arXiv subjects

Liu Lin

Publications and source records attributed to Liu Lin.

15 recordsLinked to original sources

arXiv2026

GRAB: An LLM-Inspired Sequence-First Click-Through Rate Prediction Modeling Paradigm

Traditional Deep Learning Recommendation Models (DLRMs) face increasing bottlenecks in performance and efficiency, often struggling with generalization and long-sequence modeling. Inspired by the scaling success of Large Language Models (LLMs), we propose Generative Ranking for Ads at Baidu (GRAB), an end-to-end generative framework for Click-Through Rate (CTR) prediction. GRAB integrates a novel Causal Action-aware Multi-channel Attention (CamA) mechanism to effectively capture temporal dynamics and specific action signals within user behavior sequences. Full-scale online deployment demonstrates that GRAB significantly outperforms established DLRMs, delivering a 3.05% increase in revenue and a 3.49% rise in CTR. Furthermore, the model demonstrates desirable scaling behavior: its expressive power shows a monotonic and approximately linear improvement as longer interaction sequences are utilized.

cs.IR↗

arXiv2025

UniGlyph: Unified Segmentation-Conditioned Diffusion for Precise Visual Text Synthesis

Text-to-image generation has greatly advanced content creation, yet accurately rendering visual text remains a key challenge due to blurred glyphs, semantic drift, and limited style control. Existing methods often rely on pre-rendered glyph images as conditions, but these struggle to retain original font styles and color cues, necessitating complex multi-branch designs that increase model overhead and reduce flexibility. To address these issues, we propose a segmentation-guided framework that uses pixel-level visual text masks -- rich in glyph shape, color, and spatial detail -- as unified conditional inputs. Our method introduces two core components: (1) a fine-tuned bilingual segmentation model for precise text mask extraction, and (2) a streamlined diffusion model augmented with adaptive glyph conditioning and a region-specific loss to preserve textual fidelity in both content and style. Our approach achieves state-of-the-art performance on the AnyText benchmark, significantly surpassing prior methods in both Chinese and English settings. To enable more rigorous evaluation, we also introduce two new benchmarks: GlyphMM-benchmark for testing layout and glyph consistency in complex typesetting, and MiniText-benchmark for assessing generation quality in small-scale text regions. Experimental results show that our model outperforms existing methods by a large margin in both scenarios, particularly excelling at small text rendering and complex layout preservation, validating its strong generalization and deployment readiness.

cs.CV↗

arXiv2024

IC Mechanisms for Risk-Averse Advertisers in the Online Advertising System

The autobidding system generates huge revenue for advertising platforms, garnering substantial research attention. Existing studies in autobidding systems focus on designing Autobidding Incentive Compatible (AIC) mechanisms, where the mechanism is Incentive Compatible (IC) under ex ante expectations. However, upon deploying AIC mechanisms in advertising platforms, we observe a notable deviation between the actual auction outcomes and these expectations during runtime, particularly in the scene with few clicks (sparse-click). This discrepancy undermines truthful bidding among advertisers in AIC mechanisms, especially for risk-averse advertisers who are averse to outcomes that do not align with the expectations. To address this issue, we propose a mechanism, Decoupled First-Price Auction (DFP), that retains its IC property even during runtime. DFP dynamically adjusts the payment based on real-time user conversion outcomes, ensuring that advertisers' realized utilities closely approximate their expected utilities during runtime. To realize the payment mechanism of DFP, we propose a PPO-based RL algorithm, with a meticulously crafted reward function. This algorithm dynamically adjusts the payment to fit DFP mechanism. We conduct extensive experiments leveraging real-world data to validate our findings.

cs.GT↗

arXiv2017

T-bulge single photon quantum router with three level system

This paper considers the transmission characteristics of incidenting from an infinte coupled-resonator waveguide (CRW) or a semi-infinite CRW, respectively. The Nth cavity of a semi-infinite CRW intersecting with an infinite CRW and a cascade three level system(CTLS) form a T-bulge structure. Due to symmetry breaking boundary, the maximum of transfer rate would reach unity when light incidenting from the semi-infinite CRW, while reach 0.5 for infinite CRW case. The position of the intersection have effect on the location of the extreme point of the transmission coefficients changing with couple strength. 4D figures are used to illustrate the transmission characteristics, which is more visable.

