Visible to the public Biblio

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2023-04-28
Nicholls, D., Robinson, A., Wells, J., Moshtaghpour, A., Bahri, M., Kirkland, A., Browning, N..  2022.  Compressive Scanning Transmission Electron Microscopy. ICASSP 2022 - 2022 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP). :1586–1590.
Scanning Transmission Electron Microscopy (STEM) offers high-resolution images that are used to quantify the nanoscale atomic structure and composition of materials and biological specimens. In many cases, however, the resolution is limited by the electron beam damage, since in traditional STEM, a focused electron beam scans every location of the sample in a raster fashion. In this paper, we propose a scanning method based on the theory of Compressive Sensing (CS) and subsampling the electron probe locations using a line hop sampling scheme that significantly reduces the electron beam damage. We experimentally validate the feasibility of the proposed method by acquiring real CS-STEM data, and recovering images using a Bayesian dictionary learning approach. We support the proposed method by applying a series of masks to fully-sampled STEM data to simulate the expectation of real CS-STEM. Finally, we perform the real data experimental series using a constrained-dose budget to limit the impact of electron dose upon the results, by ensuring that the total electron count remains constant for each image.
ISSN: 2379-190X
2023-02-02
Moon, S. J., Nagalingam, D., Ngow, Y. T., Quah, A. C. T..  2022.  Combining Enhanced Diagnostic-Driven Analysis Scheme and Static Near Infrared Photon Emission Microscopy for Effective Scan Failure Debug. 2022 IEEE International Symposium on the Physical and Failure Analysis of Integrated Circuits (IPFA). :1–6.
Software based scan diagnosis is the de facto method for debugging logic scan failures. Physical analysis success rate is high on dies diagnosed with maximum score, one symptom, one suspect and shorter net. This poses a limitation on maximum utilization of scan diagnosis data for PFA. There have been several attempts to combine dynamic fault isolation techniques with scan diagnosis results to enhance the utilization and success rate. However, it is not a feasible approach for foundry due to limited product design and test knowledge and hardware requirements such as probe card and tester. Suitable for a foundry, an enhanced diagnosis-driven analysis scheme was proposed in [1] that classifies the failures as frontend-of-line (FEOL) and backend-of-line (BEOL) improving the die selection process for PFA. In this paper, static NIR PEM and defect prediction approach are applied on dies that are already classified as FEOL and BEOL failures yet considered unsuitable for PFA due to low score, multiple symptoms, and suspects. Successful case studies are highlighted to showcase the effectiveness of using static NIR PEM as the next level screening process to further maximize the scan diagnosis data utilization.
2022-01-25
Malekzadeh, Milad, Papamichail, Ioannis, Papageorgiou, Markos.  2021.  Internal Boundary Control of Lane-free Automated Vehicle Traffic using a Linear Quadratic Integral Regulator. 2021 European Control Conference (ECC). :35—41.
Lane-free traffic has been recently proposed for connected automated vehicles (CAV). As incremental changes of the road width in lane-free traffic lead to corresponding incremental changes of the traffic flow capacity, the concept of internal boundary control can be used to optimize infrastructure utilization. Internal boundary control leads to flexible sharing of the total road width and capacity among the two traffic directions (of a highway or an arterial) in real-time, in response to the prevailing traffic conditions. A feedback-based Linear-Quadratic regulator with Integral action (LQI regulator) is appropriately developed in this paper to efficiently address this problem. Simulation investigations, involving a realistic highway stretch, demonstrate that the proposed simple LQI regulator is robust and very efficient.
2020-03-12
Shamsi, Kaveh, Pan, David Z., Jin, Yier.  2019.  On the Impossibility of Approximation-Resilient Circuit Locking. 2019 IEEE International Symposium on Hardware Oriented Security and Trust (HOST). :161–170.

Logic locking, and Integrated Circuit (IC) Camouflaging, are techniques that try to hide the design of an IC from a malicious foundry or end-user by introducing ambiguity into the netlist of the circuit. While over the past decade an array of such techniques have been proposed, their security has been constantly challenged by algorithmic attacks. This may in part be due to a lack of formally defined notions of security in the first place, and hence a lack of security guarantees based on long-standing hardness assumptions. In this paper we take a formal approach. We define the problem of circuit locking (cL) as transforming an original circuit to a locked one which is ``unintelligable'' without a secret key (this can model camouflaging and split-manufacturing in addition to logic locking). We define several notions of security for cL under different adversary models. Using long standing results from computational learning theory we show the impossibility of exponentially approximation-resilient locking in the presence of an oracle for large classes of Boolean circuits. We then show how exact-recovery-resiliency and a more relaxed notion of security that we coin ``best-possible'' approximation-resiliency can be provably guaranteed with polynomial overhead. Our theoretical analysis directly results in stronger attacks and defenses which we demonstrate through experimental results on benchmark circuits.

2020-02-26
Shi, Qihang, Vashistha, Nidish, Lu, Hangwei, Shen, Haoting, Tehranipoor, Bahar, Woodard, Damon L, Asadizanjani, Navid.  2019.  Golden Gates: A New Hybrid Approach for Rapid Hardware Trojan Detection Using Testing and Imaging. 2019 IEEE International Symposium on Hardware Oriented Security and Trust (HOST). :61–71.

Hardware Trojans are malicious modifications on integrated circuits (IC), which pose a grave threat to the security of modern military and commercial systems. Existing methods of detecting hardware Trojans are plagued by the inability of detecting all Trojans, reliance on golden chip that might not be available, high time cost, and low accuracy. In this paper, we present Golden Gates, a novel detection method designed to achieve a comparable level of accuracy to full reverse engineering, yet paying only a fraction of its cost in time. The proposed method inserts golden gate circuits (GGC) to achieve superlative accuracy in the classification of all existing gate footprints using rapid scanning electron microscopy (SEM) and backside ultra thinning. Possible attacks against GGC as well as malicious modifications on interconnect layers are discussed and addressed with secure built-in exhaustive test infrastructure. Evaluation with real SEM images demonstrate high classification accuracy and resistance to attacks of the proposed technique.

2017-03-08
Windisch, G., Kozlovszky, M..  2015.  Image sharpness metrics for digital microscopy. 2015 IEEE 13th International Symposium on Applied Machine Intelligence and Informatics (SAMI). :273–276.

Image sharpness measurements are important parts of many image processing applications. To measure image sharpness multiple algorithms have been proposed and measured in the past but they have been developed with having out-of-focus photographs in mind and they do not work so well with images taken using a digital microscope. In this article we show the difference between images taken with digital cameras, images taken with a digital microscope and artificially blurred images. The conventional sharpness measures are executed on all these categories to measure the difference and a standard image set taken with a digital microscope is proposed and described to serve as a common baseline for further sharpness measures in the field.