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Publicações

2025

Femtosecond written waveguides for evanescent excitation of resonant optical sensing devices

Autores
Amorim, VA; Maia, JM; Frigenti, G; Baldini, F; Berneschi, S; Farnesi, D; Jorge, PAS; Conti, GN; dos Santos, PSS; Marque, PVS;

Publicação
OPTICAL COMPONENTS AND MATERIALS XXII

Abstract
Optical resonant structures, such as circular disks and optical microbubble resonators (OMBRs), are crucial for highresolution chemical and biochemical sensing. Both can be integrated into microfluidic systems: resonant disks can be fabricated within microfluidic channels, while OMBRs use thin silica capillary walls to confine fluid samples in a hollowcore cavity. Optical modes are typically excited using tapered optical fibers, which offer efficiency but lack robustness for functional devices. This work presents two femtosecond laser-written waveguide designs for exciting whispering gallery modes (WGMs) in these resonant structures. For resonant disks, suspended waveguides are fabricated tangentially between the microfluidic channel walls. For OMBRs, integrated waveguides are written on fused silica substrates to excite resonant modes. Both configurations provide stable and robust optical sensing solutions. The OMBR platform achieved a sensitivity of 45 nm/RIU with a resolution of 4.4x10(-5) RIU, while monolithically integrated disks reached 80 nm/RIU with a resolution of 7.0x10(-4) RIU. In both cases, the Q-factor exceeded 10(4) across the measurement range. These results confirm that femtosecond laser-written waveguides can efficiently excite resonant modes, offering promising platforms for chemical and biochemical sensing applications.

2025

Co-optimization of Demand Response Aggregators and distribution system operator for resilient operation using machine learning based wind generation forecasting: A bilevel approach

Autores
Aghdam, FH; Zavodovski, A; Adetunji, A; Rasti, M; Pongracz, E; Javadi, MS; Catalao, JPS;

Publicação
INTERNATIONAL JOURNAL OF ELECTRICAL POWER & ENERGY SYSTEMS

Abstract
The increasing occurrence of extreme weather events has severely compromised the resilience of power distribution systems, resulting in widespread outages and substantial economic losses. This paper proposes a novel solution to enhance the resilience of distribution networks without the need for significant infrastructure upgrades. We introduce a bilevel optimization framework that integrates Demand Response Programs (DRPs) to strategically manage electricity consumption and mitigate the impact of system disruptions. The approach fosters collaboration between Distribution System Operators (DSOs) and Demand Response Aggregators (DRAs), optimizing both operational resilience and economic efficiency. To solve the bilevel problem, we employ a Mathematical Program with Equilibrium Constraints (MPEC), transforming the bilevel model into a single- level problem by utilizing the Karush-Kuhn-Tucker (KKT) conditions. This method is applicable when the lower-level problem is convex with linear constraints. The model also incorporates Long Short-Term Memory (LSTM) neural networks for wind generation forecasting, enhancing decision-making precision. Furthermore, we conduct multiple case studies under varying severities of incidents to evaluate the method's effectiveness. Simulations performed on the IEEE 33-bus test system using GAMS and Python validate that the proposed method not only improves system resilience but also encourages active consumer participation, making it a robust solution for modern smart grid applications. The simulation results show that by performing DRP to handle the contingencies in a high-impact incident, the resilience of the system can be improved by 5.3%.

2025

Optimizing job shop scheduling with speed-adjustable machines and peak power constraints: A mathematical model and heuristic solutions

Autores
Homayouni, SM; Fontes, DBMM;

