近距離感染傳播的蒙特卡羅模擬研究 | 網絡科學論文速遞39篇


近距離感染傳播的蒙特卡羅模擬研究 | 網絡科學論文速遞39篇

2021-01-14 集智俱樂部

近距離感染傳播的蒙特卡羅模擬研究;高效運輸物流—- 奧地利城市貨運的一種途徑;使用變化中的變化模型,在選定的歐洲國家和美國,國家封鎖對新型冠狀病毒肺炎死亡的影響;監測政府干預以遏制新型冠狀病毒肺炎的影響: 一個定量的方法;集羣內和集羣間耦合平衡對非線性網絡系統性能的影響;美國、亞洲和歐洲新型冠狀病毒肺炎流行的時間數據系列表明,SARS-CoV-2 Spike D614G 變異具有選擇性;墨西哥的新型冠狀病毒肺炎: 流行病網絡;數據驅動的分析: 封鎖是否遏制了新型冠狀病毒肺炎在印度的傳播;森林砍伐與世界人口可持續性: 定量分析;時間依賴和時間獨立的 SIR 模型應用於在阿根廷、巴西、哥倫比亞、墨西哥和南非爆發的新型冠狀病毒肺炎;通風減少病毒傳播的必要性簡單量化; Lévy 漫步超擴散開始的普遍性起源;三維湍流中速度環流的概率分布;驅動諧振子的動力學耦合了隨機場中成對相互作用的伊辛自旋;基於光學偶極力阱釋放和捕獲的空氣微粒快速質量測定技術;滑動分析中的半柔性聚合物: 凹入轉變,轉換和活性的作用;異常的血小板運輸和脂肪尾分布;基於兩國連結追蹤抽樣的跨國社會領域測量;隱性衆包識別在線社交網絡中的濫用行爲;在黑暗網絡中挖掘用戶交互模式來預測企業網絡事件;用於檢索流量 Tweets 的自動查詢優化;利用圖形神經網絡學習傳染源的研究;(非)穩定網絡的 Nash 均衡;澳大利亞新型冠狀病毒肺炎流行引起的社區情緒動態研究;考慮私有節點的隨機漫步社會網絡性質估計;亞洲國家的風險溝通: 新型冠狀病毒肺炎在 Twitter 上的演講;當社會影響力促進羣體智慧時當社會影響力促進羣體智慧時;實驗耦合 logistic 映射中的分岔和滯後現象;在網絡化動態系統中識別有助於產生極端事件的邊界;進化油藏計算網絡中的功能差異;社會信任網絡中的意見最大化;監測新型冠狀病毒肺炎流感大流行下的全球情緒;基於資源分配的超邊界預測;青少年幸福感測量: 幼稚數字痕跡與調查數據的對應;自適應擴散下的多觀測謠言源檢測;心理物理學: 兩個耦合的正方形脈衝神經元在臨界狀態下具有巨大的動態範圍;英國新型冠狀病毒肺炎禁閉: 對空氣汙染有什麼影響;幾何,推理,複雜性和民主;使用概率細胞自動機研究計算模型新型冠狀病毒肺炎流行病;

原文標題:A Monte Carlo simulation study of proximity-based infection spread地址:

http://arxiv.org/abs/2006.12212

作者:

S. Triambak,D. P. Mahapatra

Abstract:Recent work showed that the initial COVID-19 data from China followed a subexponential power-law increase in the number of confirmed cases. This was attributed to a combination of effective containment and mitigation measures employed as well as behaviorial changes by the population. In view of this, we performed a Monte Carlo random walk study to better understand proximity-based infectious disease spread, particularly under restrictions. Our model is found to be rather robust and reproduces the observed power-law growth without relying on any external parameters. Three growth regimes (quadratic, power-law and exponential) emerge naturally from our simulations. These results suggest that the early containment of the disease within China was close to optimal and could not have been significantly improved upon. We show that reasonable agreement with other data can be attained by incorporating small-world-like connections in the simulations. The prescribed model and its generalizations might be useful for future strategies in the midst of the present pandemic.

摘要:最近的研究表明,來自中國的新型冠狀病毒肺炎衛生組織的初始數據顯示,確診病例的數量呈次指數冪律增長。這是由於採取了有效的遏制和緩解措施,以及人口的行爲變化。有鑑於此,我們進行了蒙特卡洛隨機漫步研究,以更好地理解基於鄰近的傳染病擴散,特別是在限制條件下。我們的模型是相當穩健的,並重現了觀察到的冪律增長而不依賴於任何外部參數。三種增長機制(二次型、冪律型和指數型)從我們的模擬中自然產生。這些結果表明,在中國早期遏制該病是接近最佳的,不可能有顯著改善。我們表明,合理的協議與其他數據可以通過納入小世界類似的連接模擬。這一規定的模式及其概括可能有助於在當前大流行期間制定今後的戰略。

原文標題:Efficient Transport Logistics, An Approach for Urban Freight Transport in Austria地址:

http://arxiv.org/abs/2006.11377

作者:

Verena Brandstätter,Cristina Olaverri-Monreal

Abstract:To alleviate traffic congestion that results from the growth of e-commerce we propose an approach in the city of Linz, Austria by relying on shared distribution centers from different companies. We develop two algorithms to find out the optimal location for the hubs and calculate the shortest path between locations. Results showed that in an urban environment, the implementation of hubs results in a reduction of the number of delivery vehicles. It reduces driving distances from hub to the customers, and also benefits the drivers that need to return home every day.

摘要:爲了減輕電子商務增長帶來的交通堵塞,我們提出了一種在奧地利林茨市通過依賴於不同公司的共享配送中心的方法。我們發展了兩個算法來找出樞紐的最佳位置和計算位置之間的最短路徑。結果表明,在城市環境中,建立樞紐導致運輸車輛數量減少。它縮短了從樞紐到客戶的行車距離,也使每天需要回家的司機受益。

使用變化中的變化模型,

在選定的歐洲國家和美國,

國家封鎖對新型冠狀

病毒肺炎死亡的影響

原文標題:Impact of national lockdown on COVID-19 deaths in select European countries and the US using a Changes-in-Changes model地址:

http://arxiv.org/abs/2006.12251

作者:

Mudit Kapoor,Shamika Ravi

Abstract:In this paper, we estimate the impact of national lockdown on COVID-19 related total and daily deaths, per million people, in select European countries. In particular, we compare countries that imposed a nationwide lockdown (Treatment group); Belgium, Denmark, France, Germany, Italy, Norway, Spain, United Kingdom (UK), and the US, to Sweden (Control group) that did not impose national lockdown using a changes-in-changes (CIC) estimation model. The key advantage of the CIC model as compared to the standard difference-in-difference model is that CIC allows for mean and variance of the outcomes to change over time in the absence of any policy intervention, and CIC accounts for endogeneity in the choice of policy intervention. Our results indicate that in contrast to Sweden, which did not impose a national lockdown, Germany, and to some extent, the US were the two countries where nationwide lockdown had a significant impact on the reduction in COVID-19 related total and daily deaths per million people. In Norway and Denmark, there was no significant impact on total and daily deaths per million people relative to Sweden. Whereas in other countries; Belgium, France, Italy, Spain, and the UK, the effect of the lockdown was in the opposite direction, that is, they experienced significantly higher COVID-19 related total and daily deaths per million people, post the lockdown as compared to Sweden. Our results suggest that the impact of nationwide lockdown on COVID-19 related total and daily deaths per million people varied from one country to another.

摘要:在這篇論文中,我們估計了國家防範禁閉對歐洲某些國家每天每百萬人中與新型冠狀病毒肺炎有關的總死亡人數和每日死亡人數的影響。特別是,我們將實施全國防範禁閉的國家(治療小組)、比利時、丹麥、法國、德國、義大利、挪威、西班牙、英國(英國)和美國與瑞典(控制小組)進行了比較,瑞典沒有使用變更估計模型(CIC)實施全國防範禁閉。與標準差異模型相比,CIC 模型的主要優勢在於,在沒有任何政策干預的情況下,CIC 允許結果的均值和方差隨時間而變化,CIC 解釋了政策干預選擇的內生性。我們的研究結果表明,與沒有實施全國防範禁閉的瑞典相比,德國和在某種程度上,美國是全國防範禁閉對減少與新型冠狀病毒肺炎有關的總死亡人數和每天每百萬人死亡人數有顯著影響的兩個國家。在挪威和丹麥,與瑞典相比,每百萬人的總死亡率和每日死亡率沒有顯著影響。然而在其他國家,比利時,法國,義大利,西班牙和英國,封鎖的影響是相反的方向,也就是說,他們經歷了明顯更高的與新型冠狀病毒肺炎有關的總數和每天每百萬人的死亡,比瑞典封鎖後。我們的研究結果表明,全國範圍內的封鎖對與新型冠狀病毒肺炎有關的總死亡人數和每天每百萬人的死亡人數的影響因國而異。

監測政府干預以遏制

新型冠狀病毒肺炎的影響: 

一個定量的方法


原文標題:Monitoring the Impacts of Government Interventions to Contain COVID-19: A Quantitative Approach地址:

https://arxiv.org/abs/2006.12177

作者:

Shuo Wang,Xian Yang,Yuan Huang,Ling Li,Zhongzhao Teng,Yike Guo

Abstract:Monitoring the evolving impacts of non-pharmaceutical intervention measures requires fine-grained estimation of transmission dynamics. We propose a framework to estimate instantaneous reproduction number R_t using Bayesian inference upon a renewal process, disentangling the R_t reduction into mitigation and suppression factors for quantifying their impacts at a finer granularity. Investigating the impacts of intervention measures of European countries, the United States and Wuhan with the framework, we reveal the effects of interventions in Europe and alert that 30 states in the United States are facing resurgence risks.

摘要:監測非藥物干預措施不斷變化的影響需要對傳播動態進行細緻的估計。我們提出了一個框架來估計瞬時再生數 r t,使用貝葉斯推斷在更新過程中,將 r t 約簡分解爲緩解和抑制因素,以便在更細的粒度上量化它們的影響。通過對歐洲國家、美國和武漢干預措施影響的框架調查,揭示了歐洲干預措施的效果,並警示美國30個州正面臨復甦風險。

原文標題:Impact of intra and inter-cluster coupling balance on the performance of nonlinear networked systems地址:

http://arxiv.org/abs/2006.11357

作者:

Jiachen Ye,Peng Ji,David Waxman,Wei Lin,Yamir Moreno

Abstract:The dynamical and structural aspects of cluster synchronization (CS) in complex systems have been intensively investigated in recent years. Here, we study CS of dynamical systems with intra and inter-cluster couplings. We propose new metrics that describe the performance of such systems and evaluate them as a function of the strength of the couplings within and between clusters. We obtain analytical results that indicate that spectral differences between the Laplacian matrices associated with the partition between intra and inter-couplings directly affect the proposed metrics of system performance. Our results show that the dynamics of the system might exhibit an optimal balance that optimizes its performance. Our work provides new insights into the way specific symmetry properties relate to collective behavior, and could lead to new forms to increase the controllability of complex systems and to optimize their stability.

