المؤلفون: Yoshida, Fumi, Yanagisawa, Toshifumi, Ito, Takashi, Kurosaki, Hirohisa, Yoshikawa, Makoto, Kamiya, Kohki, Jiang, Ji-an, Stern, Alan, Fraser, Wesley C., Benecchi, Susan D., Verbiscer, Anne J.

مصطلحات موضوعية: Astrophysics - Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics

الوصف: Observation datasets acquired by the Hyper Suprime-Cam (HSC) on the Subaru Telescope for NASA's New Horizons mission target search were analyzed through a method devised by JAXA. The method makes use of Field Programmable Gate arrays and was originally used to detect fast-moving objects such as space debris or near-Earth asteroids. Here we present an application of the method to detect slow-moving Kuiper Belt Objects (KBOs) in the New Horizons target search observations. A cadence that takes continuous images of one HSC field of view for half a night fits the method well. The observations for the New Horizons Kuiper Belt Extended Mission (NH/KEM) using HSC began in May 2020, and are ongoing. Here we show our result of the analysis of the dataset acquired from May 2020 through June 2021 that have already passed the proprietary period and are open to the public. We detected 84 KBO candidates in the June 2020 and June 2021 datasets, when the observation field was close to opposition.
Comment: 21 pages, 9 figures, 5 tables, accepted for publication on Publications of the Astronomical Society of Japan

الوصول الحر: http://arxiv.org/abs/2407.05673Test

المؤلفون: Lin, Zheyu, Jiang, Ning, Wang, Tinggui, Kong, Xu, Li, Dongyue, He, Han, Wang, Yibo, Zhu, Jiazheng, Li, Wentao, Jiang, Ji-an, Singh, Avinash, Teja, Rishabh Singh, Sahu, D. K., Jin, Chichuan, Maeda, Keiichi, Huang, Shifeng

مصطلحات موضوعية: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies

الوصف: The unluckiest star orbits a supermassive black hole elliptically. Every time it reaches the pericenter, it shallowly enters the tidal radius and gets partially tidal disrupted, producing a series of flares. Confirmation of a repeated partial tidal disruption event (pTDE) requires not only evidence to rule out other types of transients, but also proof that only one star is involved, as TDEs from multiple stars can also produce similar flares. In this letter, we report the discovery of a repeated pTDE, AT 2022dbl. In a quiescent galaxy at z=0.0284, two separate optical/UV flares have been observed in 2022 and 2024, with no bright X-ray, radio or mid-infrared counterparts. Compared to the first flare, the second flare has a similar blackbody temperature of ~26,000 K, slightly lower peak luminosity, and slower rise and fall phases. Compared to the ZTF TDEs, their blackbody parameters, bolometric energies and light curve shapes are all similar. The spectra taken during the second flare show a steeper continuum than the late-time spectra of the previous flare, consistent with a newly risen flare. More importantly, the possibility of two independent TDEs can be largely ruled out because the optical spectra taken around the peak of the two flares exhibit highly similar broad Balmer, N III and possible He II emission lines, especially the extreme ~4100{\AA} emission lines. This represents the first robust spectroscopic evidence for a repeated pTDE, which can soon be verified by observing the third flare, given its short orbital period.
Comment: 15 pages, 8 figures, submitted to ApJ Letters on 2024 Apr 27

الوصول الحر: http://arxiv.org/abs/2405.10895Test

المؤلفون: Yang, Xiaohan, Chu, Ji, Guo, Zechen, Huang, Wenhui, Liang, Yongqi, Liu, Jiawei, Qiu, Jiawei, Sun, Xuandong, Tao, Ziyu, Zhang, Jiawei, Zhang, Jiajian, Zhang, Libo, Zhou, Yuxuan, Guo, Weijie, Hu, Ling, Jiang, Ji, Liu, Yang, Linpeng, Xiayu, Chen, Tingyong, Chen, Yuanzhen, Niu, Jingjing, Liu, Song, Zhong, Youpeng, Yu, Dapeng

مصطلحات موضوعية: Quantum Physics

الوصف: Superconducting qubits are a promising platform for building fault-tolerant quantum computers, with recent achievement showing the suppression of logical error with increasing code size. However, leakage into non-computational states, a common issue in practical quantum systems including superconducting circuits, introduces correlated errors that undermine QEC scalability. Here, we propose and demonstrate a leakage reduction scheme utilizing tunable couplers, a widely adopted ingredient in large-scale superconducting quantum processors. Leveraging the strong frequency tunability of the couplers and stray interaction between the couplers and readout resonators, we eliminate state leakage on the couplers, thus suppressing space-correlated errors caused by population propagation among the couplers. Assisted by the couplers, we further reduce leakage to higher qubit levels with high efficiency (98.1%) and low error rate on the computational subspace (0.58%), suppressing time-correlated errors during QEC cycles. The performance of our scheme demonstrates its potential as an indispensable building block for scalable QEC with superconducting qubits.
Comment: 25 pages, 15 figures