quant-ph↗

arXiv2009

Habitable Zones for Earth-mass Planets in Multiple Planetary Systems

We perform numerical simulations to study the Habitable zones (HZs) and dynamical structure for Earth-mass planets in multiple planetary systems. For example, in the HD 69830 system, we extensively explore the planetary configuration of three Neptune-mass companions with one massive terrestrial planet residing in 0.07 AU $\leq a \leq$ 1.20 AU, to examine the asteroid structure in this system. We underline that there are stable zones of at least $10^5$ yr for low-mass terrestrial planets locating between 0.3 and 0.5 AU, and 0.8 and 1.2 AU with final eccentricities of $e < 0.20$. Moreover, we also find that the accumulation or depletion of the asteroid belt are also shaped by orbital resonances of the outer planets, for example, the asteroidal gaps at 2:1 and 3:2 mean motion resonances (MMRs) with Planet C, and 5:2 and 1:2 MMRs with Planet D. In a dynamical sense, the proper candidate regions for the existence of the potential terrestrial planets or HZs are 0.35 AU $< a < $ 0.50 AU, and 0.80 AU $< a < $ 1.00 AU for relatively low eccentricities, which makes sense to have the possible asteroidal structure in this system.

astro-ph.EP↗

arXiv2009

The Dynamical Architecture and Habitable Zones of the Quintuplet Planetary System 55 Cancri

We perform numerical simulations to study the secular orbital evolution and dynamical structure in the quintuplet planetary system 55 Cancri with the self-consistent orbital solutions by Fischer and coworkers (2008). In the simulations, we show that this system can be stable at least for $10^{8}$ yr. In addition, we extensively investigate the planetary configuration of four outer companions with one terrestrial planet in the wide region of 0.790 AU $\leq a \leq $ 5.900 AU to examine the existence of potential asteroid structure and Habitable Zones (HZs). We show that there are unstable regions for the orbits about 4:1, 3:1 and 5:2 mean motion resonances (MMRs) with the outermost planet in the system, and several stable orbits can remain at 3:2 and 1:1 MMRs, which is resemblance to the asteroidal belt in solar system. In a dynamical point, the proper candidate HZs for the existence of more potential terrestrial planets reside in the wide area between 1.0 AU and 2.3 AU for relatively low eccentricities.

astro-ph.EP↗

arXiv2008

Baroclinic Generation of Potential Vorticity in an Embedded Planet-Disk System

We use a multi-dimensional hydrodynamics code to study the gravitational interaction between an embedded planet and a protoplanetary disk with emphasis on the generation of vortensity (Potential Vorticity or PV) through a Baroclinic Instability. We show that the generation of PV is very common and effective in non-barotropic disks through the Baroclinic Instability, especially within the coorbital region. Our results also complement previous work that non-axisymmetric Rossby-Wave Instabilities (RWIs, Lovelace et al. 1999) are likely to develop at local minima of PV distribution that are generated by the interaction between a planet and an inviscid barotropic disk. The development of RWIs results in non-axisymmetric density blobs, which exert stronger torques onto the planet when they move to the vicinity of the planet. Hence, large amplitude oscillations are introduced to the time behavior of the total torque acted on the planet by the disk. In current simulations, RWIs do not change the overall picture of inward orbital migration but cause a non-monotonic behavior to the migration speed. As a side effect, RWIs also introduce interesting structures into the disk. These structures may help the formation of Earth-like planets in the Habitable Zone or Hot Earths interior to a close-in giant planet.

astro-ph↗

arXiv2006

On Secular Resonances of Small Bodies in the Planetary Systems

We investigate the secular resonances for massless small bodies and Earth-like planets in several planetary systems. We further compare the results with those of Solar System. For example, in the GJ 876 planetary system, we show that the secular resonances $ν_1$ and $ν_2$ (respectively, resulting from the inner and outer giant planets) can excite the eccentricities of the Earth-like planets with orbits 0.21 AU $\leq a <$ 0.50 AU and eject them out of the system in a short timescale. However, in a dynamical sense, the potential zones for the existence of Earth-like planets are in the area 0.50 AU $\leq a \leq$ 1.00 AU, and there exist all stable orbits last up to $10^5$ yr with low eccentricities. For other systems, e.g., 47 UMa, we also show that the Habitable Zones for Earth-like planets are related to both secular resonances and mean motion resonances in the systems.