摘要:近年來,人們對複雜系統中簇同步的動力學和結構性質進行了深入的研究。在這裡,我們研究了具有簇內和簇間耦合的動態系統的 CS。我們提出新的度量標準來描述這些系統的性能,並將它們作爲集羣內部和集羣之間耦合強度的函數來評估。我們得到的分析結果表明,譜差異之間的拉普拉斯矩陣相關的分割之間的內部和相互耦合直接影響系統性能的度量。我們的結果表明,系統的動態可能表現出一個最佳的平衡,以優化其性能。我們的工作對特定的對稱性質與集體行爲的關係提供了新的見解,並可能導致新的形式,以增加複雜系統的可控性和優化其穩定性。


美國、亞洲和歐洲新型冠狀病毒肺炎

流行的時間數據系列表明,

SARS-CoV-2 Spike D614G 變異

具有選擇性


原文標題:Temporal data series of COVID-19 epidemics in the USA, Asia and Europe suggests a selective sweep of SARS-CoV-2 Spike D614G variant地址:

http://arxiv.org/abs/2006.11609

作者:

Taima N. Furuyama,Fernando Antoneli,Isabel M. V. G. Carvalho,Marcelo R. S. Briones,Luiz M. R. Janini

Abstract:The COVID-19 pandemic started in Wuhan, China, and caused the worldwide spread of the RNA virus SARS-CoV-2, the causative agent of COVID-19. Because of its mutational rate, wide geographical distribution, and host response variance this coronavirus is currently evolving into an array of strains with increasing genetic diversity. Most variants apparently have neutral effects for disease spread and symptoms severity. However, in the viral Spike protein, which is responsible for host cell attachment and invasion, an emergent variant, containing the amino acid substitution D to G in position 614 (D614G), was suggested to increase viral infection capability. To test whether this variant has epidemiological impact, the temporal distributions of the SARS-CoV-2 samples bearing D or G at position 614 were compared in the USA, Asia and Europe. The epidemiological curves were compared at early and late epidemic stages. At early stages, where containment measures were still not fully implemented, the viral variants are supposed to be unconstrained and its growth curves might approximate the free viral dynamics. Our analysis shows that the D614G prevalence and the growth rates of COVID-19 epidemic curves are correlated in the USA, Asia and Europe. Our results suggest a selective sweep that can be explained, at least in part, by a propagation advantage of this variant, in other words, that the molecular level effects of D614G have sufficient impact on population transmission dynamics as to be detected by differences in rate coefficients of epidemic growth curves.

摘要:新型冠狀病毒肺炎病毒大流行始於中國武漢,引起了 RNA 病毒 SARS-CoV-2的全球傳播,SARS-CoV-2是新型冠狀病毒肺炎病毒的病原體。由於其突變率,廣泛的地理分布和宿主反應方差,這種冠狀病毒目前正在演變爲一系列的菌株增加遺傳多樣性。大多數變異顯然對疾病傳播和症狀嚴重性有中性影響。然而,在負責宿主細胞附著和侵襲的病毒穗蛋白中,一個突變體,在614位點(D614G)含有胺基酸替代的 d 到 g,提高了病毒的感染能力。爲了檢驗這一變異是否具有流行病學影響,我們比較了美國、亞洲和歐洲614位帶 d 或 g 的 SARS-CoV-2樣品的時間分布。比較了流行病學早期和晚期的流行曲線。在早期階段,遏制措施仍然沒有完全實施,病毒變異被認爲是不受約束的,它的生長曲線可能接近自由病毒動力學。我們的分析表明,在美國、亞洲和歐洲,D614G 流行率和新型冠狀病毒肺炎 / 愛滋病流行曲線的增長率是相關的。我們的研究結果表明,選擇性掃描至少可以部分地解釋這種變異的傳播優勢,換句話說,D614G 的分子水平效應對種羣傳播動力學有足夠的影響,可以通過流行病增長曲線速率係數的差異來檢測。

原文標題:COVID-19 in Mexico: A Network of Epidemics地址:

http://arxiv.org/abs/2006.11635

作者:

Guillermo de Anda-Jáuregui

Abstract:Mexico, like the rest of the world, is currently facing the The COVID-19 pandemic. Given the size of its territory, the efforts to contain the disease have involved both national and regional measures. For this work, the curves of daily new cases of each municipality reported by the federal government were compared. We found that 114 municipalities form a large network of statistically dependent epidemic phenomena. Based on the network’s modular structure, these 114 municipalities can be split into four distinct communities of coordinated epidemic phenomena. These clusters are not limited by geographical proximity. These findings can be helpful for public health officials for the evaluation of past strategies and the development of new directed interventions.

摘要:墨西哥和世界其他地區一樣,目前正面臨新型冠狀病毒肺炎流感大流行。鑑於其領土面積之大,控制該疾病的努力涉及國家和區域措施。對於這項工作,每個市政府報告的每日新病例曲線進行了比較。我們發現,114個城市形成了一個龐大的網絡統計依賴的流行病現象。根據網絡的模塊結構,這114個城市可以分爲四個不同的協調流行現象社區。這些集羣不受地理鄰近性的限制。這些發現可以幫助公共衛生官員評估過去的戰略和發展新的指導干預措施。


數據驅動的分析: 

封鎖是否遏制了

新型冠狀病毒肺炎在印度的傳播

原文標題:Did the lockdown curb the spread of COVID-19 infection rate in India: A data-driven analysis地址:

http://arxiv.org/abs/2006.12006

作者:

Dipankar Mondal,Siddhartha P. Chakrabarty

Abstract:In order to analyze the effectiveness of three successive nationwide lockdown enforced in India, we present a data-driven analysis of four key parameters, reducing the transmission rate, restraining the growth rate, flattening the epidemic curve and improving the health care system. These were quantified by the consideration of four different metrics, namely, reproduction rate, growth rate, doubling time and death to recovery ratio. The incidence data of the COVID-19 (during the period of 2nd March 2020 to 31st May 2020) outbreak in India was analyzed for the best fit to the epidemic curve, making use of the exponential growth, the maximum likelihood estimation, sequential Bayesian method and estimation of time-dependent reproduction. The best fit (based on the data considered) was for the time-dependent approach. Accordingly, this approach was used to assess the impact on the effective reproduction rate. The period of pre-lockdown to the end of lockdown 3, saw a45% reduction in the rate of effective reproduction rate. During the same period the growth rate reduced from 393% during the pre-lockdown to 33% after lockdown 3, accompanied by the average doubling time increasing form 4-6 days to 12-14 days. Finally, the death-to-recovery ratio dropped from 0.28 (pre-lockdown) to 0.08 after lockdown 3. In conclusion, all the four metrics considered to assess the effectiveness of the lockdown, exhibited significant favourable changes, from the pre-lockdown period to the end of lockdown 3. Analysis of the data in the post-lockdown period with these metrics will provide greater clarity with regards to the extent of the success of the lockdown.

摘要:爲了分析印度連續三次全國性封鎖的有效性,我們提出了四個關鍵參數的數據驅動分析,降低傳播率,抑制增長率,平緩流行曲線和改善衛生保健系統。這些被量化的考慮四個不同的指標,即繁殖率,生長率,倍增時間和死亡恢復率。對印度新型冠狀病毒肺炎爆發的發病率數據(2020年3月2日至2020年5月31日期間)進行了分析,以尋找與疫情曲線的最佳擬合,利用指數增長、最大似然估計、序貫貝葉斯方法和時間依賴性繁殖的估計。最佳擬合(基於所考慮的數據)是時間相關的方法。因此,這種方法被用來評估對有效繁殖率的影響。從禁閉前到禁閉3結束的這段時間裡45% 有效繁殖率下降。在同一時期,生長率從393% 在禁閉前33% 在禁閉3號之後,伴隨著平均倍增時間的形式 4-6 天到12-14 天最後,死亡與康復的比率從0.28 到0.08 。在3號禁閉室之後。總而言之,所有評估封鎖有效性的四個指標,從封鎖前期到封鎖3結束,都表現出了顯著的有利變化。使用這些指標對封鎖後期間的數據進行分析,可以更清楚地了解封鎖的成功程度。

原文標題:Deforestation and world population sustainability: a quantitative analysis地址:

http://arxiv.org/abs/2006.12202

作者:

Mauro Bologna,Gerardo Aquino

Abstract:In this paper we afford a quantitative analysis of the sustainability of current world population growth in relation to the parallel deforestation process adopting a statistical point of view. We consider a simplified model based on a stochastic growth process driven by a continuous time random walk, which depicts the technological evolution of human kind, in conjunction with a deterministic generalised logistic model for humans-forest interaction and we evaluate the probability of avoiding the self-destruction of our civilisation. Based on the current resource consumption rates and best estimate of technological rate growth our study shows that we have very low probability, less than 10% in most optimistic estimate, to survive without facing a catastrophic collapse.

摘要:本文採用統計學的觀點,對當前世界人口增長與平行毀林過程的可持續性進行了定量分析。我們考慮了一個簡化的模型,該模型基於連續時間隨機遊走驅動的隨機增長過程,描述了人類的技術進化,並結合一個確定性的廣義邏輯斯諦模型來描述人類與森林的相互作用,我們評估了避免人類文明自我毀滅的可能性。基於當前的資源消耗率和對技術增長率的最佳估計,我們的研究表明,我們在不面臨災難性崩潰的情況下生存的概率非常低,最樂觀的估計不到10%。


時間依賴和時間獨立的 SIR 模型

應用於在阿根廷、巴西、哥倫比亞、

墨西哥和南非爆發的新型冠狀病毒肺炎

原文標題:Time-dependent and time-independent SIR models applied to the COVID-19 outbreak in Argentina, Brazil, Colombia, Mexico and South Africa地址:

https://arxiv.org/abs/2006.12479

作者:

Nana Geraldine Cabo Bizet,Damián Kaloni Mayorga Peña

Abstract:We consider the SIR epidemiological model applied to the evolution of COVID-19 with two approaches. In the first place we fit a global SIR model, with time delay, and constant parameters throughout the outbreak, including the contagion rate. The contention measures are reflected on an effective reduced susceptible populationNeff. In the second approach we consider a time-dependent contagion rate that reflects the contention measures either through a step by step fitting process or by following an exponential decay. In this last model the population is considered the one of the country N. In the linear region of the differential equations, when the total population N is large the predictions are independent of N. We apply these methodologies to study the spread of the pandemic in Argentina, Brazil, Colombia, Mexico, and South Africa for which the infection peaks are yet to be reached. In all of these cases we provide estimates for the reproduction and recovery rates. The scenario for a time varying contagion rate is optimistic, considering that reasonable measures are taken such that the reproduction factor R0 decreases exponentially. The measured values for the recovery rate γ are reported finding a universality of this parameter over various countries. We discuss the correspondence between the global SIR with effective population Neff and the evolution of the time local SIR.