الوصول الحر: http://arxiv.org/abs/2403.16155Test

المؤلفون: Huang, Shifeng, Jiang, Ning, Zhu, Jiazheng, Wang, Yibo, Wang, Tinggui, Wang, Shan-Qin, Gan, Wen-Pei, Liang, En-Wei, Qin, Yu-Jing, Lin, Zheyu, Xu, Lin-Na, Cai, Min-Xuan, Jiang, Ji-An, Kong, Xu, Li, Jiaxun, Li, Long, Wang, Jian-Guo, Xu, Ze-Lin, Xue, Yongquan, Yuan, Ye-Fei, Cheng, Jingquan, Fan, Lulu, Gao, Jie, Hu, Lei, Hu, Weida, li, Bin, Li, Feng, Liang, Ming, Liu, Hao, Liu, Wei, Lou, Zheng, Luo, Wentao, Qian, Yuan, Tang, Jinlong, Wan, Zhen, Wang, Hairen, Wang, Jian, Yang, Ji, Yao, Dazhi, Zhang, Hongfei, Zhang, Xiaoling, Zhao, Wen, Zheng, Xianzhong, Zhu, Qingfeng, Zuo, Yingxi

مصطلحات موضوعية: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies

الوصف: High-cadence, multiwavelength observations have continuously revealed the diversity of tidal disruption events (TDEs), thus greatly advancing our knowledge and understanding of TDEs. In this work, we conducted an intensive optical-UV and X-ray follow-up campaign of TDE AT2023lli, and found a remarkable month-long bump in its UV/optical light curve nearly two months prior to maximum brightness. The bump represents the longest separation time from the main peak among known TDEs to date. The main UV/optical outburst declines as $t^{-4.10}$, making it one of the fastest decaying optically selected TDEs. Furthermore, we detected sporadic X-ray emission 30 days after the UV/optical peak, accompanied by a reduction in the period of inactivity. It is proposed that the UV/optical bump could be caused by the self-intersection of the stream debris, whereas the primary peak is generated by the reprocessed emission of the accretion process. In addition, our results suggest that episodic X-ray radiation during the initial phase of decline may be due to the patched obscurer surrounding the accretion disk, a phenomenon associated with the inhomogeneous reprocessing process. The double TDE scenario, in which two stars are disrupted in sequence, is also a possible explanation for producing the observed early bump and main peak. We anticipate that the multicolor light curves of TDEs, especially in the very early stages, and the underlying physics can be better understood in the near future with the assistance of dedicated surveys such as the deep high-cadence survey of the 2.5-meter Wide Field Survey Telescope (WFST).
Comment: 14 pages, 8 figures,accepted for publication by ApJL

الوصول الحر: http://arxiv.org/abs/2403.01686Test

المؤلفون: Xiong, Yu, Hu, Zhipeng, Huang, Ye, Wu, Runze, Guan, Kai, Fang, Xingchen, Jiang, Ji, Zhou, Tianze, Hu, Yujing, Liu, Haoyu, Lyu, Tangjie, Fan, Changjie

مصطلحات موضوعية: Computer Science - Artificial Intelligence

الوصف: Reinforcement Learning (RL) has demonstrated substantial potential across diverse fields, yet understanding its decision-making process, especially in real-world scenarios where rationality and safety are paramount, is an ongoing challenge. This paper delves in to Explainable RL (XRL), a subfield of Explainable AI (XAI) aimed at unravelling the complexities of RL models. Our focus rests on state-explaining techniques, a crucial subset within XRL methods, as they reveal the underlying factors influencing an agent's actions at any given time. Despite their significant role, the lack of a unified evaluation framework hinders assessment of their accuracy and effectiveness. To address this, we introduce XRL-Bench, a unified standardized benchmark tailored for the evaluation and comparison of XRL methods, encompassing three main modules: standard RL environments, explainers based on state importance, and standard evaluators. XRL-Bench supports both tabular and image data for state explanation. We also propose TabularSHAP, an innovative and competitive XRL method. We demonstrate the practical utility of TabularSHAP in real-world online gaming services and offer an open-source benchmark platform for the straightforward implementation and evaluation of XRL methods. Our contributions facilitate the continued progression of XRL technology.
Comment: 10 pages, 5 figures

