Runtime Analysis of Area-Efficient Uniform RO-PUF for Uniqueness and Reliability Balancing

The main issue of ring oscillator physical unclonable functions (RO-PUF) is the existence of unstable ROs in response to environmental variations. The RO pairs with close frequency differences tend to contribute bit flips, reducing the reliability. Research on improving reliability has been carried out over the years. However, it has led to other issues, such as decreasing the uniqueness and increasing the area utilized. Therefore, this paper proposes a uniform RO-PUF, requiring a smaller area than a conventional design, aiming to balance reliability and uniqueness. We analyzed RO runtimes to increase reliability. In general, our method (uniqueness = 47.48%, reliability = 99.16%) performs better than previously proposed methods for a similar platform (Altera), and the reliability is as good as the latest methods using the same IC technology (28 nm). Moreover, the reliability is higher than that of RO-PUF with challenge and response pair (CRP) enhancements. The evaluation was performed in longer runtimes, where the pulses produced by ROs exceeded the counter capacity. This work recommends choosing ranges of the runtime of RO for better performance. For the 11-stage ROs, the range should be 1.598–4.30 ms, or 6.12–8.61 ms, or 12.24–12.91 ms. Meanwhile, for the 20-stage, the range should be 2.717–8.37 ms, or 10.97–16.74 ms, or 21.93–25.10 ms.

A Machine-Learning Approach for Extracting Modulus of Compacted Unbound Aggregate Base and Subgrade Materials Using Intelligent Compaction Technology

This study presents a rigorous approach for the extraction of the modulus of soil and unbound aggregate base materials for quality management using intelligent compaction (IC) technology. The proposed approach makes use of machine-learning methods in tandem with IC technology and modulus-based spot testing as a local calibration process to estimate the mechanical properties of compacted geomaterials. A calibrated three-dimensional finite element (FE) model that simulates the proof-mapping process of compacted geomaterials was used to develop a comprehensive database of responses of a wide range of single and two-layered geosystems. The database was then used to develop different inverse solvers using artificial neural networks for the estimation of the modulus from the characteristics of the roller and information about the geomaterials. Several instrumented test sites were used for the evaluation and validation of the inverse solvers. The proposed approach was found promising for the extraction of the modulus of compacted geomaterials using IC. The accuracy of the inverse solvers is enhanced if a local calibration process is incorporated as part of a quality management program that includes the use of in situ measurements using modulus-based test devices and laboratory resilient modulus testing. Moreover, compaction uniformity plays a key role in the retrieval of the modulus of geomaterials with certainty. The proposed approach fuses artificial intelligence with mechanistic solutions to position IC as a technology that is well suited for the quality management of compacted materials.

Technologies for creating radiation-resistant VLSI

The technology of radiation-resistant CMOS VLSI is based on industrial IC technology. The design uses feedback circuits and guard rings to compensate for single effects of cosmic particles (SEE). In most critical cases, these influences in digital circuits lead to single faults (SEU), which temporarily disrupt the state of memory cells, to latching (SEL), and in the long term to a catastrophic change of state. Various space programs confirm great prospects for their use in future space structures. The article discusses the effects of using radiation-resistant CMOS technology, technology based on a silicon-on-sapphire structure, CMOS technology on an insulating substrate taking into account typical characteristics, SIMOX-SOI technology, which consists in separation by implantation of oxygen ions. In new designs of circuits, more advanced algorithms should be implemented for the future.

Achieving Injectivity Optimization and Zonal Rates Allocation through Multi-Zone Intelligent Completion Technology – A Field B Case Study from Offshore Malaysia

Properly distributing injected fluid to provide injection conformance and reservoir pressure support into the respective zones of interest in mature fields can be challenging. This challenge, with injection fluid distribution, is typically encountered in fields with high contrast in permeability, reservoir pressure, and injectivity indexes among individual zones. Deployment of intelligent completion (IC) technology to address this challenge has rapidly increased, especially in multi-zone water injector wells, due to its capabilities for real-time reservoir monitoring and control of the fluid injected into multiple zones without requiring well interventions. This paper presents a case study of successful installation of IC technology in two water injector wells in Field B offshore Sarawak. The main objective of the IC implementation is to provide an efficient water-injection method for pressure support to the nearby oil producers and counteract the gas expansion through water injection at the flank area. Water injection implementation using the IC approach can further develop the oil rims and improve oil recovery in the particular reservoir to extend the field's production life. The custom tailored inflow control valve (ICV) design is robust enough to provide control of desired zonal injection rates. Each well was installed with two sets of ICVs to control the injection rate for each dedicated zone as well as a real-time permanent downhole gauge (PDG) to monitor the pressure drop across the ICV for zonal rates allocation / analysis. Apart from conceptual and detailed engineering study of the applied IC technology, proper downhole equipment selection and integration with surface facilities are also crucial to ensure successful implementation of the IC system as a holistic solution to achieve the injection objective. Post well completion installation, a water injectivity test was performed in both the selective and commingle injection modes. During selective injection testing, different positions of the ICV were manipulated and the water injection rate was monitored. This testing approach was performed for each ICV in the well. Post selective injection testing, commingle testing was conducted at the base 9,000 bwpd and maximum injection target of 18,000 bwpd, in which the testing was successfully executed to achieve the maximum well target injection rate. This paper shall discuss the reservoir management strategy through deployment of the water injectors, conceptual well completion design, and multi-zone injectivity requirements. Details such as ICV design using pre-drill and post-drill information, final well completion strategy, pre-installation preparation, installation optimization, execution of the IC deployment, injectivity test procedure, and results are discussed as well.

A DC Circuit Model of Distributed Diodes on Active Substrate Boards for CAD Tools

In the past few years, a new type of circuit board, named here as active substrate board (ASB), was introduced over circuit applications of diodes. Unlike a traditional printed circuit board (PCB), an ASB has its substrate made of a semiconductor. The inability of the traditional integrated circuit (IC) technology to integrate wavelength dependent radio frequency (RF) components triggered the advent of ASBs. These boards draw desirable features from IC as well as PCB technologies. Unprecedented challenges came up in modeling the different devices fabricated on an ASB owing to their large sizes and the presence of wideband microwaves. So far, modeling the effect of large sizes and ambient microwaves on DC bias of diodes have not been considered in scientific literature. Furthermore, the state of the art numerical simulators are unable to imitate the behavior of such diodes observed over measurements. Here, a semi-analytical, circuit model of distributed diodes on ASB is presented that is fairly accurate in predicting the actual behavior of the diodes. The model also opines a novel phenomenon where microwaves affect the DC characteristics of diodes with added resistances.