摘要:我們考慮用兩種方法將 SIR 流行病學模型應用於 covid-19的進化。首先,我們擬合一個全局 SIR 模型,具有時間延遲,並且在整個爆發過程中參數不變,包括傳染率。爭奪措施反映在有效減少易感種羣上Neff. 在第二種方法中,我們考慮一個依賴於時間的傳染率,它通過一個逐步擬合的過程或者遵循一個指數衰減來反映爭論的度量。在最後一個模型中,人口被認爲是國家的一部分N.我們應用這些方法來研究這種流行病在阿根廷、巴西、哥倫比亞、墨西哥和南非的傳播情況,這些國家的感染高峯尚未到來。在所有這些情況下,我們提供了複製和恢復率的估計。考慮到採取了合理的措施,使再生產因素得以保留,時變傳染率的假設是樂觀的R0 回收率的測量值γ ,本文報導了這個參數在各國的普適性,並討論了全局 SIR 與有效總體之間的對應關係Neff 以及時間演變的本地 SIR。

原文標題:Necessity of ventilation for mitigating virus transmission quantified simply地址:

http://arxiv.org/abs/2006.11651

作者:

Eric G. Blackman,Gourab Ghoshal

Abstract:To mitigate the SARS-CoV-2 pandemic, officials have employed social distancing and stay-at-home measures. Less attention has focused on ventilation. Effective distancing practices for open spaces may be ineffective for poorly ventilated spaces, both of which are commonly filled with turbulent air. While turbulence initially reduces the risk of infection near a virion-source, it eventually increases the exposure risk for all occupants in a space without ventilation. Here we estimate the time-scale for virions injected into a room of turbulent air to infect an occupant, distinguishing cases of low vs. high initial virion mass loads and virion-destroying vs. virion-reflecting walls. An open window typifies ventilation and we show that its minimum area needed to ensure safety depends only on the ratio of total viral load to threshold load for infection. Our order-of-magnitude estimates complement more detailed approaches.

摘要:爲了緩解 SARS-CoV-2大流行,官員們採用了社會疏遠和居家措施。人們很少關注通風問題。開放空間的有效距離做法可能對通風不良的空間無效,這兩個空間通常都充滿了湍流空氣。雖然湍流最初會降低病毒源附近感染的風險,但最終會增加沒有通風設備的空間中所有居住者的暴露風險。在這裡,我們估計時間尺度的病毒注入一個房間的湍流空氣感染一個居住者,區分情況低與高初始病毒質量負荷和病毒破壞與病毒反射牆。開窗通氣是典型的通氣方式,我們發現確保通氣安全所需的最小面積僅取決於病毒載量與感染閾值載量的比值。我們的數量級估計補充了更詳細的方法。

原文標題:The origin of universality in the onset of superdiffusion in Lévy walks地址:

http://arxiv.org/abs/2006.11932

作者:

Asaf Miron

Abstract:Superdiffusion arises when complicated, correlated and noisy motion at the microscopic scale conspires to yield peculiar dynamics at the macroscopic scale. It ubiquitously appears in a variety of scenarios, spanning a broad range of scientific disciplines. The approach of superdiffusive systems towards their long-time, asymptotic behavior was recently studied using the Lévy walk of order1<β<2, revealing a universal transition at the critical βc=3/2. Here, we investigate the origin of this transition and identify two crucial ingredients: a finite velocity which couples the walker's position to time and a corresponding transition in the fluctuations of the number of walks n completed by the walker at time t.

摘要:當微觀尺度的複雜、相關和嘈雜的運動在宏觀產生奇特的動力學時,就會產生超擴散。它無處不在地出現在各種各樣的場景中,跨越了廣泛的科學分支。研究了超擴散系統長時間漸近行爲的逼近問題1<β<2,本文通過對中國傳統文化的分析,揭示了中國傳統文化在關鍵時刻的普遍轉變,並對中國傳統文化的發展提出了建議βc=3/2.在這裡,我們研究了這種轉變的起源,並確定了兩個關鍵因素: 有限速度與步行者的位置關聯到時間,以及相應的步行次數波動的轉變n 由行駛完成的t。

原文標題:Probability Distribution of Velocity Circulation in Three Dimensional Turbulence地址:

http://arxiv.org/abs/2006.12008

作者:

Alexander Migdal

Abstract:We elaborate the statistical field theory of Turbulence suggested in the previous paper cite{M20a}. We clarify and simplify the basic Energy pumping equation of that theory and study mathematical properties of singular field configuration (instanton) which determine the tails of PDF for the velocity circulation around large loopC in isotropic turbulence at highest Reynolds numbers. Explicit analytic solution is found for the Clebsch instanton in an Euler equation for a planar loop circulation problem. This solution for vorticity is has a term proportional to a delta function in normal direction to the minimal surface bounded by the loop. The smoothing of δ functions in the vorticity in the full Navier-Stokes equations is investigated and exponential profile of smoothed singularity is found.
The PDF for circulation is now an infinite sum of decreasing exponential terms $EXP{- n |w|}sqrt{frac{n}{|w|}}$, with w=ΓΓ0[C], and Γ0[C]∼AC−−−√ with minimal area AC. The leading term fits with adjusted R2=0.9999 the PDF tail found in DNS over more than six orders of magnitude. The area dependence of the ratio of the circulation moments M8/M6 fits with adjusted R2=0.9996 the DNS in inertial range of square loop sizes from 100 to 500 Kolmogorov scales.
Thus, our theory explains DNS with high degree or confidence.
For a flat loop we derive two-dimensional integral equation for the dependence of the scale Γ0[C] of circulation as a function of the shape of the loop (aspect ratio for rectangular loop

摘要:對前人提出的湍流統計場理論進行了詳細的闡述。闡明和簡化了該理論的基本能量抽運方程,並研究了決定大迴路周圍速度環流概率密度函數(PDF)尾部的奇異場結構(瞬子)的數學性質C 在各向同性湍流中達到最高雷諾數。給出了平面環路環流問題歐拉方程中克萊布施瞬子的顯式解析解。這個渦量的解決方案是有一個項成正比的三角函數在法向的最小曲面有界的迴路。平滑δ 研究了全納維-斯托克斯方程渦量中的函數,發現了光滑奇點的指數分布。

發行量的 PDF 現在是指數遞減項的無窮和 $EXP {-n | w | | } sqrt { frac { n }{ | w | } $和w=ΓΓ0[C],及Γ0[C]∼AC−−−√ 最小面積AC.主要的術語適合調整R2=0.9999 。在超過6個數量級的時間內在 DNS 中定位 PDF。環流矩比值的面積相關性M8/M6 與調整過的吻合R2=0.9996 慣性範圍內的正方形迴路尺寸的 dn100 到500 柯爾莫哥洛夫尺度。因此,我們的理論對 DNS 的解釋具有高度的可信度。

對於一個平面環,我們推導出尺度依賴性的二維積分方程Γ0[C] 矩形環的長寬比。


驅動諧振子的動力學耦合了

隨機場中成對相互作用的伊辛自旋


原文標題:The dynamics of a driven harmonic oscillator coupled to pairwise interacting Ising spins in random fields地址:

http://arxiv.org/abs/2006.12429

作者:

Paul Zech,Andreas Otto,Günter Radons

Abstract:In general we are interested in dynamical systems coupled to complex hysteresis. Therefore as a first step we did some investigation on the dynamics of a periodically driven damped harmonic oscillator coupled to independent Ising spins with a local quenched disorder at zero temperature in the past. Although such a system does not produce hysteresis, we showed how to characterize the dynamics of such a piecewise-smooth system, specially in case of a large number of spins [P. Zech, A. Otto, and G. Radons, Phys. Rev. E101,042217 (2020)]. In this paper we want to extend our model to spins dimers, thus spins with pairwise interaction. We will show in which cases two interacting spins can show elementary hysteresis and we will give a connection to the ac{PM}, when superpose a infinite number of spin-pairs in the thermodynamic limit. We will see, that this will lead us to a dynamical system with an additional hysteretic force in form of a play operator. By using methods from general chaos theory, piecewise-smooth system theory and statistics we will investigate the chaotic behavior of the dynamical system for a few spins and also in case of larger number of spins by calculating bifurcation diagrams, fractal dimensions and self-averaging properties. In doing so we show, how the dynamical properties of the piecewise-smooth system for a large number of spins differs from the system in its thermodynamic limit.

摘要:一般來說,我們感興趣的動力系統耦合的複雜滯後。因此,作爲第一步,我們做了一些動力學的研究,周期性驅動的阻尼諧振子與獨立的伊辛自旋耦合,在過去的零溫下局部淬火無序。雖然這樣一個系統不產生滯後,我們展示了如何刻畫這樣一個分段光滑系統的動力學性質,特別是在大量自旋的情況下[ p. Zech,a. Otto,和 g. Radons,Phys。101,042217(2020)]. 在這篇論文中,我們希望將我們的模型擴展到自旋二聚體,從而使自旋具有成對相互作用。我們將展示在哪些情況下相互作用的自旋可以顯示出基本的滯後現象,並且我們將給出與 ac { PM }的聯繫,當無限多的自旋對疊加在熱力學極限中時。我們將看到,這將引導我們到達一個帶有額外的滯後力的動力系統。利用一般混沌理論、分段光滑系統理論和統計學的方法,通過計算分叉圖、分形維數和自平均特性,研究了動力系統在少數自旋和大自旋情況下的混沌行爲。在這個過程中,我們展示了大量自旋的分段光滑系統的動力學性質與其自旋熱力學極限的不同之處。


基於光學偶極力阱釋放和捕獲

的空氣微粒快速質量測定技術

原文標題:Technique for rapid mass determination of airborne micro-particles based on release and recapture from an optical dipole force trap地址:

http://arxiv.org/abs/2006.12429

作者:

Gehrig Carlse,Kevin B. Borsos,Hermina C. Beica,Thomas Vacheresse,Alex Pouliot,Jorge Perez-Garcia,Andrejs Vorozcovs,Boris Barron,Shira Jackson,Louis Marmet,A. Kumarakrishnan

AbstractWe describe a new method for the rapid determination of the mass of particles confined in a free-space optical dipole-force trap. The technique relies on direct imaging of drop-and-restore experiments without the need for a vacuum environment. In these experiments, the trapping light is rapidly shuttered with an acousto-optic modulator causing the particle to be released from and subsequently recaptured by the trapping force. The trajectories of both the falls and restorations, imaged using a high-speed CMOS sensor, are combined to determine the particle mass. We corroborate these measurements using an analysis of position autocorrelation functions of the trapped particles. We report a statistical uncertainty of less than 2% for masses on the order of5×10−14 kg using a data acquisition time of approximately 90 seconds.

