3,343 research outputs found
Tomography Of Adaptive Multi-Agent Networks Under Limited Observation
No full textThis work studies the problem of inferring from streaming data whether an agent is directly influenced by another agent over an adaptive network of interacting agents. Agent i influences agent j if they are connected, and if agent j uses the information from agent i to update its inference. The solution of this inference task is challenging for at least two reasons. First, only the output of the learning algorithm is available to the external observer and not the raw data. Second, only observations from a fraction of the network agents is available, with the total number of agents itself being also unknown. This work establishes, under reasonable conditions, that consistent tomography is possible, namely, that it is possible to reconstruct the interaction profile of the observable portion of the network, with negligible error as the network size increases. We characterize the decaying behavior of the error with the network size, and provide a set of numerical experiments to illustrate the results.AS
Tomography of Large Adaptive Networks under the Dense Latent Regime
No full textThis work examines the problem of graph learning over a diffusion network when measurements can only be gathered from a limited fraction of agents (latent regime). Under this selling, most works in the literature rely on a degree of sparsity to provide guarantees of consistent graph recovery. This work moves away from this condition and shows that, even under dense connectivity, the Granger estimator ensures an identifiability gap that enables the discrimination between connected and disconnected nodes within the observable subnetwork
EKO-SPIRITUALITAS DALAM PEMIKIRAN SAYED HUSEIN NASHR
No full textThe environmental crisis in the modern era is currently a very serious issue. Environmental crises, such as deforestation, extinction of wildlife, plastic waste pollution, environmentally unfriendly industrialization activities, illegal logging and forest fires are prime examples. Various solutions have been offered from various perspectives, but this research discusses and offers solutions from the perspective of Islamic teachings by its originator, namely Sayed Husein Nashr. The aim of this research is to find out the answer to Islamic teachings to the challenges of the environmental crisis, to know the responsibility of humans as balancers of nature, and to understand how important education and spiritual awareness are in successfully preserving a sustainable environment. This research uses a qualitative method with a content analysis approach. Sayed Husein Nashr from an Islamic perspective stated that a more fundamental spiritual crisis is a manifestation of the environmental crisis we are currently facing. Holistic education and increasing spiritual awareness can be a solution to this problem.Krisis lingkungan pada era modern saat ini menjadi isu sangat serius. Krisis lingkungan, seperti penggundulan hutan, punahnya satwa liar, pencemaran sampah plastik, kegiatan industrialisasi yang tidak ramah lingkungan, penebangan illegal, dan kebakaran hutan menjadi contoh utama. Berbagai tawaran solusi dari berbagai perspektif juga telah diutarakan, akan tetapi penelitian ini membahas dan memberi tawaran solusi dari perspektif ajaran Islam oleh pencetusnya yakni Sayed Husein Nashr. Tujuan penelitian ini adalah untuk mengetahui jawaban ajaran Islam atas tantangan krisis lingkungan, mengetahui tanggung jawab manusia sebagai penyeimbang alam, dan memahami betapa pentingnya pendidikan dan kesadaran spiritual dalam suksesnya melestarikan lingkungan yang berkelanjutan. Penelitian ini menggunakan metode kualitatif dengan pendekatan analisis isi. Sayed Husein Nashr dengan kacamata Islam menyatakan, bahwa krisis spiritual yang lebih mendasar adalah manifestasi dari krisis lingkungan yang kita hadapi saat ini. Pendidikan yang holistik dan peningkatan kesadaran spiritual dapat menjadi solusi atas masalah tersebut
Graph Learning with Partial Observations: Role of Degree Concentration
No full textIn this work we consider the problem of learning an Erdos-Renyi graph over a diffusion network when: i) data from only a limited subset of nodes are available (partial observation); ii) and the inferential goal is to discover the graph of interconnections linking the accessible nodes (local structure learning). We propose three matrix estimators, namely, the Granger, the onelag correlation, and the residual estimators, which, when followed by a universal clustering algorithm, are shown to retrieve the true subgraph in the limit of large network sizes. Remarkably, it is seen that a fundamental role is played by the uniform concentration of node degrees, rather than by sparsity
Consistent Tomography over Diffusion Networks under the Low-Observability Regime
