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Single-Trim Highly Accurate Frequency Reference Techniques
No full textThis paper describes a CMOS frequency reference system that achieves quartz-crystal-oscillator-rivaling frequency accuracy and power consumption across a temperature range of 228°, with low degradation over lifetime. This system uses only a batch calibration and a sample-specific single-temperature production-time calibration. The reference frequency is generated by a tunable RC-based oscillator (RCO) at relatively low power. The RCO's significant process and temperature dependencies, and degradation over lifetime, are eliminated by periodically recalibrating it to a co-integrated inherently robust LC-oscillator (LCO). The resulting hybrid RC/LC CMOS frequency reference system combines the low-power properties of the RCO and the single-trim highly-accurate and low-ageing properties of an LCO. This paper reviews circuit and system aspects of this frequency reference system, complemented with measurement results and insights for key devices and for many effects that limit system accuracy over wide temperature ranges and over lifetime.</p
Biodiversity conservation & spatial patterns for climate change impact and adaptation
No full textAn Essential Climate Variable (ECV) is a physical, chemical or biological variable or a group of linked variables that critically contributes to the characterization of Earth’s climate. GCOS currently specifies 55 ECVs. ECV datasets provide the empirical evidence needed to understand and predict the evolution of climate, to guide mitigation and adaptation measures, to assess risks and enable attribution of climate events to be underlying causes, and to underpin climate services. They are required to support the work of the UNFCCC and the IPCC
First job or career change:What is the professional well-being of novice teachers in secondary education?
No full textBeginning teachers in secondary education experience pressure that can lead to dropout. This applies to both teachers with a previous career outside of education (career switchers) and those without (career starters). Educational regions are tasked with providing regionally coherent support services. To do so, they must have a clear understanding of their beginning teachers, including how their policy frameworks are implemented and perceived by the target group. Therefore, this study examines the professional well-being and experiences of beginning teachers within the policy context as a case study in the VOTA (United Education Twente Achterhoek) educational region, using document analysis and a questionnaire. The experiences of 117 career switchers and starters in this case study reveal clear similarities regarding their well-being, classroom behavior, and how they are supported, but also some differences, including regarding setting boundaries, the causes of work stress, and reasons for leaving. This study can provide teacher educators and policymakers within educational regions with insights into the professional well-being and behavior of beginning teachers during their professional development in the work environment
Experimental demonstration of boson sampling as a hardware accelerator for monte carlo integration
No full textWe present an experimental demonstration of boson sampling as a hardware accelerator for Monte Carlo integration. Our approach leverages importance sampling to factorize an integrand into a distribution that can be sampled using quantum hardware and a function that can be evaluated classically, enabling hybrid quantum-classical computation. We argue that for certain classes of integrals, this method offers a quantum advantage by efficiently sampling from probability distributions that are hard to simulate classically. We also identify structural criteria that must be satisfied to preserve computational hardness, notably the sensitivity of the classical post-processing function to high-order quantum correlations. To validate our protocol, we implement a proof-of-principle experiment on a programmable photonic platform to compute the first-order energy correction of a three-boson system in a harmonic trap under an Efimov-inspired three-body perturbation. The experimental results are consistent with theoretical predictions and numerical simulations, with deviations explained by photon distinguishability, discretization, and unitary imperfections. Additionally, we provide an error budget quantifying the impact of these same sources of noise. Our work establishes a concrete use case for near-term photonic quantum devices and highlights a viable path toward practical quantum advantage in scientific computing
Toward Approximate Computing for Deep Learning in Embedded Systems:A Systematic Literature Review
No full textThe evolution of Deep Learning (DL) algorithms, coupled with the availability of vast amounts of data, has enabled superior accuracy across multiple Artificial Intelligence (AI) tasks. However, such accuracy incurs substantial computational and energy costs, limiting deployment on resource-constrained embedded devices. Approximate Computing has emerged as a promising paradigm to mitigate this challenge by trading off tolerable accuracy loss for significant gains in energy, power, area, and performance. Leveraging the inherent error resilience of DL models, approximation techniques have been extensively explored at multiple layers of the DL computing stack, and several surveys also exist. However, to the best of our knowledge, no prior Systematic Literature Review (SLR) exists that is specifically focused on Approximate Computing for DL in Embedded Systems. This article presents SLR by selecting 51 studies published between January 2019 and May 2025. These studies are organized into four categories corresponding to layers of the DL computing stack, including cross-layer approximations. Furthermore, 12 approximation techniques, 11 benchmark datasets, 26 prominent DL architectures, and three embedded platforms for the energy-efficient DL deployment are summarized, along with the leading tools, frameworks, and optimization/evaluation metrics. Additionally, the academic and industry-wide global adoption has also been highlighted. This SLR reveals that Approximate Multipliers, CIFAR-10 and MNIST datasets, ResNet-50 and LeNet models, and ASIC-based 45 nm technology designs are most frequently targeted, whereas Synopsys DC, PyTorch, and Verilog emerged as the predominant tools and frameworks supporting approximations in DL. Finally, this SLR highlights the current challenges, research gaps, and introduces a conceptual cross-layer approximate DL framework to address them. The findings of this SLR offer a comprehensive reference for the researchers and practitioners to select suitable approximation techniques along with the underlying tools and hardware platforms, aligned with their application requirements