astro-ph↗

arXiv2006

The Secular Evolution and Dynamical Architecture of the Neptunian Triplet Planetary System HD 69830

We perform numerical simulations to study the secular orbital evolution and dynamical structure in the HD 69830 system with the best-fit orbital solutions by Lovis and coworkers (2006). In the simulations, we show that the triplet Neptunian system can be stable at least for 2 Gyr and the stability would not be greatly influenced even if we vary the planetary masses. In addition, we employ the Laplace-Lagrange secular theory to investigate the long-term behaviors of the system, and the outcomes demonstrate that this theory can well describe the secular orbital evolution for all planets, where the secular periods and amplitudes in the eccentricities well agrees with those of the direct numerical integrations. We first reveal that the secular periods of the eccentricity $e_{1}$ and $e_{2}$ are identical about 8,300 yr. Moreover, we explore the planetary configuration of three Neptune-mass companions with one massive terrestrial planet in 0.07 AU $\leq a \leq 1.20$ AU, to examine the asteroid structure in this system. We underline that there are stable zones at least $10^{5}$ yr for low-mass terrestrial planets locating between 0.3 and 0.5 AU, and 0.8 and 1.2 AU with final low eccentricities. Still, we also find that the secular resonance $ν_{1}$ and $ν_{2}$ of two inner planets can excite the eccentricities of the terrestrial bodies, and the accumulation or depletion of the asteroid belt are also shaped by orbital resonances of the outer planets, i.e., 5:2 and 1:2 MMRs with Planet D... (abridged)

astro-ph↗

arXiv2005

The Stable Topology of the Planetary Systems of two 2:1 Resonant Companions:Application to HD 82943

We have numerically explored the stable planetary geometry for the multiple systems involved in a 2:1 mean motion resonance, and herein we mainly study the HD 82943 system by employing two sets of the orbital parameters (Mayor et al. 2004; Ji et al. 2004). In the simulations, we find that all stable orbits are related to the 2:1 resonance that can help to remain the semi-major axes for two companions almost unaltered over the secular evolution for $10^{8}$ yr. In addition, we also show that there exist three possible stable configurations:(1) Type I, only $θ_{1} \approx 0^{\circ}$, (2) Type II, $θ_{1}\approxθ_{2}\approxθ_{3}\approx 0^{\circ}$ (aligned case), and (3) Type III, $θ_{1}\approx 180^{\circ}$, $θ_{2}\approx0^{\circ}$, $θ_{3}\approx180^{\circ}$ (antialigned case), where two resonant arguments are $θ_{1} = λ_{1} - 2λ_{2} + \varpi_{1}$ and $θ_{2} = λ_{1} - 2λ_{2} + \varpi_{2}$, the relative apsidal longitudes $θ_{3} = \varpi_{1}-\varpi_{2}=Δ\varpi$. And we find that other 2:1 resonant systems (e.g., GJ 876) may possess one of three stable orbits in their realistic motions. Moreover, we also study the existence of the assumed terrestrial bodies at $\sim 1$ AU for HD 82943 and GJ 876 systems (see main texts).

astro-ph↗

arXiv2004

Could the 55 Cancri Planetary System Really Be in the 3:1 Mean Motion Resonance?

We integrate the orbital solutions of the planets orbiting 55 Cnc. In the simulations, we find that not only three resonant arguments $θ_{1}=λ_{1}-3λ_{2}+2\tildeω_{1}$, $θ_{2}=λ_{1}-3λ_{2}+2\tildeω_{2}$ and $θ_{3}=λ_{1}-3λ_{2}+(\tildeω_{1}+\tildeω_{2})$ librate respectively, but the relative apsidal longitudes $Δω$ also librates about $250^{\circ}$ for millions of years. The results imply the existence of the 3:1 resonance and the apsidal resonance for the studied system. We emphasize that the mean motion resonance and apsidal locking can act as two important mechanisms of stabilizing the system. In addition, we further investigate the secular dynamics of this system by comparing the numerical results with those given by Laplace-Lagrange secular theory.

