@Techmeme@techhub.social2026-03-04 14:41:04
MacBook Neo hands-on: a new product category for Apple, and it doesn't look budget with a vibrant display and aluminum body, but the keyboard is a bit flimsy (Devindra Hardawar/Engadget)
https://www.engadget.com/computing/laptops
@arXiv_csDS_bot@mastoxiv.page2026-02-03 07:35:01
End Cover for Initial Value Problem: Complete Validated Algorithms with Complexity Analysis
Bingwei Zhang, Chee Yap
https://arxiv.org/abs/2602.00162 https://arxiv.org/pdf/2602.00162 https://arxiv.org/html/2602.00162
arXiv:2602.00162v1 Announce Type: new
Abstract: We consider the first-order autonomous ordinary differential equation \[ \mathbf{x}' = \mathbf{f}(\mathbf{x}), \] where $\mathbf{f} : \mathbb{R}^n \to \mathbb{R}^n$ is locally Lipschitz. For a box $B_0 \subseteq \mathbb{R}^n$ and $h > 0$, we denote by $\mathrm{IVP}_{\mathbf{f}}(B_0,h)$ the set of solutions $\mathbf{x} : [0,h] \to \mathbb{R}^n$ satisfying \[ \mathbf{x}'(t) = \mathbf{f}(\mathbf{x}(t)), \qquad \mathbf{x}(0) \in B_0 . \]
We present a complete validated algorithm for the following \emph{End Cover Problem}: given $(\mathbf{f}, B_0, \varepsilon, h)$, compute a finite set $\mathcal{C}$ of boxes such that \[ \mathrm{End}_{\mathbf{f}}(B_0,h) \;\subseteq\; \bigcup_{B \in \mathcal{C}} B \;\subseteq\; \mathrm{End}_{\mathbf{f}}(B_0,h) \oplus [-\varepsilon,\varepsilon]^n , \] where \[ \mathrm{End}_{\mathbf{f}}(B_0,h) = \left\{ \mathbf{x}(h) : \mathbf{x} \in \mathrm{IVP}_{\mathbf{f}}(B_0,h) \right\}. \]
Moreover, we provide a complexity analysis of our algorithm and introduce a novel technique for computing the end cover $\mathcal{C}$ based on covering the boundary of $\mathrm{End}_{\mathbf{f}}(B_0,h)$. Finally, we present experimental results demonstrating the practicality of our approach.
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@arXiv_physicsfludyn_bot@mastoxiv.page2026-02-27 08:29:00
On the spatial structure and intermittency of soot in a lab-scale gas turbine combustor: Insights from large-eddy simulations
Leonardo Pachano, Daniel Mira, Abhijit Kalbhor, Jeroen van Oijen
https://arxiv.org/abs/2602.23155 https://arxiv.org/pdf/2602.23155 https://arxiv.org/html/2602.23155
arXiv:2602.23155v1 Announce Type: new
Abstract: This work presents a numerical investigation of soot formation in the Cambridge lab-scale gas turbine combustor. Large-eddy simulations (LES) of a swirl-stabilized ethylene flame are performed using the flamelet generated manifold method coupled with a discrete sectional model to account for soot formation, growth, and oxidation. The study aims to elucidate the mechanism governing the spatial structure and intermittency of soot, supported by comparisons with experimental data. The predicted soot distribution agrees well with measurements, with peak concentrations near the bluff body. Flow recirculation is identified as the key mechanism driving soot accumulation in fuel-rich regions, where surface reactions dominate soot mass growth. Soot intermittency arises from fluctuations in the flow field driven by interactions between the flame front and the recirculation vortex. Two soot modeling approaches are evaluated, differing in their treatment of soot model quantities: the first approach employs on-the-fly computation of source terms (FGM-C), while the second uses fully pre-tabulated source terms (FGM-T). Their predictive performance and computational cost are compared in the context of unsteady, sooting flames in swirl-stabilized combustors.
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@floheinstein@chaos.social2026-01-27 06:44:19
@johnleonard@mastodon.social2026-01-12 14:46:06
The US, following a directive from President Trump, is withdrawing from several key international cybersecurity and hybrid threat organisations, citing concerns over mismanagement and conflicts with national sovereignty. Experts are worried about the impact on global cybersecurity.
https://www.
@paulbusch@mstdn.ca2026-03-04 16:26:55
I mentioned previously that my son-in-law's sister and her husband are working on the new Cadillac #F1 team that will compete for the first time in 2026. The couple are both engineers who met over a decade ago while working for a racing team in Europe. That experience was why they were recruited and became one of a handful of rare Canadians working on the project team.
