comparisons. Results: Bis-Acrylate exhibited the greatest tear strength, followed by Polyvinylsiloxane and Polyether showed the least tear strength. More compressive resistance was observed in Polyether followed by Bis-Acrylate and lowest in Polyvinylsiloxane. A similar pattern was seen in the surface hardness among the three materials. Conclusion: Bis-acrylate showed greater tear strength and surface hardness, and it can be considered a better bite registration material

Modeling, Monitoring and Fault Diagnosis of Spacecraft Air Contaminants

Control of air contaminants is a crucial factor in the safety considerations of crewed space flight. Indoor air quality needs to be closely monitored during long range missions such as a Mars mission, and also on large complex space structures such as the International Space Station. This work mainly pertains to the detection and simulation of air contaminants in the space station, though much of the work is easily extended to buildings, and issues of ventilation systems. Here we propose a method with which to track the presence of contaminants using an accurate physical model, and also develop a robust procedure that would raise alarms when certain tolerance levels are exceeded. A part of this research concerns the modeling of air flow inside a spacecraft, and the consequent dispersal pattern of contaminants. Our objective is to also monitor the contaminants on-line, so we develop a state estimation procedure that makes use of the measurements from a sensor system and determines an optimal estimate of the contamination in the system as a function of time and space. The real-time optimal estimates in turn are used to detect faults in the system and also offer diagnoses as to their sources. This work is concerned with the monitoring of air contaminants aboard future generation spacecraft and seeks to satisfy NASA's requirements as outlined in their Strategic Plan document (Technology Development Requirements, 1996)

Modeling, Monitoring and Fault Diagnosis of Spacecraft Air Contaminants

Progress and results in the development of an integrated air quality modeling, monitoring, fault detection, and isolation system are presented. The focus was on development of distributed models of the air contaminants transport, the study of air quality monitoring techniques based on the model of transport process and on-line contaminant concentration measurements, and sensor placement. Different approaches to the modeling of spacecraft air contamination are discussed, and a three-dimensional distributed parameter air contaminant dispersion model applicable to both laminar and turbulent transport is proposed. A two-dimensional approximation of a full scale transport model is also proposed based on the spatial averaging of the three dimensional model over the least important space coordinate. A computer implementation of the transport model is considered and a detailed development of two- and three-dimensional models illustrated by contaminant transport simulation results is presented. The use of a well established Kalman filtering approach is suggested as a method for generating on-line contaminant concentration estimates based on both real time measurements and the model of contaminant transport process. It is shown that high computational requirements of the traditional Kalman filter can render difficult its real-time implementation for high-dimensional transport model and a novel implicit Kalman filtering algorithm is proposed which is shown to lead to an order of magnitude faster computer implementation in the case of air quality monitoring

Anticipatory anti-colonial writing in R.K. Narayan's Swami and Friends and Mulk Raj Anand's Untouchable

This article uses the term “anticipatory anti-colonial writing” to discuss the workings of time in R.K. Narayan’s Swami and Friends and Mulk Raj Anand’s Untouchable. Both these first novels were published in 1935 with the support of British literary personalities (Graham Greene and E.M. Forster respectively) and both feature young protagonists who, in contrasting ways, are engaged in Indian resistance to colonial rule. This study examines the difference between Narayan’s local, though ironical, resistance to the homogenizing temporal demands of empire and Anand’s awkwardly modernist, socially committed vision. I argue that a form of anticipation that explicitly looks forward to decolonization via new and transnational literary forms is a crucial feature of Untouchable that is not found in Swami and Friends, despite the latter’s anti-colonial elements. Untouchable was intended to be a “bridge between the Ganges and the Thames” and anticipates postcolonial negotiations of time that critique global inequalities and rely upon the multidirectional global connections forged by modernism

Two-photon polymerization of microneedles for transdermal drug delivery

Microneedles are small-scale devices that are finding use for transdermal delivery of protein-based pharmacologic agents and nucleic acid-based pharmacologic agents; however, microneedles prepared using conventional microelectronics-based technologies have several shortcomings, which have limited translation of these devices into widespread clinical use