الوصول الحر: http://arxiv.org/abs/2402.12685Test

المؤلفون: Chen, Yan-Peng, Jiang, Ji-an, Luo, Wen-Tao, Zheng, Xian Zhong, Fang, Min, Yang, Chao, Hong, Yuan-Yu, Lv, Zong-Fei

مصطلحات موضوعية: Astrophysics - Instrumentation and Methods for Astrophysics

الوصف: Aiming at improving the survey efficiency of the Wide Field Survey Telescope, we have developed a basic scheduling strategy that takes into account the telescope characteristics, observing conditions, and weather conditions at the Lenghu site. The sky area is divided into rectangular regions, referred to as `tiles', with a size of 2.577 deg * 2.634 deg slightly smaller than the focal area of the mosaic CCDs. These tiles are continuously filled in annulars parallel to the equator. The brightness of the sky background, which varies with the moon phase and distance from the moon, plays a significant role in determining the accessible survey fields. Approximately 50 connected tiles are grouped into one block for observation. To optimize the survey schedule, we perform simulations by taking into account the length of exposures, data readout, telescope slewing, and all relevant observing conditions. We utilize the Greedy Algorithm for scheduling optimization. Additionally, we propose a dedicated dithering pattern to cover the gaps between CCDs and the four corners of the mosaic CCD array, which are located outside of the 3 deg field of view. This dithering pattern helps to achieve relatively uniform exposure maps for the final survey outputs.
Comment: 14 pages, 7 figures, 1 table. Accepted for pubulication in Research in Astronomy and Astrophysics

الوصول الحر: http://arxiv.org/abs/2312.03421Test

المؤلفون: Jiang, Ji, Cao, Meng, Song, Tengtao, Chen, Long, Wang, Yi, Zou, Yuexian

مصطلحات موضوعية: Computer Science - Computer Vision and Pattern Recognition, Computer Science - Computation and Language

الوصف: Video Referring Expression Comprehension (REC) aims to localize a target object in videos based on the queried natural language. Recent improvements in video REC have been made using Transformer-based methods with learnable queries. However, we contend that this naive query design is not ideal given the open-world nature of video REC brought by text supervision. With numerous potential semantic categories, relying on only a few slow-updated queries is insufficient to characterize them. Our solution to this problem is to create dynamic queries that are conditioned on both the input video and language to model the diverse objects referred to. Specifically, we place a fixed number of learnable bounding boxes throughout the frame and use corresponding region features to provide prior information. Also, we noticed that current query features overlook the importance of cross-modal alignment. To address this, we align specific phrases in the sentence with semantically relevant visual areas, annotating them in existing video datasets (VID-Sentence and VidSTG). By incorporating these two designs, our proposed model (called ConFormer) outperforms other models on widely benchmarked datasets. For example, in the testing split of VID-Sentence dataset, ConFormer achieves 8.75% absolute improvement on Accu.@0.6 compared to the previous state-of-the-art model.
Comment: Accepted to ACM International Conference on Multimedia Workshop (ACM MM), 2023. arXiv admin note: substantial text overlap with arXiv:2210.02953

الوصول الحر: http://arxiv.org/abs/2310.16402Test

المؤلفون: WFST Collaboration, Wang, Tinggui, Liu, Guilin, Cai, Zhenyi, Geng, Jinjun, Fang, Min, He, Haoning, Jiang, Ji-an, Jiang, Ning, Kong, Xu, Li, Bin, Li, Ye, Luo, Wentao, Pan, Zhizheng, Wu, Xuefeng, Yang, Ji, Yu, Jiming, Zheng, Xianzhong, Zhu, Qingfeng, Cai, Yi-Fu, Chen, Yuanyuan, Chen, Zhiwei, Dai, Zigao, Fan, Lulu, Fan, Yizhong, Fang, Wenjuan, He, Zhicheng, Hu, Lei, Hu, Maokai, Jin, Zhiping, Jiang, Zhibo, Li, Guoliang, Li, Fan, Li, Xuzhi, Liang, Runduo, Lin, Zheyu, Liu, Qingzhong, Liu, Wenhao, Liu, Zhengyan, Liu, Wei, Liu, Yao, Lou, Zheng, Qu, Han, Sheng, Zhenfeng, Shi, Jianchun, Shu, Yiping, Su, Zhenbo, Sun, Tianrui, Wang, Hongchi, Wang, Huiyuan, Wang, Jian, Wang, Junxian, Wei, Daming, Wei, Junjie, Xue, Yongquan, Yan, Jingzhi, Yang, Chao, Yuan, Ye, Yuan, Yefei, Zhang, Hongxin, Zhang, Miaomiao, Zhao, Haibin, Zhao, Wen