I'm not really a #Formula1 race fan but I am following this team because of the connection. They were recently at the auto show in Toronto where the race car was displayed. They shared a photo of them pointing to their names on the chassis, along with the names of the entire team. Track testing is now underway and it will be interesting to see how they stack up against the legendary manufacturers in this sport.
https://youtu.be/d7BDA7JGamk
@mapto@qoto.org2025-12-19 05:45:33
The consequences of the 996 working hour system:
"On the Chinese internet, the country’s current predicament – slowing economic growth, a falling birthrate, a meagre social safety net, increasing isolation on the world stage – is often expressed through buzzwords. There is tangping, or “lying flat”, a term used to describe the young generation of Chinese who are choosing to chill out rather than hustle in China’s high-pressure economy. There is runxue, or “run philosophy”, which re…
@blakes7bot@mas.torpidity.net2026-01-19 10:23:45
Series C, Episode 04 - Dawn of the Gods
AVON: We will do nothing to counter the force acting upon the Liberator. We then plot the Liberator's course on the main battle computer flight predictor to see exactly how she is behaving. Once we understand how the force is operating we may be some way toward defeating it.
TARRANT: Strange. The Liberator's following a curve. Traction beams produce straight-line motion. Zen, I want a prediction of the Liberator's course based …
@arXiv_physicsfludyn_bot@mastoxiv.page2026-02-26 09:23:30
A minimal wake-vortex model explains formation flight of flapping birds
Olivia Pomerenk, Kenneth S. Breuer
https://arxiv.org/abs/2602.22043 https://arxiv.org/pdf/2602.22043 https://arxiv.org/html/2602.22043
arXiv:2602.22043v1 Announce Type: new
Abstract: Collective patterns of motion emerge across biological taxa: insects swarm, fish school, and birds flock. In particular, large migratory birds form strikingly ordered V-shaped formations, which experiments and direct numerical simulations have demonstrated provide substantial energetic benefits during long-distance flight. However, the precise aerodynamic and morphological mechanisms underlying these benefits remain unclear. In this work, we develop a reduced-order model of the wake-vortex interactions between two flapping birds flying in tandem. The model retains essential unsteady flapping dynamics while remaining computationally tractable. By optimizing over a six-dimensional state space, which comprises the follower's three-dimensional relative position and three independent flapping parameters, we identify the energetically optimal leader-follower configuration of northern bald ibises. The predicted optimum agrees quantitatively with live-bird measurements. Because of its simplicity, the model allows for direct interrogation of the physical mechanisms responsible for this optimum. In particular, it isolates precisely how the follower's wing kinematics interact with the leader's wake to enhance aerodynamic efficiency. The model predicts an 11% reduction in total mechanical power for a follower in formation flight -- consistent with experimental estimates -- and shows that this saving arises from reductions in both induced and profile power, dominated by decreased profile power enabled primarily through reduced flapping amplitude and, secondarily, reduced upstroke flexion. These results provide a mechanistic explanation for the structure of V-formations and offer new insight into the aerodynamic principles governing collective flight.
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@arXiv_csOS_bot@mastoxiv.page2026-02-10 09:40:07
Equilibria: Fair Multi-Tenant CXL Memory Tiering At Scale
Kaiyang Zhao, Neha Gholkar, Hasan Maruf, Abhishek Dhanotia, Johannes Weiner, Gregory Price, Ning Sun, Bhavya Dwivedi, Stuart Clark, Dimitrios Skarlatos
https://arxiv.org/abs/2602.08800 https://arxiv.org/pdf/2602.08800 https://arxiv.org/html/2602.08800
arXiv:2602.08800v1 Announce Type: new
Abstract: Memory dominates datacenter system cost and power. Memory expansion via Compute Express Link (CXL) is an effective way to provide additional memory at lower cost and power, but its effective use requires software-level tiering for hyperscaler workloads. Existing tiering solutions, including current Linux support, face fundamental limitations in production deployments. First, they lack multi-tenancy support, failing to handle stacked homogeneous or heterogeneous workloads. Second, limited control-plane flexibility leads to fairness violations and performance variability. Finally, insufficient observability prevents operators from diagnosing performance pathologies at scale.
We present Equilibria, an OS framework enabling fair, multi-tenant CXL tiering at datacenter scale. Equilibria provides per-container controls for memory fair-share allocation and fine-grained observability of tiered-memory usage and operations. It further enforces flexible, user-specified fairness policies through regulated promotion and demotion, and mitigates noisy-neighbor interference by suppressing thrashing.
Evaluated in a large hyperscaler fleet using production workloads and benchmarks, Equilibria helps workloads meet service level objectives (SLOs) while avoiding performance interference. It improves performance over the state-of-the-art Linux solution, TPP, by up to 52% for production workloads and 1.7x for benchmarks. All Equilibria patches have been released to the Linux community.
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