摘要:本文介紹了一種快速測定自由空間光學偶極力阱中粒子質量的新方法。該技術依賴於直接成像的跌落和恢復實驗,而不需要一個真空環境。在這些實驗中,捕獲光被聲光調製器快速關閉,粒子被釋放出來,隨後被捕獲力重新捕獲。利用一個高速 CMOS 傳感器成像,將跌落和修復的軌跡結合起來,以確定粒子的質量。我們通過分析囚禁粒子的位置自相關函數來證實這些測量結果。我們報告的統計不確定性小於2% 的羣衆的秩序5×10−14 kg,使用大約90秒的數據採集時間。


滑動分析中的半柔性聚合物:

凹入轉變,轉換和活性的作用


原文標題:Semiflexible polymer in a gliding assay: reentrant transition, role of turnover and activity地址:

http://arxiv.org/abs/2006.11603

作者:

Amir Shee,Nisha Gupta,Abhishek Chudhuri,Debasish Chaudhuri

Abstract:We consider a model of an extensible semiflexible filament moving in two dimensions on a motility assay of motor proteins represented explicitly as active harmonic linkers. Their heads bind stochastically to polymer segments within a capture radius, and extend along the filament in a directed fashion before detaching. Both the extension and detachment rates are load-dependent and generate an active drive on the filament. The filament undergoes a first order phase transition from open chain to spiral conformations and shows a reentrant behavior in both the active extension and the turnover, defined as the ratio of attachment-detachment rates. Associated with the phase transition, the size and shape of the polymer changes non-monotonically, and the relevant autocorrelation functions display double-exponential decay. The corresponding correlation times show a maximum signifying the dominance of spirals. The orientational dynamics captures the rotation of spirals, and its correlation time decays with activity as a power law.

摘要:我們考慮一個可擴展的半柔性燈絲在二維運動的模型上的運動測定的馬達蛋白顯式表示爲活躍的諧波連接器。它們的頭隨機地綁在捕獲半徑範圍內的聚合物環節上,在分離之前沿著細絲定向延伸。伸展速率和分離速率都與載荷有關,並在燈絲上產生主動驅動。絲狀體經歷了從開鏈到螺旋構象的一級相變過程,在有效擴展和周轉過程中都表現出重入行爲,這種行爲被定義爲附著-分離率的比值。聚合物的尺寸和形狀隨相變呈非單調變化,相應的自相關函數呈雙指數衰減。相應的相關時間顯示了螺旋占主導地位的最大值。定向動力學捕獲螺旋旋轉,其相關時間隨活動呈冪律衰減。

原文標題:Anomalous Platelet Transport & Fat-Tailed Distributions地址:

http://arxiv.org/abs/2006.11755

作者:

Christos Kotsalos,Karim Zouaoui Boudjeltia,Ritabrata Dutta,Jonas Latt,Bastien Chopard

Abstract:The transport of platelets in blood is commonly assumed to obey an advection-diffusion equation. Here we propose a disruptive view, by showing that the random part of their velocity is governed by a fat-tailed probability distribution, usually referred to as a L’evy flight. Although for small spatio-temporal scales, it is hard to distinguish it from the generally accepted “red blood cell enhanced” Brownian motion, for larger systems this effect is dramatic as the standard approach may underestimate the flux of platelets by several orders of magnitude, compromising in particular the validity of current platelet function tests.

摘要:血小板在血液中的運輸通常被認爲遵循一個平流-擴散方程。在這裡,我們提出了一個破壞性的觀點,通過展示它們速度的隨機部分是由厚尾概率分布控制的,通常被稱爲 l『 evy 飛行。雖然對於小的時空尺度,很難區分它與普遍接受的「紅細胞增強」布朗運動,對於較大的系統,這種效應是戲劇性的,因爲標準的方法可能低估血小板的流量幾百萬數量級,特別是降低了當前血小板功能測試的有效性。


原文標題:
Measuring transnational social fields through binational link-tracing sampling地址:

https://arxiv.org/abs/2006.11380

作者:

Marian-Gabriel Hâncean,Miranda J. Lubbers,José Luis Molina

Abstract:We advance binational link-tracing sampling design, an innovative data collection methodology for sampling from transnational social fields, i.e., transnational networks embedding migrants and non-migrants. This paper shows the practical challenges of such a design, the representativeness of the samples and the qualities of the resulted networks. We performed 303 face-to-face structured interviews on sociodemographic variables, migration trajectories and personal networks of people living in a Romanian migration sending community (Dâmboviţa) and in a migration receiving Spanish town (Castellón), simultaneously in both sites. Inter-connecting the personal networks, we built a multi-layered complex network structure embedding 4,855 nominated people, 5,477 directed ties (nominations) and 2,540 edges. Results indicate that the participants’ unique identification is a particularly difficult challenge, the representativeness of the data is not optimal (homophily on observed attributes was detected in the nomination patterns), and the relational and attribute data allow to explore the social organization of the Romanian migrant enclave in Castellón, as well as its connectivity to other places. Furthermore, we provide methodological suggestions for improving link-tracing sampling from transnational networks of migration. Our research contributes to the emerging efforts of applying social network analysis to the study of international migration.

摘要:我們提出了兩國連結追蹤抽樣設計,這是一種創新的數據收集方法,用於跨國社會領域的抽樣,即包含移民和非移民的跨國網絡。本文指出了這種設計的實際挑戰,樣本的代表性和由此產生的網絡的質量。我們進行了303次面對面的結構化訪談,內容涉及社會人口變量、移民軌跡和個人網絡,這些人生活在羅馬尼亞移民輸出社區(d ^ ambovi c { t } a)和移民接收西班牙城鎮(Castell『 on) ,同時在這兩個地點進行。通過個人網絡的相互連接,我們建立了一個多層次的複雜網絡結構,包括4855個提名人,5477個有向聯繫(提名)和2540個邊。結果表明,參與者的獨特身份識別是一個特別困難的挑戰,數據的代表性不是最佳的(在提名模式中發現了觀察到的屬性的同相性) ,關係和屬性數據允許探索 Castell『 on 羅馬尼亞移民飛地的社會組織及其與其他地方的連通性。此外,我們還爲改進跨國移民網絡中的連結追蹤抽樣提供了方法上的建議。我們的研究有助於將社會網絡分析應用於國際移民研究。

原文標題:Implicit Crowdsourcing for Identifying Abusive Behavior in Online Social Networks地址:

https://arxiv.org/abs/2006.11456

作者:

Abiola Osho,Ethan Tucker,George Amariucai

Abstract:The increased use of online social networks for the dissemination of information comes with the misuse of the internet for cyberbullying, cybercrime, spam, vandalism, amongst other things. To proactively identify abuse in the networks, we propose a model to identify abusive posts by crowdsourcing. The crowdsourcing part of the detection mechanism is implemented implicitly, by simply observing the natural interaction between users encountering the messages. We explore the node-to-node spread of information on Twitter and propose a model that predicts the abuse level (abusive, hate, spam, normal) associated with the tweet by observing the attributes of the message, along with those of the users interacting with it. We demonstrate that the difference in users’ interactions with abusive posts can be leveraged in identifying posts of varying abuse levels.

摘要:隨著在線社交網絡用於信息傳播的增加,網絡被濫用於網絡欺凌、網絡犯罪、垃圾郵件、破壞公物等等。爲了主動識別網絡中的濫用行爲,我們提出了一個通過衆包識別濫用帖子的模型。檢測機制的衆包部分是隱式實現的,通過簡單地觀察遇到消息的用戶之間的自然交互。我們研究了 Twitter 上信息的節點到節點的傳播,並提出了一個模型,通過觀察消息的屬性以及與之交互的用戶的屬性,來預測與該消息相關的濫用程度(辱罵、仇恨、垃圾郵件、正常)。我們證明,用戶與濫發帖子互動的差異可以用來識別不同程度的濫用帖子。

原文標題:Mining user interaction patterns in the darkweb to predict enterprise cyber incidents地址:

https://arxiv.org/abs/1909.11592

作者:

Soumajyoti Sarkar,Mohammad Almukaynizi,Jana Shakarian,Paulo Shakarian

Abstract:With rise in security breaches over the past few years, there has been an increasing need to mine insights from social m。edia platforms to raise alerts of possible attacks in an attempt to defend conflict during competition. In this study, we attempt to build a framework that utilizes unconventional signals from the darkweb forums by leveraging the reply network structure of user interactions with the goal of predicting enterprise related external cyber attacks. We use both unsupervised and supervised learning models that address the challenges that come with the lack of enterprise attack metadata for ground truth validation as well as insufficient data for training the models. We validate our models on a binary classification problem that attempts to predict cyber attacks on a daily basis for an organization. Using several controlled studies on features leveraging the network structure, we measure the extent to which the indicators from the darkweb forums can be successfully used to predict attacks. We use information from 53 forums in the darkweb over a span of 17 months for the task. Our framework to predict real world organization cyber attacks of 3 different security events, suggest that focusing on the reply path structure between groups of users based on random walk transitions and community structures has an advantage in terms of better performance solely relying on forum or user posting statistics prior to attacks.

