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Long Pan

Publications and source records attributed to Long Pan.

8 recordsLinked to original sources
arXiv2026

AlertGuardian: Intelligent Alert Life-Cycle Management for Large-scale Cloud Systems

Alerts are critical for detecting anomalies in large-scale cloud systems, ensuring reliability and user experience. However, current systems generate overwhelming volumes of alerts, degrading operational efficiency due to ineffective alert life-cycle management. This paper details the efforts of Company-X to optimize alert life-cycle management, addressing alert fatigue in cloud systems. We propose AlertGuardian, a framework collaborating large language models (LLMs) and lightweight graph models to optimize the alert life-cycle through three phases: Alert Denoise uses graph learning model with virtual noise to filter noise, Alert Summary employs Retrieval Augmented Generation (RAG) with LLMs to create actionable summary, and Alert Rule Refinement leverages multi-agent iterative feedbacks to improve alert rule quality. Evaluated on four real-world datasets from Company-X's services, AlertGuardian significantly mitigates alert fatigue (94.8\% alert reduction ratios) and accelerates fault diagnosis (90.5\% diagnosis accuracy). Moreover, AlertGuardian improves 1,174 alert rules, with 375 accepted by SREs (32% acceptance rate). Finally, we share success stories and lessons learned about alert life-cycle management after the deployment of AlertGuardian in Company-X.

cs.DC↗
arXiv2024

Gaseous Scissor-mediated Electrochemical Exfoliation of Halogenated MXenes and its Boosting in Wear-Resisting Tribovoltaic Devices

Two-dimensional transition metal carbides (MXenes), especially their few-layered nanosheets, have triggered burgeoning research attentions owing to their superiorities including extraordinary conductivity, accessible active surface, and adjustable processability. Molten salts etching route further achieves their controllable surface chemistry. However, the method encounters challenges in achieving few-layer structures due to more complex delamination behaviors. Herein, we present an efficient strategy to fabricate Cl- or Br-terminated MXene nanoflakes with few-layers, achieved by electrochemical intercalation of Li ions and concomitant solvent molecules in the electrolyte solution, with gaseous scissors (propylene molecules) to break up interlayer forces. By controlling cut-off voltages, the optimal protocol results in nanosheets with an ultrahigh yield (~93%) and preserved surface chemistry. The resultant MXenes dispersions were employed as lubricants to enhance tribovoltaic nanogenerators, where Ti3C2Br2 displayed superior electrical output. These findings facilitate the understanding of MXenes' intrinsic physical properties and enable the nanoengineering of advanced electronic devices.

physics.app-ph↗
arXiv2024

Single picture single photon single pixel 3D imaging through unknown thick scattering medium

Imaging through thick scattering media presents significant challenges, particularly for three-dimensional (3D) applications. This manuscript demonstrates a novel scheme for single-image-enabled 3D imaging through such media, treating the scattering medium as a lens. This approach captures a comprehensive image containing information about objects hidden at various depths. By leveraging depth from focus and the reduced thickness of the scattering medium for single-pixel imaging, the proposed method ensures robust 3D imaging capabilities. We develop both traditional metric-based and deep learning-based methods to extract depth information for each pixel, allowing us to explore the locations of both positive and negative objects, whether shallow or deep. Remarkably, this scheme enables the simultaneous 3D reconstruction of targets concealed within the scattering medium. Specifically, we successfully reconstructed targets buried at depths of 5 mm and 30 mm within a total medium thickness of 60 mm. Additionally, we can effectively distinguish targets at three different depths. Notably, this scheme requires no prior knowledge of the scattering medium, no invasive procedures, reference measurements, or calibration.