astro-ph↗

arXiv2004

The Stable Planetary Geometry of the Exosystems in 2:1 Mean Motion Resonance

(Abridged) We have numerically explored the stable planetary geometry for the multiple systems involved in a 2:1 mean motion resonance, and herein we mainly concentrate on the study of the HD 82943 system by employing two sets of the orbital parameters (Mayor et al. 2004). We find that all stable orbits are related to the 2:1 commensurability for $10^{7}$ yr, and the apsidal phase-locking between two orbits can further enhance the stability for this system. For HD 82943, there exist three possible stable configurations:(1) Type I, only $θ_{1} \approx 0^{\circ}$,(2) Type II, $θ_{1}\approxθ_{2}\approxθ_{3}\approx 0^{\circ}$ (aligned case), and (3) Type III, $θ_{1}\approx 180^{\circ}$, $θ_{2}\approx0^{\circ}$, $θ_{3}\approx180^{\circ}$ (antialigned case), here the lowest eccentricity-type mean motion resonant arguments are $θ_{1} = λ_{1} - 2λ_{2} + \varpi_{1}$ and $θ_{2} = λ_{1} - 2λ_{2} + \varpi_{2}$, the relative apsidal longitudes $θ_{3} = \varpi_{1}-\varpi_{2}=Δ\varpi$. In addition, we also propose a semi-analytical model to study $e_{i}-Δ\varpi$ Hamiltonian contours. With the updated fit, we examine the dependence of the stability of this system on the orbital parameters. Moreover, we numerically show that the assumed terrestrial bodies cannot survive near the habitable zones for HD 82943 and low-mass planets can be dynamically habitable in the GJ 876 system at $\sim 1$ AU in the numerical surveys.

astro-ph↗

arXiv2003

The Apsidal Antialignment of the HD 82943 System

We perform numerical simulations to explore the dynamical evolution of the HD 82943 planetary system. By simulating diverse planetary configurations, we find two mechanisms of stabilizing the system: the 2:1 mean motion resonance between the two planets can act as the first mechanism for all stable orbits. The second mechanism is a dynamical antialignment of the apsidal lines of the orbiting planets, which implies that the difference of the periastron longitudes $θ_{3}$ librates about $180^{\circ}$ in the simulations. We also use a semi-analytical model to explain the numerical results for the system under study.

astro-ph↗

arXiv2002

The Stability Analysis of the HD 82943 and HD 37124 Planetary Systems

We carry out numerical simulations to explore the dynamical evolution of the HD 82943 and HD 37124 planetary systems,which both have two Jupiter-like planets. By simulating various planetary configurations in the neighborhood of the fitting orbits, we find three mechanisms to maintain the stability of these systems: For HD 82943,we find that the 2:1 mean motion resonance can act as the first mechanism for all the stable orbits. The second mechanism is the alignment of the periastron of the two planets of HD 82943 system. In the paper,we show one case is simultaneously maintained by the two mechanisms. Additionally,we also use the corresponding analytical models successfully to explain the different numerical results for the system. The third mechanism is the Kozai resonance which takes place in the mutual highly orbits of HD 37124. In the simulations,we discover that the argument of periastron $ω$ of the inner planet librates about $90^{\circ}$ or $270^{\circ}$ for the whole time span. The Kozai mechanism can explain the stable configuration of large eccentricity of the inner planet.

astro-ph↗

arXiv2002

The Dynamical Simulations of the Planets Orbiting GJ 876

We have performed simulations to investigate the dynamics of the M dwarf star GJ 876 in an attempt to reveal any stabilizing mechanism for sustaining the system.We simulated different coplanar and noncoplanar configurations of two-planet systems and other cases.From the simulations,we found that the 2 :1 mean-motion resonance between two planets can act as an effective mechanism for maintaining the stability of the system.This result is explained by a proposed analytical model.Using this model,we studied the region of motion of the inner planet by varying the parameters of the system,and we detected that the analytical results are well consistent with the numerical simulations.

astro-ph↗