摘要:在過去的幾年裡,隨著數字證書認證機構數量的上升,人們越來越需要從社交媒體平台中挖掘洞察力,提高對可能發生的攻擊的警報,以便在競爭中保護衝突。在這項研究中,我們嘗試建立一個框架,利用黑暗網絡論壇的非常規信號,利用用戶交互的回覆網絡結構,以預測企業相關的外部網絡攻擊。我們同時使用無監督模型和監督式學習模型來解決缺乏企業攻擊元數據進行實地驗證以及培訓模型的數據不足所帶來的挑戰。我們在一個二元分類問題上驗證了我們的模型,該問題試圖每天爲組織預測網絡攻擊。通過對網絡結構特徵的一些受控研究,我們測量了來自黑暗網絡論壇的指標能夠成功用於預測攻擊的程度。我們在17個月的時間裡使用了53個論壇的暗網信息來完成這項任務。我們的框架預測現實世界組織的3個不同的安全事件的網絡攻擊,建議關注用戶組之間的回覆路徑結構基於隨機漫步過渡和社區結構的優勢在於更好的性能完全依賴於論壇或用戶發布攻擊前的統計數據。

原文標題:Automatic Query Optimization for Retrieving Traffic Tweets地址:

https://arxiv.org/abs/2006.11887

作者:

Emory Hufbauer,Hana Khamfroush

Abstract:Twitter, like many social media and data brokering companies, makes their data available through a search API (application programming interface). In addition to filtering results by date and location, researchers can search for tweets with specific content with a boolean text query, using {it AND}, {it OR}, and {it NOT} operators to select the combinations of phrases which must, or must not, appear in matching tweets. This boolean text search system is not at all unique to Twitter and is found in many different contexts, including academic, legal, and medical databases, however it is stretched to its limits in Twitter’s use case because of the relative volume and brevity of tweets. In addition, the semi-automated use of such systems was well studied under the topic of Information Retrieval during the 1980s and 1990s, however the study of such systems has greatly declined since that time. As such, we propose updated methods for automatically selecting and refining complex boolean search queries that can isolate relevant results with greater specificity and completeness. Furthermore, we present preliminary results of using an optimized query to collect a sample of traffic-incident-related tweets, along with the results of manually classifying and analyzing them.

摘要:像許多社交媒體和數據代理公司一樣,Twitter 通過一個搜索 API (應用程式編程接口)提供數據。除了按日期和位置過濾結果,研究人員還可以通過布爾文本查詢搜索具有特定內容的 tweets,使用{ it AND }、{ it OR }和{ it NOT }操作符來選擇必須或不能出現在匹配 tweets 中的短語組合。這個布爾型文本搜索系統並不是 Twitter 獨有的,可以在很多不同的環境中找到,包括學術、法律和醫療資料庫,然而在 Twitter 的使用案例中,由於推文的相對數量和簡潔性,它已經達到了極限。此外,在20世紀80年代和90年代,這種系統的半自動化使用在信息檢索的主題下得到了很好的研究,然而自那時以來,這種系統的研究已經大大減少了。因此,我們提出了更新的方法,自動選擇和精煉複雜的布爾搜索查詢,可以隔離相關的結果更具有特異性和完整性。此外,我們提出了初步的結果,使用優化的查詢收集交通事件相關的 tweets 樣本,以及手動分類和分析的結果。

原文標題:Finding Patient Zero: Learning Contagion Source with Graph Neural Networks地址:

https://arxiv.org/abs/2006.11913

作者:

Chintan Shah,Nima Dehmamy,Nicola Perra,Matteo Chinazzi,Albert-László Barabási,Alessandro Vespignani,Rose Yu

Abstract:Locating the source of an epidemic, or patient zero (P0), can provide critical insights into the infection’s transmission course and allow efficient resource allocation. Existing methods use graph-theoretic centrality measures and expensive message-passing algorithms, requiring knowledge of the underlying dynamics and its parameters. In this paper, we revisit this problem using graph neural networks (GNNs) to learn P0. We establish a theoretical limit for the identification of P0 in a class of epidemic models. We evaluate our method against different epidemic models on both synthetic and a real-world contact network considering a disease with history and characteristics of COVID-19. % We observe that GNNs can identify P0 close to the theoretical bound on accuracy, without explicit input of dynamics or its parameters. In addition, GNN is over 100 times faster than classic methods for inference on arbitrary graph topologies. Our theoretical bound also shows that the epidemic is like a ticking clock, emphasizing the importance of early contact-tracing. We find a maximum time after which accurate recovery of the source becomes impossible, regardless of the algorithm used.

摘要:找到流行病的源頭,或者說零號病人(P0) ,可以對感染的傳播過程提供關鍵的洞察力,從而實現有效的資源配置。現有的方法使用圖論中心性度量和代價高昂的消息傳遞算法,需要了解底層動態及其參數。本文利用圖神經網絡(GNNs)學習 P0,重新研究了這個問題。建立了一類傳染病模型中 P0判別的理論極限。我們評估我們的方法針對不同的傳染病模型在合成和現實世界接觸網絡考慮一個疾病的歷史和特點的新型冠狀病毒肺炎。我們觀察到 GNNs 能夠識別接近理論界限的精度,沒有明確的輸入動力學或其參數。此外,GNN 比傳統的圖拓撲推理方法快100倍以上。我們的理論界限還表明,這種流行病就像一個滴答作響的時鐘,強調了早期接觸追蹤的重要性。我們發現一個最大的時間之後,準確恢復源變得不可能,無論使用的算法。

原文標題:Nash Equilibria on (Un)Stable Networks地址:

https://arxiv.org/abs/1901.00373

作者:

Anton Badev

Abstract:In response to a change, individuals may choose to follow the responses of their friends or, alternatively, to change their friends. To model these decisions, consider a game where players choose their behaviors and friendships. In equilibrium, players internalize the need for consensus in forming friendships and choose their optimal strategies on subsets of k players – a form of bounded rationality. The k-player consensual dynamic delivers a probabilistic ranking of a game’s equilibria, and, via a varying k, facilitates estimation of such games. Applying the model to adolescents’ smoking suggests that: (a.) the response of the friendship network to changes in tobacco price amplifies the intended effect of price changes on smoking, (b.) racial desegregation of high-schools decreases the overall smoking prevalence, (c.) peer effect complementarities are substantially stronger between smokers compared to between non-smokers. (d.) the magnitude of the spillover effects from small scale policies targeting individuals’ smoking choices are roughly double compared to the scale of these policies.

摘要:作爲對變化的回應,個體可能會選擇跟隨他們朋友的回應,或者,改變他們的朋友。爲了建立這些決定的模型,考慮一個遊戲,其中玩家選擇他們的行爲和友誼。在均衡狀態下,玩家在建立友誼時內在地需要達成共識,並在 k 個玩家子集上選擇他們的最佳策略,這是一種有限理性的形式。K- 玩家一致同意動態提供了一個遊戲均衡的概率排名,並通過變化的 k,促進了這類遊戲的估計。將該模型應用於青少年吸菸的研究表明: (a)友誼網絡對菸草價格變化的反應放大了價格變化對吸菸的預期影響; (b)高中取消種族隔離降低了總體吸菸率; (c)吸菸者之間的同伴效應互補性明顯高於非吸菸者。(d)針對個人吸菸選擇的小規模政策的溢出效應大致是這些政策規模的兩倍。


澳大利亞新型冠狀病毒肺炎

流行引起的社區情緒動態研究


原文標題:
Examination of community sentiment dynamics due to covid-19 pandemic: a case study from Australia地址:

https://arxiv.org/abs/2006.12185

作者:

Jianlong Zhou,Shuiqiao Yang,Chun Xiao,Fang Chen

Abstract:The outbreak of the novel Coronavirus Disease 2019 (COVID-19) has caused unprecedented impacts to people’s daily life around the world. Various measures and policies such as lock-down and social-distancing are implemented by governments to combat the disease during the pandemic period. These measures and policies as well as virus itself may cause different mental health issues to people such as depression, anxiety, sadness, etc. In this paper, we exploit the massive text data posted by Twitter users to analyse the sentiment dynamics of people living in the state of New South Wales (NSW) in Australia during the pandemic period. Different from the existing work that mostly focuses the country-level and static sentiment analysis, we analyse the sentiment dynamics at the fine-grained local government areas (LGAs). Based on the analysis of around 94 million tweets that posted by around 183 thousand users located at different LGAs in NSW in five months, we found that people in NSW showed an overall positive sentimental polarity and the COVID-19 pandemic decreased the overall positive sentimental polarity during the pandemic period. The fine-grained analysis of sentiment in LGAs found that despite the dominant positive sentiment most of days during the study period, some LGAs experienced significant sentiment changes from positive to negative. This study also analysed the sentimental dynamics delivered by the hot topics in Twitter such as government policies (e.g. the Australia’s JobKeeper program, lock-down, social-distancing) as well as the focused social events (e.g. the Ruby Princess Cruise). The results showed that the policies and events did affect people’s overall sentiment, and they affected people’s overall sentiment differently at different stages.

摘要:2019年新型冠狀病毒病的爆發對世界各地人們的日常生活造成了前所未有的影響。新型冠狀病毒肺炎病毒感染是一種傳染病。各國政府實施了各種措施和政策,如封鎖和社會疏遠,以在大流行期間防治該疾病。這些措施和政策以及病毒本身都可能對人們造成不同的心理健康問題,如抑鬱、焦慮、悲傷等。在這篇論文中,我們利用 Twitter 用戶發布的大量文本數據來分析澳大利亞新南威爾斯州(NSW)流感大流行期間人們的情緒動態。不同於現有的主要集中在國家層面和靜態情緒分析的工作,我們分析情緒動態在細粒度的地方政府領域(lga)。根據對新南威爾斯州不同地區的18.3萬用戶在5個月內發布的大約9400萬條推文的分析,我們發現新南威爾斯州的人們表現出了一種總體上積極的情感極性,新型冠狀病毒肺炎流行病在流行期間減少了總體上積極的情感極性。對 LGAs 中情緒的細緻分析發現,儘管在研究期間的大多數日子裡,積極情緒占主導地位,但一些 LGAs 經歷了從積極到消極的重大情緒變化。這項研究還分析了 Twitter 上熱門話題所傳遞的情感動態,比如政府政策(比如澳大利亞的「就業守護者」計劃、封鎖、社會疏遠)以及重點社會事件(比如「紅寶石公主郵輪」)。結果表明,政策和事件確實影響了人們的整體情緒,並且在不同的階段對人們的整體情緒有不同的影響。

原文標題:Estimating Properties of Social Networks via Random Walk considering Private Nodes地址:

https://arxiv.org/abs/2006.12196

作者:

Kazuki Nakajima,Kazuyuki Shudo

AbstractAccurately analyzing graph properties of social networks is a challenging task because of access limitations to the graph data. To address this challenge, several algorithms to obtain unbiased estimates of properties from few samples via a random walk have been studied. However, existing algorithms do not consider private nodes who hide their neighbors in real social networks, leading to some practical problems. Here we design random walk-based algorithms to accurately estimate properties without any problems caused by private nodes. First, we design a random walk-based sampling algorithm that comprises the neighbor selection to obtain samples having the Markov property and the calculation of weights for each sample to correct the sampling bias. Further, for two graph property estimators, we propose the weighting methods to reduce not only the sampling bias but also estimation errors due to private nodes. The proposed algorithms improve the estimation accuracy of the existing algorithms by up to 92.6% on real-world datasets