Publicação
INTERNATIONAL TRANSACTIONS IN OPERATIONAL RESEARCH

Abstract
This paper addresses a job shop scheduling problem with peak power constraints, in which jobs can be processed once or multiple times on either all or a subset of the machines. The latter characteristic provides additional flexibility, nowadays present in many manufacturing systems. The problem is complicated by the need to determine both the operation sequence and starting time as well as the speed at which machines process each operation. Due to the adherence to renewable energy production and its intermittent nature, manufacturing companies need to adopt power-flexible production schedules. The proposed power control strategies, that is, adjusting processing speed and timing to reduce peak power requirements may impact production time (makespan) and energy consumption. Therefore, we propose a bi-objective approach that minimizes both objectives. A linear programming model is developed to provide a formal statement of the problem, which is solved to optimality for small-sized instances. We also proposed a multi-objective biased random key genetic algorithm framework that evolves several populations in parallel. Computational experiments provide decision and policymakers with insights into the implications of imposing or negotiating power consumption limits. Finally, the several trade-off solutions obtained show that as the power limit is lowered, the makespan increases at an increasing rate and a similar trend is observed in energy consumption but only for very small makespan values. Furthermore, peak power demand reductions of about 25% have a limited impact on the minimum makespan value (4-6% increase), while at the same time allowing for a small reduction in energy consumption.

2025

H&E to IHC virtual staining methods in breast cancer: an overview and benchmarking

Autores
Klöckner, P; Teixeira, J; Montezuma, D; Fraga, J; Horlings, HM; Cardoso, JS; Oliveira, SP;

Publicação
NPJ DIGITAL MEDICINE

Abstract
Immunohistochemistry (IHC) is crucial for the clinical categorisation of breast cancer cases. Deep generative models may offer a cost-effective alternative by virtually generating IHC images from hematoxylin and eosin samples. This review explores the state-of-the-art in virtual staining for breast cancer biomarkers (HER2, PgR, ER and Ki-67) and benchmarks several models on public datasets. It serves as a resource for researchers and clinicians interested in applying or developing virtual staining techniques.

2025

Beyond the Click: The Evolution of Digital Marketing and Its Ethical Dilemmas

Autores
Melo, D; Castro, B; Spínola, L; Brandao, L; Au-Yong-Oliveira, M;

Publicação
MARKETING AND SMART TECHNOLOGIES, ICMARKTECH 2024, VOL 1

Abstract
Digital marketing has become an integral part of the modern business landscape, revolutionizing the way companies promote their products and interact with their customers. In this essay, we aim to demonstrate how it can be related to an increased tendency for mental health problems and other societal complications, as well as developing insights into its evolution using the latest breakthroughs in technology. This study will provide an overview of the impacts of digital marketing on companies, and in society, resorting to classical literature, as well as recent studies and articles conducted on the matter. An online survey was developed to support our research, reaching 112 Portuguese participants. The scientific methodology used was the Chi-Square test, with a confidence margin of 95% targeting two focus groups, one with their ages comprised within 16-25 years old and the other from 35 to 50 years old. We perceived that there would be behavioral differences between people who were born in the digital marketing age and those who had to adapt to it. We also provided some possible solutions to the problems raised by digital marketing and explained how these issues could be exacerbated with the renaissance technology is facing recently.

2025

CCS25 - Artifact for "Jazzline: Composable CryptoLine functional correctness proofs for Jasmin programs"

Autores
Almeida, JB; Barbosa, M; Barthe, G; Blatter, L; Duarte, JD; Marinho Alves, GXD; Grégoire, B; Oliveira, T; Quaresma, M; Strub, PY; Tsai, MH; Wang, BY; Yang, BY;

Publicação
Ccs 2025 Proceedings of the 2025 ACM Sigsac Conference on Computer and Communications Security

Abstract
Jasmin is a programming language for high-speed and high-assurance cryptography. Correctness proofs of Jasmin programs are typically carried out deductively in EasyCrypt. This allows generality, modularity and composable reasoning, but does not scale well for low-level architecture-specific routines. CryptoLine offers a semi-automatic approach to formally verify algebraically-rich low-level cryptographic routines. CryptoLine proofs are self-contained: they are not integrated into higher-level formal verification developments. This paper shows how to soundly use CryptoLine to discharge subgoals in functional correctness proofs for complex Jasmin programs. We extend Jasmin with annotations and provide an automatic translation into a CryptoLine model, where most complex transformations are certified. We also formalize and implement the automatic extraction of the semantics of a CryptoLine proof to EasyCrypt. Our motivating use-case is the X-Wing hybrid KEM, for which we present the first formally verified implementation.

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