Weaving Stories of Connection:A Design Study on Developing Science Teachers' Storytelling Competencies for Ecological Citizenship
No full textThis qualitative design study is aimed at the development of a research-based module enhancing science teachers' storytelling competencies. The module's core focus is storytelling as a pedagogical tool for supporting students' morality development in relation to the more-than-human world. Also, this study aims to develop more universal design principles for integrating storytelling into secondary science education to foster ecological morality.Storytelling in science education has the potential to be a powerful pedagogical tool to support students to critically examine our disrupted relation with the more-than-human world, as well as to encourage them to reflect upon (alternative) hopeful forms of relations in it. Activities during the different phases of this study are interviews with/ training by (professional) storytellers; development of sample stories/materials to inspire science teachers; design of a storytelling module; set-up a professional learning community (PLC): teacher training, exchange experiences, mutual feedback during (follow-up) meetings. Data sources for this study include PLC teachers’ reflective diaries, kept during the implementation phase; interviews with both students and PLC teachers about their findings and experiences with storytelling.During the ESERA 2025 interactive poster presentation, we expect to share insights from the orientation and design phases, including initial design principles for storytelling modules and feedback from PLC teachers. Also, the poster will include some visual representations of key concepts central to the module, as well as QR codes that link to additional resources and references. Likely, we will bring some tangible objects, to be used as starting points for conversations.<br/
Improving Decision Quality in High-Tech System Design:An In-Depth Study Leveraging Industry Expertise
No full textTechnological advancement is driven by the development of high-tech systems. However, growing demands on technology lead to more system complexity and to complexity in developing organizations. Therefore, developing these high-tech systems requires systems engineering and high-quality decision-making to balance high performance requirements and a short time to market. In this work, we explore how to improve decision quality within the context of a partner company from the semiconductor industry that deals with these challenges daily. We use triangulation of literature, a survey of 93 systems engineers from the company, and case studies of twelve decisions at the same company. The results highlight three main aspects pertaining to decision quality, namely (1) focusing on the preparation of the decision, (2) gathering the right knowledge and information, and (3) prioritizing (pre-decision) stakeholder alignment. These results will be used to develop a support for the preparation of high-tech systems design decisions, focusing on what knowledge is required and where that knowledge comes from. We found that these are the most important aspects for improving decision quality in high-tech systems development with growing complexity
Deciphering the crosslink mechanism of dual cure EP(D)M and CTS rubber compounds for reduced oil swell
No full textRubber compounds containing blends of two or more polymers are common in various industrial applications, starting with the tire industry. Blends are most commonly comprising of materials that are compatible with each other. However, for blends that are comprising of polymeric materials with limited compatibility, understanding the limitation and ways to overcome it is paramount to ensuring rubber compounds homogeneity. In this study Ethylene Propylene (Diene) Polymer (EPDM) or Ethylene Propylene Polymer (EPM) and Cyclic Tetrasulfide (CTS) are combined with the goal of achieving a compound that has superior properties than EPDM or EPM. Thermodynamic studies are deployed to illustrate materials' compatibility. The role of CTS in the compound is discussed in detail, as it presents dual functions. This study represents a fundamental analysis of EP(D)M-CTS blends, starting with Thermodynamic studies and polymeric phase analysis by Scanning and Transmission Electron Microscopy (S(T)EM) hyphenated by Energy-Dispersive X-ray Spectroscopy (EDX) or Raman Spectroscopy. The resulting rubber compounds' mechanical properties are analyzed, including the Payne effect. The compound resistance against swelling when exposed to a standard hydrocarbon oil was tested on a side-by-side comparison with pure EPD and they show positive outcome. EPDM-CTS compounds have an increased resistance to swell in standard hydrocarbon oil. This feature is important in rubber articles such as for o-rings, gaskets, and other seal articles. The focus of this study is to elucidate the mechanism of crosslinking in rubber compounds comprising of EP(D)M and CTS. This fundamental understanding of the crosslinking chemical process signifies the building block for future EP(D)M-CTS compound development.</p