physics.optics↗
arXiv2023

Birational geometry of moduli space of del Pezzo pairs

In this paper, we investigate the geometry of the moduli space $P_d$ of degree $d$ smooth del Pezzo pairs, which consists of a smooth del Pezzo surface $X$ of degree $d$ and a smooth curve $C \sim -2K_X$. More precisely, we study the compactifications of $P_d$ from both Hodge-theoretic and geometric invariant theoretical (GIT) perspectives. We obtain the class numbers of the Baily-Borel compactification $P_d^\ast$ for $P_d$, which is an important step toward establishing the Hassett-Keel-Looijenga program for $P_d$. If $d=8$, $P_d$ has two connected components. For the component parametrizing del Pezzo pairs $(Bl_p \PP^2, C)$, we propose the Hassett-Keel-Looijenga models $\cF(s)=\proj R(\cF,\Delta(s) )$ via the section rings of certain $\bQ$-line bundles $\Delta(s)$ on the locally symmetric variety $\cF$. These models are expected to connect different birational models of the moduli space arising from K-moduli theory. By constructing an arithmetic stratification on $\cF$ and computing the pullback of $\Delta(s)$ on these strata, we give arithmetic predictions for the wall-crossing of $\cF(s)$ as $s\in [0,1]$ varies. This work parallels that of Laza-O'Grady \cite{LO19, LaO18}.

math.AG↗
arXiv2023

Unleashing the Potential of Li-Metal Batteries A Breakthrough Ultra-High Room-Temperature Ionic Conductivity Composite Solid-State Electrolyte

The solid-state electrolyte is critical for achieving next-generation high energy density and high-safety batteries. Solid polymer electrolytes (SPEs) possess great potential for commercial application owing to their compatibility with the existing manufacturing systems. However, unsatisfactory room-temperature ionic conductivity severely limits its application. Herein, an ultra-high room-temperature ionic conductivity composite solid-state electrolyte (CSE) is prepared by introducing an appropriate amount of SiO2 nanosphere to the PVDF-HFP matrix. By doing this, the polymer particles are divided and surrounded by SiO2. And the interface amount is maximized resulting in the high ionic conductivity of 1.35 mS cm-1 under room temperature. In addition, the CSE shows a wide electrochemical window of 4.95 V and a moderate Li+ transference number of 0.44. The CSE demonstrates good stability with Li anode, with Li symmetric cells that could cycle 1000 h at a current density of 0.2 mA cm-2. The full cell assembled with LiFePO4 (LFP) and Li metal displays a high reversible specific capacity of 157.8 mAh g-1 at 0.1C, and it could maintain 92.9% of initial capacity after 300 cycles at 3C. Moreover, the strategy is applied in solid-state sodium/potassium batteries and displays excellent performance.

cond-mat.mtrl-sci↗
arXiv2023

K moduli of log del Pezzo pairs

We establish the full explicit wall-crossing for K-moduli space $\overline{P}^K_c$ of degree $8$ del Pezzo pairs $(X,cC)$ where generically $X \cong \bbF_1$ and $C \sim -2K_X$. We also show K-moduli spaces $\overline{P}^K_c$ coincide with Hassett-Keel-Looijenga(HKL) models $\cF(s)$ of a $18$-dimensional locally symmetric spaces associated to the lattice $E_8\oplus U^2\oplus E_7\oplus A_1$.

math.AG↗
arXiv2022

Your Router is My Prober: Measuring IPv6 Networks via ICMP Rate Limiting Side Channels

Active Internet measurements face challenges when some measurements require many remote vantage points. In this paper, we propose a novel technique for measuring remote IPv6 networks via side channels in ICMP rate limiting, a required function for IPv6 nodes to limit the rate at which ICMP error messages are generated. This technique, iVantage, can to some extent use 1.1M remote routers distributed in 9.5k autonomous systems and 182 countries as our "vantage points". We apply iVantage to two different, but both challenging measurement tasks: 1) measuring the deployment of inbound source address validation (ISAV) and 2) measuring reachability between arbitrary Internet nodes. We accomplish these two tasks from only one local vantage point without controlling the targets or relying on other services within the target networks. Our large-scale ISAV measurements cover ~50% of all IPv6 autonomous systems and find ~79% of them are vulnerable to spoofing, which is the most large-scale measurement study of IPv6 ISAV to date. Our method for reachability measurements achieves over 80% precision and recall in our evaluation. Finally, we perform an Internet-wide measurement of the ICMP rate limiting implementations, present a detailed discussion on ICMP rate limiting, particularly the potential security and privacy risks in the mechanism of ICMP rate limiting, and provide possible mitigation measures. We make our code available to the community.

cs.NI↗