摘要:準確地分析社會網絡的圖形屬性是一個具有挑戰性的任務,因爲對圖形數據的訪問受到限制。爲了應對這一挑戰,人們研究了幾種通過隨機遊動從少數樣本中獲得無偏估計的算法。然而,現有的算法沒有考慮到隱藏在真實社會網絡中鄰居的私有節點,這就導致了一些實際問題。在這裡,我們設計了基於隨機漫步的算法,以準確地估計屬性沒有任何問題所造成的私有節點。首先,我們設計了一個基於隨機遊走的抽樣算法,包括鄰居選擇,以獲得具有馬爾可夫性的樣本,並計算每個樣本的權重來校正抽樣偏差。進一步,對於兩個圖的性質估計,我們提出了加權方法,以減少抽樣偏差和估計誤差由於私有節點。在真實數據集上,該算法的估計精度提高了92.6%。


亞洲國家的風險溝通: 

新型冠狀病毒肺炎在 Twitter 上的演講


原文標題:Risk Communication in Asian Countries: COVID-19 Discourse on Twitter地址:

https://arxiv.org/abs/2006.12218

作者:

Sungkyu Park,Sungwon Han,Jeongwook Kim,Mir Majid Molaie,Hoang Dieu Vu,Karandeep Singh,Jiyoung Han,Wonjae Lee,Meeyoung Cha

Abstract:COVID-19 has become one of the most widely talked about topics on social media. This research characterizes risk communication patterns by analyzing the public discourse on the novel coronavirus from four Asian countries: South Korea, Iran, Vietnam, and India, which suffered the outbreak to different degrees. The temporal analysis shows that the official epidemic phases issued by governments do not match well with the online attention on COVID-19. This finding calls for a need to analyze the public discourse by new measures, such as topical dynamics. Here, we propose an automatic method to detect topical phase transitions and compare similarities in major topics across these countries over time. We examine the time lag difference between social media attention and confirmed patient counts. For dynamics, we find an inverse relationship between the tweet count and topical diversity.

摘要:新型冠狀病毒肺炎已經成爲社交媒體上被廣泛討論的話題之一。這項研究通過分析來自四個亞洲國家: 韓國、伊朗、越南和印度的關於新型冠狀病毒的公共話語來描述風險傳播模式。時間分析表明,政府發布的官方流行病階段並不能很好地匹配網上對新型冠狀病毒肺炎的關注。這個發現需要通過新的方法來分析公共話語,比如時事動態。在這裡,我們提出了一種自動檢測局部相變的方法,並隨著時間的推移比較這些國家的主要議題的相似性。我們調查了社交媒體關注度和確診患者數量之間的時滯差異。在動態方面,我們發現了推文數量和主題多樣性之間的反比關係。

原文標題:When social influence promotes the wisdom of crowds地址:

https://arxiv.org/abs/2006.12471

作者:

Abdullah Almaatouq,M. Amin Rahimian,Abdulla Alhajri

Abstract:Questions regarding whether, and if so, under what conditions, groups exhibit ”crowd wisdom” have spurred numerous studies in many disciplines, including management and organizational science, psychology, sociology, complex systems, and computer science. Substantial effort in previous research on these questions has focused on investigating the role of social influence in promoting the wisdom of the crowd or, conversely, leading the crowd astray. Specifically, many previous studies have sought to infer the importance of social influence network attributes (such as influence centralization) to explain the accuracy of collective estimates. In this paper, we argue that this approach is limited and can lead to inconsistent conclusions. Based on our theoretical analysis, numerical simulation, and reanalysis of four previously published experiments (which included a total of 4,002 human participants, organized in 131 independent groups), we demonstrate that the wisdom of crowds in estimation tasks depends on the interaction between the following two factors: (i) centralization of the social influence network, and (ii) the features of the estimation context—i.e., the distribution of the initial (pre-influence) estimates. Specifically, we find that centralized influence is desirable in situations where a crowd is predisposed to overestimation bias and/or have a high likelihood of committing egregious errors. By adopting a framework that integrates both the structure of social influence and the estimation context, we bring the previously conflicting results under one theoretical framework and clarify the effects of influence centralization on the quality of crowd wisdom.

摘要:關於是否,如果是,在什麼條件下,羣體表現出「羣體智慧」的問題已經激發了許多學科的大量研究,包括管理和組織科學、心理學、社會學、複雜系統和計算機科學。以前對這些問題的大量研究都集中在調查社會影響力在提升羣體智慧中的作用,或者相反,引導羣體誤入歧途。具體來說,許多以前的研究都試圖推斷社會影響網絡屬性(如影響集中)的重要性來解釋集體估計的準確性。在本文中,我們認爲這種方法是有限的,並可能導致不一致的結論。基於我們的理論分析、數值模擬以及對以前發表的四個實驗的重新分析(包括總共4002個人參與者,組織在131個獨立的小組中) ,我們證明了羣體在評估任務中的智慧取決於以下兩個因素之間的相互作用: (i)社會影響網絡的集中性,和(ii)評估環境的特徵——即初始(預影響)評估的分布。具體來說,我們發現,在人羣傾向於過高估計偏差和 / 或犯下嚴重錯誤的可能性很高的情況下,集中影響是可取的。通過採用一個整合了社會影響力結構和評價語境的框架,我們把以前相互衝突的結果放在一個理論框架下,闡明了影響力集中對羣體智慧質量的影響。


實驗耦合 logistic 映射中

的分岔和滯後現象

原文標題:Observation of bifurcations and hysteresis in experimentally coupled logistic maps地址:

https://arxiv.org/abs/2006.11378

作者:

Caracé Gutiérrez,Cecilia Cabeza,Nicolás Rubido

Abstract:Initially, the logistic map became popular as a simplified model for population growth. In spite of its apparent simplicity, as the population growth-rate is increased the map exhibits a broad range of dynamics, which include bifurcation cascades going from periodic to chaotic solutions. Studying coupled maps allows to identify other qualitative changes in the collective dynamics, such as pattern formations or hysteresis. Particularly, hysteresis is the appearance of different attracting sets, a set when the control parameter is increased and another set when it is decreased — a multi-stable region. In this work, we present an experimental study on the bifurcations and hysteresis of nearly identical, coupled, logistic maps. Our logistic maps are an electronic system that has a discrete-time evolution with a high signal-to-noise ratio (∼106), resulting in simple, precise, and reliable experimental manipulations, which include the design of a modifiable diffusive coupling configuration circuit. We find that the characterisations of the isolated and coupled logistic-maps’ dynamics agrees excellently with the theoretical and numerical predictions (such as the critical bifurcation points and Feigenbaum’s bifurcation velocity). Here, we report multi-stable regions appearing robustly across configurations, even though our configurations had parameter mismatch (which we measure directly from the components of the circuit and also infer from the resultant dynamics for each map) and were unavoidably affected by electronic noise.

摘要:最初,邏輯地圖作爲人口增長的簡化模型而流行起來。儘管它看起來簡單,但是隨著人口增長率的增加,這個映射展示了一個廣泛的動力學範圍,其中包括從周期解到混沌解的分叉級聯。研究耦合映射允許識別集體動力學的其他定性變化,如圖案形成或滯後。特別地,滯後是指不同吸引集的出現,控制參數增加時出現的滯後現象,控制參數減少時出現的滯後現象——多穩定區域。在這項工作中,我們提出了一個實驗研究分岔和滯後的幾乎相同,耦合,邏輯斯諦映射。我們的邏輯地圖是一個電子系統,具有離散時間演變的高信噪比(∼106), 設計了一種可變擴散耦合結構電路,實現了簡單、精確、可靠的實驗操作。我們發現孤立和耦合 logistic 映射的動力學特徵與理論和數值預測(如臨界分岔點和 Feigenbaum 分岔速度)非常吻合。在這裡,我們報告了多穩定區域在配置上表現強勁,儘管我們的配置有參數不匹配(我們直接從電路的元件測量,並從每個映射的結果動力學推斷) ,並且不可避免地受到電子噪聲的影響。

原文標題:Identifying edges that facilitate the generation of extreme events in networked dynamical systems地址:

https://arxiv.org/abs/2006.11410

作者:

Timo Bröhl,Klaus Lehnertz

Abstract:The collective dynamics of complex networks of FitzHugh-Nagumo units exhibits rare and recurrent events of high amplitude (extreme events) that are preceded by so-called proto-events during which a certain fraction of the units become excited. Although it is well known that a sufficiently large fraction of excited units is required to turn a proto-event into an extreme event, it is not yet clear how the other units are being recruited into the final generation of an extreme event. Addressing this question and mimicking typical experimental situations, we investigate the centrality of edges in time-dependent interaction networks. We derived these networks from time series of the units’ dynamics employing a widely used bivariate analysis technique. Using our recently proposed edge centrality concepts together with an edge-based network decomposition technique, we observe that the recruitment is primarily facilitated by sets of certain edges that have no equivalent in the underlying topology. Our finding might aid to improve the understanding of generation of extreme events in natural networked dynamical systems.

摘要:Fitzhugh-nagumo 單元複雜網絡的集體動力學表現出罕見的高振幅反覆事件(極端事件) ,這些事件之前發生所謂的原始事件,在此期間某些單元被激發。雖然衆所周知,要把一個原始事件變成一個極端事件,需要一小部分激發單位的足夠大,但是其他單位是如何被招募到一個極端事件的最後一代中還不清楚。針對這個問題,模擬典型的實驗情況,我們研究了依賴時間的交互網絡中邊緣的中心性。我們利用廣泛使用的雙變量分析技術,從單位動態的時間序列中推導出這些網絡。使用我們最近提出的邊緣中心性概念和基於邊緣的網絡分解技術,我們觀察到招募主要是由某些邊的集合促成的,這些邊在底層拓撲中沒有等價物。我們的發現可能有助於提高對自然網絡動力系統中極端事件產生的理解。

原文標題:Functional differentiations in evolutionary reservoir computing networks地址:

http://arxiv.org/abs/2006.11507

作者:

Yutaka Yamaguti,Ichiro Tsuda

Abstract:We propose an extended reservoir computer that shows the functional differentiation of neurons. The reservoir computer is developed to enable changing of the internal reservoir using evolutionary dynamics, and we call it an evolutionary reservoir computer. To develop neuronal units to show specificity, depending on the input information, the internal dynamics should be controlled to produce contracting dynamics after expanding dynamics. Expanding dynamics magnifies the difference of input information, while contracting dynamics contributes to forming clusters of input information, thereby producing multiple attractors. The simultaneous appearance of both dynamics indicates the existence of chaos. In contrast, sequential appearance of these dynamics during finite time intervals may induce functional differentiations. In this paper, we show how specific neuronal units are yielded in the evolutionary reservoir computer.

