Physics-Informed Machine Learning for Data Anomaly Detection, Classification, Localization, and Mitigation: A Review, Challenges, and Path Forward

Advancements in digital automation for smart grids have led to the installation of measurement devices like phasor measurement units (PMUs), micro-PMUs ($\mu$-PMUs), and smart meters. However, a large amount of data collected by these devices brings several challenges as control room operators need to use this data with models to make confident decisions for reliable and resilient operation of the cyber-power systems. Machine-learning (ML) based tools can provide a reliable interpretation of the deluge of data obtained from the field. For the decision-makers to ensure reliable network operation under all operating conditions, these tools need to identify solutions that are feasible and satisfy the system constraints, while being efficient, trustworthy, and interpretable. This resulted in the increasing popularity of physics-informed machine learning (PIML) approaches, as these methods overcome challenges that model-based or data-driven ML methods face in silos. This work aims at the following: a) review existing strategies and techniques for incorporating underlying physical principles of the power grid into different types of ML approaches (supervised/semi-supervised learning, unsupervised learning, and reinforcement learning (RL)); b) explore the existing works on PIML methods for anomaly detection, classification, localization, and mitigation in power transmission and distribution systems, c) discuss improvements in existing methods through consideration of potential challenges while also addressing the limitations to make them suitable for real-world applications

Unexplored photoluminescence from bulk and mechanically exfoliated few layers of Bi2Te3

We report the exotic photoluminescence (PL) behaviour of 3D topological insulator Bi2Te3 single crystals grown by customized self-flux method and mechanically exfoliated few layers (18 plus minus 2 nm)/thin flakes obtained by standard scotch tape method from as grown Bi2Te3 crystals.The experimental PL studies on bulk single crystal and mechanically exfoliated few layers of Bi2Te3 evidenced a broad red emission in the visible region. These findings are in good agreement with our theoretical results obtained using the ab initio density functional theory framework.Comment: Main MS (17 Pages text including 4 Figs): Suppl. info. (4 pages); Accepted Scientific Report

Demand-Side Threats to Power Grid Operations from IoT-Enabled Edge

The growing adoption of Internet-of-Things (IoT)-enabled energy smart appliances (ESAs) at the consumer end, such as smart heat pumps, electric vehicle chargers, etc., is seen as key to enabling demand-side response (DSR) services. However, these smart appliances are often poorly engineered from a security point of view and present a new threat to power grid operations. They may become convenient entry points for malicious parties to gain access to the system and disrupt important grid operations by abruptly changing the demand. Unlike utility-side and SCADA assets, ESAs are not monitored continuously due to their large numbers and the lack of extensive monitoring infrastructure at consumer sites. This article presents an in-depth analysis of the demand side threats to power grid operations including (i) an overview of the vulnerabilities in ESAs and the wider risk from the DSR ecosystem and (ii) key factors influencing the attack impact on power grid operations. Finally, it presents measures to improve the cyber-physical resilience of power grids, putting them in the context of ongoing efforts from the industry and regulatory bodies worldwide

Impact of Zn substitution on phase formation and superconductivity of Bi1.6Pb0.4 Sr2Ca2Cu3-xZnxO10 with x = 0.0, 0.015, 0.03, 0.06, 0.09 and 0.12

Samples of series Bi1.6Pb0.4Sr2Ca2Cu3-xZnxO10 with x = 0.0, 0.015, 0.03, 0.06, 0.09 and 0.12 are synthesized by solid-state reaction route. All the samples crystallize in tetragonal structure with majority (> 90%) of Bi-2223 (Bi2Sr2Ca2Cu3O10) phase (c-lattice parameter ~ 36 A0). The proportion of Bi-2223 phase decreases slightly with an increase in x. The lattice parameters a and c of main phase (Bi-2223) do not change significantly with increasing x. Superconducting critical transition temperature (Tc) decreases with x as evidenced by both resistivity [(T)] and AC magnetic susceptibility [(T)] measurements. Interestingly the decrement of Tc is not monotonic and the same saturates at around 96 K for x > 0.06. In fact Tc decreases fast (~10K/at%) for x = 0.015 and 0.03 samples and later nearly saturates for higher x values. Present results of Zn doping in Bi-2223 system are compared with Zn doped other HTSC (High temperature superconducting) systems, namely the RE-123 (REBa2Cu3O7) and La-214 ((La,Sr)2CuO4).Comment: 12, pages of text and Figs. TO APPEAR IN Mod. Phys. Lett. B (2005)

Evidence-based national vaccine policy

India has over a century old tradition of development and production of vaccines. The Government rightly adopted self-sufficiency in vaccine production and self-reliance in vaccine technology as its policy objectives in 1986. However, in the absence of a full-fledged vaccine policy, there have been concerns related to demand and supply, manufacture vs. import, role of public and private sectors, choice of vaccines, new and combination vaccines, universal vs. selective vaccination, routine immunization vs. special drives, cost-benefit aspects, regulatory issues, logistics etc. The need for a comprehensive and evidence based vaccine policy that enables informed decisions on all these aspects from the public health point of view brought together doctors, scientists, policy analysts, lawyers and civil society representatives to formulate this policy paper for the consideration of the Government. This paper evolved out of the first ever ICMR-NISTADS national brainstorming workshop on vaccine policy held during 4-5 June, 2009 in New Delhi, and subsequent discussions over email for several weeks, before being adopted unanimously in the present form