المصدر: SCPMA-Vol. 66 No. 10: 109512 (2023)

مصطلحات موضوعية: Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Astrophysics of Galaxies, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Solar and Stellar Astrophysics

الوصف: The Wide Field Survey Telescope (WFST) is a dedicated photometric surveying facility being built jointly by the University of Science and Technology of China and the Purple Mountain Observatory. It is equipped with a 2.5-meter diameter primary mirror, an active optics system, and a mosaic CCD camera with 0.73 gigapixels on the primary focal plane for high-quality image capture over an FOV of 6.5-square-degree. It is anticipated that WFST will be set up at the Lenghu site in the summer of 2023 and begin to observe the northern sky in four optical bands (u, g, r, and i) with a range of cadences, from hourly/daily in the Deep High-Cadence Survey (DHS) program to semiweekly in the Wide-Field Survey (WFS) program, three months later. During a photometric night, a nominal 30 s exposure in the WFS program will reach a depth of 22.27, 23.32, 22.84, and 22.31 (AB magnitudes) in these four bands, respectively, allowing for the detection of a tremendous amount of transients in the low-z universe and a systematic investigation of the variability of Galactic and extragalactic objects. In the DHS program, intranight 90 s exposures as deep as 23 (u) and 24 mag (g), in combination with target of opportunity follow-ups, will provide a unique opportunity to explore energetic transients in demand for high sensitivities, including the electromagnetic counterparts of gravitational wave events, supernovae within a few hours of their explosions, tidal disruption events and fast, luminous optical transients even beyond a redshift of unity. In addition, the final 6-year co-added images, anticipated to reach g=25.8 mag in WFS or 1.5 mags deeper in DHS, will be of fundamental importance to general Galactic and extragalactic science. The highly uniform legacy surveys of WFST will serve as an indispensable complement to those of LSST that monitor the southern sky.
Comment: 48 pages

الوصول الحر: http://arxiv.org/abs/2306.07590Test

المؤلفون: Jiang, Ji, Yan, Qipeng, Li, Ye, Lu, Min, Cui, Ziwei, Dou, Menghan, Wang, Qingchun, Wu, Yu-Chun, Guo, Guo-Ping

مصطلحات موضوعية: Quantum Physics

الوصف: It is the first step for understanding how RNA structure folds from base sequences that to know how its secondary structure is formed. Traditional energy-based algorithms are short of precision, particularly for non-nested sequences, while learning-based algorithms face challenges in obtaining high-quality training data. Recently, quantum annealer has rapidly predicted the folding of the secondary structure, highlighting that quantum computing is a promising solution to this problem. However, gate model algorithms for universal quantum computing are not available. In this paper, gate-based quantum algorithms will be presented, which are highly flexible and can be applied to various physical devices. Mapped all possible secondary structure to the state of a quadratic Hamiltonian, the whole folding process is described as a quadratic unconstrained binary optimization model. Then the model can be solved through quantum approximation optimization algorithm. We demonstrate the performance with both numerical simulation and experimental realization. Throughout our benchmark dataset, simulation results suggest that our quantum approach is comparable in accuracy to classical methods. For non-nested sequences, our quantum approach outperforms classical energy-based methods. Experimental results also indicate our method is robust in current noisy devices. It is the first instance of universal quantum algorithms being employed to tackle RNA folding problems, and our work provides a valuable model for utilizing universal quantum computers in solving RNA folding problems.
Comment: 19 pages, 7 figures

الوصول الحر: http://arxiv.org/abs/2305.09561Test

المؤلفون: Song, Tengtao, Chen, Nuo, Jiang, Ji, Zhu, Zhihong, Zou, Yuexian

مصطلحات موضوعية: Computer Science - Artificial Intelligence

الوصف: Multi-turn response selection is a challenging task due to its high demands on efficient extraction of the matching features from abundant information provided by context utterances. Since incorporating syntactic information like dependency structures into neural models can promote a better understanding of the sentences, such a method has been widely used in NLP tasks. Though syntactic information helps models achieved pleasing results, its application in retrieval-based dialogue systems has not been fully explored. Meanwhile, previous works focus on intra-sentence syntax alone, which is far from satisfactory for the task of multi-turn response where dialogues usually contain multiple sentences. To this end, we propose SIA, Syntax-Informed Attention, considering both intra- and inter-sentence syntax information. While the former restricts attention scope to only between tokens and corresponding dependents in the syntax tree, the latter allows attention in cross-utterance pairs for those syntactically important tokens. We evaluate our method on three widely used benchmarks and experimental results demonstrate the general superiority of our method on dialogue response selection.

الوصول الحر: http://arxiv.org/abs/2303.06605Test