摘要:我們提出了一個擴展的儲備計算機,顯示神經元的功能分化。油藏計算機是利用演化動力學來實現油藏內部變化的,我們稱之爲演化油藏計算機。爲了發展神經元單位以顯示特異性,根據輸入信息,控制內部動力學,在擴展動力學後產生收縮動力學。擴展的動力學放大了輸入信息的差異,而收縮的動力學有助於形成輸入信息的集羣,從而產生多個吸引子。這兩種動力學的同時出現表明混沌的存在。相反,在有限的時間間隔內,這些動力學的連續出現可能誘導功能分化。在這篇文章中,我們展示了特定的神經元單位是如何在進化儲備計算機中產生的。

原文標題:Opinion Maximization in Social Trust Networks地址:

https://arxiv.org/abs/2006.10961

作者:

Pinghua Xu,Wenbin Hu,Jia Wu,Weiwei Liu

Abstract:Social media sites are now becoming very important platforms for product promotion or marketing campaigns. Therefore, there is broad interest in determining ways to guide a site to react more positively to a product with a limited budget. However, the practical significance of the existing studies on this subject is limited for two reasons. First, most studies have investigated the issue in oversimplified networks in which several important network characteristics are ignored. Second, the opinions of individuals are modeled as bipartite states(e.g., support or not) in numerous studies, however, this setting is too strict for many real scenarios. In this study, we focus on social trust networks(STNs), which have the significant characteristics ignored in the previous studies. We generalized a famed continuous-valued opinion dynamics model for STNs, which is more consistent with real scenarios. We subsequently formalized two novel problems for solving the issue in STNs. Moreover, we developed two matrix-based methods for these two problems and experiments on real-world datasets to demonstrate the practical utility of our methods.

摘要:社交媒體網站現在正成爲產品推廣或營銷活動的重要平台。因此,有廣泛的興趣,確定如何指導網站反應更積極的產品與有限的預算。然而,由於兩個方面的原因,現有研究的現實意義有限。首先,大多數研究都是在過分簡化的網絡中進行研究,忽略了一些重要的網絡特徵。其次,在許多研究中,個人的意見被建模爲兩部分的狀態(例如,支持與否) ,然而,這種設置對於許多真實的場景來說過於嚴格。本研究以社會信任網絡爲研究對象,以往的研究忽略了其重要特徵。我們推廣了一個著名的連續值觀點動力學模型,該模型更符合實際場景。隨後,我們將兩個新問題正式化,以解決在 stn 中的問題。此外,我們還針對這兩個問題開發了兩種基於矩陣的方法,並在實際數據集上進行了實驗,以證明我們的方法的實用性。

原文標題:SenWave: Monitoring the Global Sentiments under the COVID-19 Pandemic地址:

https://arxiv.org/abs/2006.10842

作者:

Qiang Yang,Hind Alamro,Somayah Albaradei,Adil Salhi,Xiaoting Lv,Changsheng Ma,Manal Alshehri,Inji Jaber,Faroug Tifratene,Wei Wang,Takashi Gojobori,Carlos M. Duarte,Xin Gao,Xiangliang Zhang

Abstract:Since the first alert launched by the World Health Organization (5 January, 2020), COVID-19 has been spreading out to over 180 countries and territories. As of June 18, 2020, in total, there are now over 8,400,000 cases and over 450,000 related deaths. This causes massive losses in the economy and jobs globally and confining about 58% of the global population. In this paper, we introduce SenWave, a novel sentimental analysis work using 105+ million collected tweets and Weibo messages to evaluate the global rise and falls of sentiments during the COVID-19 pandemic. To make a fine-grained analysis on the feeling when we face this global health crisis, we annotate 10K tweets in English and 10K tweets in Arabic in 10 categories, including optimistic, thankful, empathetic, pessimistic, anxious, sad, annoyed, denial, official report, and joking. We then utilize an integrated transformer framework, called simpletransformer, to conduct multi-label sentimental classification by fine-tuning the pre-trained language model on the labeled data. Meanwhile, in order for a more complete analysis, we also translate the annotated English tweets into different languages (Spanish, Italian, and French) to generated training data for building sentiment analysis models for these languages. SenWave thus reveals the sentiment of global conversation in six different languages on COVID-19 (covering English, Spanish, French, Italian, Arabic and Chinese), followed the spread of the epidemic. The conversation showed a remarkably similar pattern of rapid rise and slow decline over time across all nations, as well as on special topics like the herd immunity strategies, to which the global conversation reacts strongly negatively. Overall, SenWave shows that optimistic and positive sentiments increased over time, foretelling a desire to seek, together, a reset for an improved COVID-19 world.

摘要:自從世界衛生組織發布第一個預警(2020年1月5日)以來,新型冠狀病毒肺炎已經向180多個國家和地區傳播。截至2020年6月18日,總共有超過8,400,000個病例和超過450,000個相關死亡。這導致全球經濟和就業機會大量減少,限制了全球約58% 的人口。在本文中,我們介紹 SenWave,一個新穎的情感分析工作,使用收集的1.05億條推特和微博信息來評估全球在新型冠狀病毒肺炎流感大流行期間情感的興衰。爲了對我們面對這場全球健康危機時的感受進行細緻的分析,我們將10K 條推文用英語注釋,10K 條推文用阿拉伯語注釋,分爲10個類別,包括樂觀、感恩、同情、悲觀、焦慮、悲傷、煩惱、否認、官方報告和開玩笑。然後,我們利用一個集成的變換器框架,稱爲簡單變換器,進行多標籤情感分類,通過微調前訓練語言模型的標記數據。與此同時,爲了進行更全面的分析,我們還將帶注釋的英文 tweets 翻譯成不同的語言(西班牙語、義大利語和法語) ,以生成用於構建這些語言的情感分析模型的培訓數據。因此,SenWave 揭示了流行病傳播之後,全球對話在新型冠狀病毒肺炎上以6種不同語言(包括英語、西班牙語、法語、義大利語、阿拉伯語和中文)進行的情緒。隨著時間的推移,在所有國家,以及在諸如羣體免疫策略這樣的特殊話題上,全球對話都會產生強烈的負面反應,這種對話顯示出一種非常相似的快速上升和緩慢下降的模式。總的來說,SenWave 顯示樂觀和積極的情緒隨著時間的推移而增長,預示著一種共同尋求改善新型冠狀病毒肺炎世界的願望。

原文標題:HPRA: Hyperedge Prediction using Resource Allocation地址:

https://arxiv.org/abs/2006.10842

作者:

Tarun Kumar,K Darwin,Srinivasan Parthasarathy,Balaraman Ravindran

Abstract:Many real-world systems involve higher-order interactions and thus demand complex models such as hypergraphs. For instance, a research article could have multiple collaborating authors, and therefore the co-authorship network is best represented as a hypergraph. In this work, we focus on the problem of hyperedge prediction. This problem has immense applications in multiple domains, such as predicting new collaborations in social networks, discovering new chemical reactions in metabolic networks, etc. Despite having significant importance, the problem of hyperedge prediction hasn’t received adequate attention, mainly because of its inherent complexity. In a graph withn nodes the number of potential edges is O(n2), whereas in a hypergraph, the number of potential hyperedges is O(2n). To avoid searching through such a huge space, current methods restrain the original problem in the following two ways. One class of algorithms assume the hypergraphs to be k-uniform. However, many real-world systems are not confined only to have interactions involving k components. Thus, these algorithms are not suitable for many real-world applications. The second class of algorithms requires a candidate set of hyperedges from which the potential hyperedges are chosen. In the absence of domain knowledge, the candidate set can have O(2n) possible hyperedges, which makes this problem intractable. We propose HPRA – Hyperedge Prediction using Resource Allocation, the first of its kind algorithm, which overcomes these issues and predicts hyperedges of any cardinality without using any candidate hyperedge set. HPRA is a similarity-based method working on the principles of the resource allocation process. In addition to recovering missing hyperedges, we demonstrate that HPRA can predict future hyperedges in a wide range of hypergraphs.

摘要:許多現實世界的系統涉及到高階的相互作用,因此需要複雜的模型,如超圖。例如,一篇研究論文可能有多個合作作者,因此合作作者網絡最好用超圖來表示。本文主要研究超邊界預測問題。這個問題在多個領域有著廣泛的應用,例如在社交網絡中預測新的合作,在新陳代謝網絡中發現新的化學反應等。超邊緣預測問題雖然具有重要的意義,但由於其固有的複雜性,一直沒有得到足夠的重視。在一個帶有n 節點的位勢邊的數目是O(n2), 然而在超圖中,勢超邊的個數是O(2n). 爲了避免在這樣一個巨大的空間中進行搜索,現有的方法主要從以下兩個方面來抑制原問題。一類算法假設超圖是k- 統一。然而,許多現實世界的系統並不只局限於包括k 組件。因此,這些算法不適用於許多現實世界的應用。第二類算法需要一組候選超邊,從中選擇潛在的超邊。在沒有領域知識的情況下,候選集可以具有O(2n) 可能是超邊,這使得這個問題很棘手。本文提出了一種基於資源分配的 HPRA-超邊預測算法,該算法克服了這些問題,不需要使用任何候選超邊集就可以預測任意基數的超邊。Hpra 是一種基於相似性的方法,它遵循資源分配過程的原則。除了恢復丟失的超邊外,我們證明了 HPRA 能夠在廣泛的超圖中預測未來的超邊。

原文標題:Measuring Adolescents’ Well-being: Correspondence of Naive Digital Traces to Survey Data地址:

https://arxiv.org/abs/2006.11176

作者:

Elizaveta Sivak,Ivan Smirnov

Abstract:Digital traces are often used as a substitute for survey data. However, it is unclear whether and how digital traces actually correspond to the survey-based traits they purport to measure. This paper examines correlations between self-reports and digital trace proxies of depression, anxiety, mood, social integration and sleep among high school students. The study is based on a small but rich multilayer data set (N = 144). The data set contains mood and sleep measures, assessed daily over a 4-month period, along with survey measures at two points in time and information about online activity from VK, the most popular social networking site in Russia. Our analysis indicates that 1) the sentiments expressed in social media posts are correlated with depression; namely, adolescents with more severe symptoms of depression write more negative posts, 2) late-night posting indicates less sleep and poorer sleep quality, and 3) students who were nominated less often as somebody’s friend in the survey have fewer friends on VK and their posts receive fewer “likes.” However, these correlations are generally weak. These results demonstrate that digital traces can serve as useful supplements to, rather than substitutes for, survey data in studies on adolescents’ well-being. These estimates of correlations between survey and digital trace data could provide useful guidelines for future research on the topic.

