In this paper, we conduct mathematical and numerical analyses for COVID-19. To predict the trend of COVID-19, propose a time-dependent SIR model that tracks transmission recovering rate at time [Formula: see text]. Using data provided by China authority, show our one-day prediction errors are almost less than The turning point total number confirmed cases in predicted under model. analyze impact undetectable infections on spread disease, extend considering two types infected persons:...

Current methods of chemical vapour deposition (CVD) graphene on copper are complicated by multiple processing steps and high temperatures required in both preparing the inducing subsequent film growth. Here we demonstrate a plasma-enhanced CVD chemistry that enables entire process to take place single step, at reduced (<420 °C), matter minutes. Growth foils is found nucleate from arrays well-aligned domains, ensuing films possess sub-nanometre smoothness, excellent crystalline quality, low...

Two-dimensional lead (Pb) islands of varying heights have been grown on the Si(111)-(7 x 7) surface at low temperature. Individual are investigated concurrently with real-space and local-probe scanning tunneling microscopy spectroscopy. Quantum size effects, manifested in formation new electronic bound states, redistribution charge density, oscillatory relaxations island thickness found to be perfectly correlated each other.

Previously, we proposed a scheduling algorithm that is capable of providing rate guarantees for input-buffered crossbar switches. The based on decomposition result by Birkhoff (1945) and von Neumann (1953) doubly substochastic matrix. An input buffered switch uses such an called the Birkhoff-von in this paper. For switch, are uniformly good all non-uniform traffic, it does not require framing or internal speedup. Our objective paper to make more complete practical. We do so addressing three...

In this paper, we consider a queue with time varying capacity and identify the effective bandwidth of stationary departure process from such queue. Two important observations are made: (i) bandwidths for transient in general different, (ii) sometimes it is necessary to build up first order have large excursion process. The new result on applied intree networks capacities priority tandem queues. Algorithms approximating tail distributions lengths derived.

We develop a filtering theory for deterministic traffic regulation and service guarantees under the (min, +)-algebra. show that regulators generate f-upper constrained outputs can be implemented optimally by linear time-invariant filter with impulse response f/sub */ +)-algebra, where is subadditive closure defined in paper. Analogous to classical theory, there an associate calculus, including feedback, concatenation, "filter bank summation", performance bounds. The calculus also applicable...

Based on a decomposition result by Birkhoff (1946) and von Neumann (1953) for doubly substochastic matrix, in this paper we propose scheduling algorithm that is capable of providing service guarantees input-buffered crossbar switches. Our are uniformly good all non-uniform traffic, thus imply 100% throughput. The off-line computational complexity to identify the O(N/sup 4.5/) an N/spl times/N switch. Once identified, its on-line O(logN) memory 3/logN). Neither framing nor internal speedup...

We study the problem of wireless access to asynchronous transfer modes (ATMs). consider three classes ATM sources: constant bit rate (CBR), variable (VBR), and available (ABR). propose a polling scheme with nonpreemptive priority. Under such scheme, we derive sufficient conditions that all CBR sources satisfy their jitter constraints VBR delay constraints. The remaining bandwidth is used by ABR sources, for which adapt random proposed Chen Lee (1994). For this throughput-offer load...

Automatically recognizing personality based on historical action logs in online social networks is a promising method to infer person's behaviors, and it has received lot of attention lately as might lead the construction better personal recommendation system. However, very few previous works literature put their focus predicting from Chinese texts. As texts are much more difficult delimit than English texts, poses challenges In this paper, we attempt classify traits We collected dataset...

The matrix factorization (MF) technique has been widely adopted for solving the rating prediction problem in recommender systems. MF utilizes latent factor model to obtain static user preferences (user vectors) and item characteristics (item based on historical data. However, real world, are not but full of dynamics. Though there several previous works that addressed this time-varying issue preferences, it seems (to best our knowledge) none them specifically designed tracking concept drift...

The group testing approach, which achieves significant cost reduction over the individual has received a lot of interest lately for massive COVID-19. Many studies simply assume samples mixed in are independent. However, this assumption may not be reasonable contagious disease like Specifically, people within family tend to infect each other and thus likely positively correlated. By exploiting positive correlation, we make following two main contributions. One is provide rigorous proof that...

The concepts of linkage, building blocks, and problem decomposition have long existed in the genetic algorithm (GA) field guided development model-based GAs for decades. However, their definitions are usually vague, making it difficult to develop theoretical support. This paper provides an algorithm-independent definition describe concept linkage. With this definition, proves that any problems with a bounded degree linkage decomposable proper is possible via learning. way given also offers...

Motivated by the need of a simple and high performance switch architecture that scales up with speed fiber optics, we propose two-stage switching fabrics one-stage buffering. The first stage performs load balancing, while second is Birkhoff-von Neumann input-buffered for balanced traffic. Such called in this paper. on-line complexity O(1). It shown under mild technical condition on input traffic, achieves 100% throughput as an output-buffered both unicast multicast traffic fan-out splitting....

By extending the system theory under (min, +) algebra to time-varying setting, we solve problem of constrained traffic regulation and develop a calculus for dynamic service guarantees. For traffic-regulation with maximum tolerable delay d buffer size q, optimal regulator that generates output conforming subadditive envelope f minimizes number discarded packets is concatenation g-clipper g(t) = min[f(t+ d), (t)+q] maximal f-regulator. The bufferless device, which optimally drops as necessary...

Discrete-time queues are infinite dimensional switches in time.Ever since Shannon [22] published his paper on the memory requirements a telephone exchange, there have been tremendous efforts search for with minimum complexity.Constructing complexity has not received same amount of attention as relatively cheap to build via electronic memory.Recent advances optical technologies, however, spurred interest building complexity.In this paper, we develop mathematical theory constructing...

Traditionally, conflict resolution in an input-buffered switch is solved by finding a matching between inputs and outputs per time slot. To do this, not only needs to gather the information of virtual output queues at inputs, hut also uses gathered compute matching. As such, both communication overhead computation make it difficult scale. Recent works on two-stage architecture (6|, [7], [12], (8| showed that can be easily over space without overhead. However, main problem such packets might...

This paper is about load-balancing packets across multiple paths inside a switch, or network. It motivated by the recent interest in load-balanced switches. Load-balanced switches provide an appealing alternative to crossbars with centralized schedulers. A switch has no scheduler, particularly amenable optics, and - most relevant here -guarantees 100% throughput. uniform mesh used load-balance uniformly all 2-hop switch. In this we explore whether particular method of optimal sense that it...