No full textThis work considers a diffusion network responding to streaming data, and studies the problem of identifying the topology of a subnetwork of observable agents by tracking their output measurements. Topology inference from indirect and/or incomplete datasets (network tomography) is in general an ill-posed problem. Under an appropriate Erdos-Renyi random graph model for the unobserved part, the problem of network tomography is well-posed in the thermodynamic limit: when the number of network agents grows to infinity, any arbitrary subnetwork topology associated with the observed agents can be recovered with high probability.AS
DIVIDE-AND-CONQUER TOMOGRAPHY FOR LARGE-SCALE NETWORKS
No full textThis work considers the problem of reconstructing the topology of a network of interacting agents via observations of the state-evolution of the agents. Observations from only a subset of the nodes are collected, and the information is used to infer their local connectivity (local tomography). Recent results establish that, under suitable conditions on the network model, local tomography is achievable with high probability as the network size scales to infinity [1, 2]. Motivated by these results, we explore the possibility of reconstructing a larger network via repeated application of the local tomography algorithm to smaller network portions. A divide-and-conquer strategy is developed and tested numerically on some illustrative examples
Exponential Collapse of Social Beliefs over Weakly-connected Heterogeneous Networks
No full textWe consider a distributed social learning problem where a network of agents is interested in selecting one among a finite number of hypotheses. The data collected by the agents might be heterogeneous, meaning that different sub-networks might observe data generated by different hypotheses. For example, some sub-networks might be receiving (or even intentionally generating) data from a fake hypothesis and will bias the rest of the network via social influence. This work focuses on a two-step diffusion algorithm where each agent: i) first updates individually its belief function using its private data; ii) then computes a new belief function by exponentiating a linear combination of the log-beliefs of its neighbors. We obtain analytical formulas that reveal how the agents' detection capability and the network topology interplay to influence the asymptotic beliefs of the agents. Some interesting behaviors arise, such as the "mind-control" effect or the "truth-is-somewhere-in-between" effect
السيد مهدي القزويني الكبير (1222-1300هـــ/ 1807-1883م) (دراسة تاريخية) Al-Sayed The Great Mahdi al-Qazwini (1222-1300 AH / 1807-1883 AD) (Historical Study)
No full textThe Sayed Mahdi Al-Qazwini one of the most famous scientists of his time, and with dignity, and the effects of the Eternal, was born in Najaf in (1222 AH / 1807 AD), and he grew up loving grace and virtue, was a world inclusively, from the eyes of scholars and fundamentalists and Sheikh writers and speakers and face of the faces of writers and authors, he was a fair and honest and descant, maintain, with good ethics, solemn, and was his home in Najaf compound virtuous and writers and lectures, and the poetry was said in his house, and his Picked benefits and, prestige topped, and Majesty sarong, and tenderness parading of his words, the origins and genesis of his fathers and him they stayed in a country of science and Immigration (( Najaf )
Revisiting correlation-based functional connectivity and its relationship with structural connectivity
No full textPatterns of brain structural connectivity (SC) and functional connectivity (FC) are known to be related. In SC-FC comparisons, FC has classically been evaluated from correlations between functional time series, and more recently from partial correlations or their unnormalized version encoded in the precision matrix. The latter FC metrics yield more meaningful comparisons to SC because they capture 'direct' statistical dependencies, that is, discarding the effects of mediators, but their use has been limited because of estimation issues. With the rise of high-quality and large neuroimaging datasets, we revisit the relevance of different FC metrics in the context of SC-FC comparisons. Using data from 100 unrelated Human Connectome Project subjects, we first explore the amount of functional data required to reliably estimate various FC metrics. We find that precision-based FC yields a better match to SC than correlation-based FC when using 5 minutes of functional data or more. Finally, using a linear model linking SC and FC, we show that the SC-FC match can be used to further interrogate various aspects of brain structure and function such as the timescales of functional dynamics in different resting-state networks or the intensity of anatomical self-connections.MIPLABAS
- Marble slab with a Persian inscription of Jahāngīr dated AH 1027
No full textMarble slab with a Persian inscription of Jahāngīr dated AH 102
- …