摘要:數字痕跡經常被用作調查數據的替代品。然而,目前還不清楚數字痕跡是否以及如何與他們聲稱要測量的基於調查的特徵相對應。本文研究了高中生自我報告與抑鬱、焦慮、情緒、社會整合和睡眠的數字痕跡代理之間的相關性。這項研究是基於一個小而豐富的多層數據集(n = 144)。這些數據包括情緒和睡眠測量數據,在4個月的時間裡每天進行評估,同時還包括兩個時間點的調查測量數據,以及俄羅斯最受歡迎的社交網站 VK 提供的有關在線活動的信息。我們的分析表明: 1)社交媒體帖子中表達的情緒與抑鬱症有關; 也就是說,抑鬱症症狀更嚴重的青少年寫的負面帖子更多; 2)深夜發帖意味著睡眠更少、睡眠質量更差; 3)在調查中被提名爲朋友的學生在 VK 上的朋友更少,他們的帖子得到的「贊」也更少 然而,這些相關性普遍較弱。這些結果表明,在青少年幸福研究中,數字痕跡可以作爲調查數據的有用補充,而不是替代。這些關於調查和數字痕跡數據之間相關性的估計可以爲今後關於這一主題的研究提供有用的指導。

原文標題:Rumor source detection with multiple observations under adaptive diffusions地址:

https://arxiv.org/abs/2006.11176

作者:

Miklos Z. Racz,Jacob Richey

Abstract:Recent work, motivated by anonymous messaging platforms, has introduced adaptive diffusion protocols which can obfuscate the source of a rumor: a “snapshot adversary” with access to the subgraph of “infected” nodes can do no better than randomly guessing the entity of the source node. What happens if the adversary has access to multiple independent snapshots? We study this question when the underlying graph is the infinited-regular tree. We show that (1) a weak form of source obfuscation is still possible in the case of two independent snapshots, but (2) already with three observations there is a simple algorithm that finds the rumor source with constant probability, regardless of the adaptive diffusion protocol. We also characterize the tradeoff between local spreading and source obfuscation for adaptive diffusion protocols (under a single snapshot). These results raise questions about the robustness of anonymity guarantees when spreading information in social networks.

摘要:最近,在匿名消息傳遞平台的推動下,引入了自適應擴散協議,這種協議可以模糊謠言的來源: 有權訪問「被感染」節點子圖的「對手快照」只能隨機猜測源節點的實體。如果對手可以訪問多個獨立的快照會發生什麼?當底圖是無窮大時,我們研究這個問題d- 普通樹。我們證明: (1)在兩個獨立的快照情況下,仍然可能存在一種弱形式的源混淆,但是(2)已經有了三個觀察值,有一個簡單的算法,不管自適應擴散協議如何,都可以找到具有常數概率的謠言源。我們還刻畫了自適應擴散協議在本地擴散和源模糊之間的權衡(在單個快照下)。這些結果提出了關於在社會網絡中傳播信息時匿名保證的穩健性的問題。


心理物理學: 

兩個耦合的正方形脈衝神經元

在臨界狀態下具有巨大的動態範圍

原文標題:Physics of Psychophysics: two coupled square lattices of spiking neurons have huge dynamic range at criticality地址:

https://arxiv.org/abs/2006.11254

作者:

Emilio F. Galera,Osame Kinouchi

Abstract:Psychophysics try to relate physical input magnitudes to psychological or neural correlates. Microscopic models to account for macroscopic psychophysical laws, in the sense of statistical physics, are an almost unexplored area. Here we examine a sensory epithelium composed of two connected square lattices of stochastic integrate-and-fire cells. With one square lattice we obtain a Stevens’s lawρ∝hm with Stevens’s exponent m=0.254 and a sigmoidal saturation, where ρ is the neuronal network activity and h is the input intensity (external field). We relate Stevens’s power law exponent with the field critical exponent as m=1/δh=β/σ. We also show that this system pertains to the Directed Percolation (DP) universality class (or perhaps the Compact-DP class). With stacked two layers of square lattices, and a fraction of connectivity between the first and second layer, we obtain at the output layer ρ2∝hm2, with m2=0.08≈m2, which corresponds to a huge dynamic range. This enhancement of the dynamic range only occurs when the layers are close to their critical point.

摘要:心理物理學試圖將物理輸入量與心理或神經相關聯。用微觀模型來解釋宏觀的心理物理定律,在統計物理學的意義上,是一個幾乎未被探索的領域。在這裡,我們檢查一個感覺上皮組成的兩個連接的方格隨機積分和火細胞。對於一個正方形點陣,我們得到了一個斯蒂文斯定律ρ∝hm 史蒂文斯的指數m=0.254 和相似的飽和度,其中ρ 是是神經元網絡活動,h 是 輸入強度 ,我們將斯蒂文斯的冪律指數與場臨界指數關係如下:m=1/δh=β/σ.我們還證明了該系統屬於定向 Percolation (DP)普適性類(或者可能屬於 compact-DP 類)。通過疊加兩層正方形晶格,以及第一層和第二層之間連通性的一小部分,我們可以在輸出層獲得ρ2∝hm2, m2=0.08≈m2,相當於一個巨大的動態範圍。這種動態範圍的增強只發生在層接近其臨界點的時候。

原文標題:UK COVID-19 Lockdown: What are the impacts on air pollution地址:

https://arxiv.org/abs/2006.10785

作者:

J. E. Higham,M. A. Green,C. Acosta Ramirez

Abstract:A country-wide `lock-down’ imposed on the 23red March 2020 in the UK had a significant impact on the UK’s anthropogenic movements. The closure of work-places and restrictions imposed on visiting friends and family has radically reduced the amount of traffic on the roads. In this short communication, we use data from UK air-quality sensors to quantify air pollution trends pre- and post-lock-down. While we detect large falls in nitrogen dioxide at levels not seen over the last decade, trends in other pollutants were mixed especially when compared to historical data. It suggests that the implication that lock-down was beneficial for the environment was not so obvious.

摘要:2020年3月23日,英國實施了全國範圍的「封鎖」 ,對英國的人爲活動產生了重大影響。工作場所的關閉以及對探望朋友和家人的限制大大減少了道路上的交通量。在這個簡短的交流中,我們使用來自英國空氣品質傳感器的數據來量化封鎖前後的空氣汙染趨勢。雖然我們檢測到二氧化氮的水平大幅下降,但是其他汙染物的趨勢卻好壞參半,尤其是與歷史數據相比。這表明,封鎖有利於環境的含義並不是那麼明顯。

原文標題:Geometry, Inference, Complexity, and Democracy地址:

https://arxiv.org/abs/2006.10879

作者:

Jordan S. Ellenberg

Abstract:Decisions about how the population of the United States should be divided into legislative districts have powerful and not fully understood effects on the outcomes of elections. The problem of understanding what we might mean by “fair districting” intertwines mathematical, political, and legal reasoning; but only in recent years has the academic mathematical community gotten directly involved in the process. I’ll report on recent progress in this area, how newly developed mathematical tools have affected real political decisions, and what remains to be done. This survey represents the content of a lecture presented by the author in the Current Events Bulletin session of the Joint Mathematics Meetings in January 2020.

摘要:關於如何將美國人口劃分爲立法區的決定對選舉結果產生了強大而又未被充分理解的影響。理解我們所說的「公平分區」是什麼意思的問題將數學、政治和法律推理聯繫在一起; 但是直到最近幾年,學術數學界才直接參與到這個過程中來。我將報告這一領域的最新進展,新開發的數學工具如何影響真正的政治決策,以及還需要做什麼。本調查是作者在2020年1月數學聯席會議的時事簡報會上發表的一次演講的內容。


使用概率細胞自動機研究

計算模型新型冠狀病毒肺炎流行病


原文標題:Computational model on COVID-19 Pandemic using Probabilistic Cellular Automata地址:

https://arxiv.org/abs/2006.11270

作者:

Sayantari Ghosh,Saumik Bhattacharya

Abstract:Coronavirus disease (COVID-19) which is caused by SARS-COV2 has become a pandemic. This disease is highly infectious and potentially fatal, causing a global public health concern. To contain the spread of COVID-19, governments are adopting nationwide interventions, like lockdown, containment and quarantine, restrictions on travel, cancelling social events and extensive testing. To understand the effects of these measures on the control of the epidemic in a data-driven manner, we propose a probabilistic cellular automata (PCA) based modified SEIQR model. The transitions associated with the model is driven by data available on chronology, symptoms, pathogenesis and transmissivity of the virus. By arguing that the lattice-based model captures the features of the dynamics along with the existing fluctuations, we perform rigorous computational analyses of the model to take into account of the spatial dynamics of social distancing measures imposed on the people. Considering the probabilistic behavioural aspects associated with mitigation strategies, we study the model considering factors like population density and testing efficiency. Using the model, we focus on the variability of epidemic dynamics data for different countries and point out the reasons behind these contrasting observations. To the best of our knowledge, this is the first attempt to model COVID-19 spread using PCA that gives us both spatial and temporal variations of the infection spread with the insight about the contributions of different infection parameters.

摘要:由 SARS-COV2引起的冠狀病毒病(新型冠狀病毒肺炎)已經成爲一種流行病。這種疾病具有高度傳染性,可能致命,引起全球公共衛生關注。爲了遏制新型冠狀病毒肺炎的蔓延,各國政府正在採取全國性的干預措施,如封鎖、隔離和隔離、限制旅行、取消社會活動和廣泛的檢測。爲了以數據驅動的方式理解這些措施對流行病控制的影響,我們提出了一種基於概率元胞自動機(PCA)的改進 SEIQR 模型。與該模型相關的轉變是由關於病毒的年代學、症狀、發病機制和傳播率的數據驅動的。通過論證基于格子的模型捕獲了動力學的特徵以及存在的波動,我們對模型進行了嚴格的計算分析,以考慮強加在人們身上的社會距離措施的空間動力學。考慮到與減災策略相關的概率行爲方面,我們研究了考慮種羣密度和測試效率等因素的模型。利用該模型,我們重點關注不同國家的流行病動態數據的可變性,並指出這些對比觀察背後的原因。據我們所知,這是第一次嘗試使用 PCA 模型來模擬新型冠狀病毒肺炎傳播,該模型通過洞察不同感染參數的作用,爲我們提供了感染傳播的時空變化。



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