Latency Optimal Broadcasting in Noisy Wireless Mesh Networks

In this paper, we adopt a new noisy wireless network model introduced very recently by Censor-Hillel et al. in [ACM PODC 2017, CHHZ17]. More specifically, for a given noise parameter $p\in [0,1],$ any sender has a probability of $p$ of transmitting noise or any receiver of a single transmission in its neighborhood has a probability $p$ of receiving noise. In this paper, we first propose a new asymptotically latency-optimal approximation algorithm (under faultless model) that can complete single-message broadcasting task in $D+O(\log^2 n)$ time units/rounds in any WMN of size $n,$ and diameter $D$. We then show this diameter-linear broadcasting algorithm remains robust under the noisy wireless network model and also improves the currently best known result in CHHZ17 by a $\Theta(\log\log n)$ factor. In this paper, we also further extend our robust single-message broadcasting algorithm to $k$ multi-message broadcasting scenario and show it can broadcast $k$ messages in $O(D+k\log n+\log^2 n)$ time rounds. This new robust multi-message broadcasting scheme is not only asymptotically optimal but also answers affirmatively the problem left open in CHHZ17 on the existence of an algorithm that is robust to sender and receiver faults and can broadcast $k$ messages in $O(D+k\log n + polylog(n))$ time rounds.Comment: arXiv admin note: text overlap with arXiv:1705.07369 by other author

Impacts of Multi-Fiber Arrangement Removal on Global Textile and Cotton Trade

Textiles and apparel trade has been governed by the Multi-Fiber Arrangement (MFA) for three decades. Trade restrictions have generated substantial welfare losses and price wedges in exporting and importing countries through trade distortions. Beginning in 1995, textiles and apparel trade underwent fundamental changes. MFA quota will be removed by Jan 2005 according to World Trade Organization's Agreement on Textiles and Clothing (ATC). This study established an equilibrium displacement model to investigate the impact on textile and cotton sectors of different countries and country-groups of removing the MFA quota. The model specifies the basic linkages of textile and cotton markets in the United States, China and three other country-groups. With different parameter values for U.S. textile supply elasticity, assumptions about foreign cotton exporters' reaction and changes in the U.S. loan deficiency payment, alternative scenarios in the short run and long run are computed to predict changes in domestic and import demand for textiles and apparel, import demand for U.S. cotton, domestic and import price of textiles and apparel, U.S. cotton price and adjusted world cotton price. Generally, results indicated increased import demand for U.S. cotton, higher textiles/apparel export supply from China, decreased domestic demand for U.S. cotton, and lower U.S. domestic demand for textiles and apparel. However, both textile prices and cotton prices had positive or negative changes depending on different scenarios.Multi-fiber Arrangement, Textile, Apparel, Equilibrium Displacement Model, International Relations/Trade,

Spin-Cherenkov effect in a magnetic nanostrip with interfacial Dzyaloshinskii-Moriya interaction

Spin-Cherenkov effect enables strong excitations of spin waves (SWs) with nonlinear wave dispersions. The Dzyaloshinskii-Moriya interaction (DMI) results in anisotropy and nonreciprocity of SWs propagation. In this work, we study the effect of the interfacial DMI on SW Cherenkov excitations in permalloy thin-film strips within the framework of micromagnetism. By performing micromagnetic simulations, it is shown that coherent SWs are excited when the velocity of a moving magnetic source exceeds the propagation velocity of the SWs. Moreover, the threshold velocity of the moving magnetic source with finite DMI can be reduced compared to the case of zero DMI. It thereby provides a promising route towards efficient SW generation and propagation, with potential applications in spintronic and magnonic devices.Comment: 6 pages, 5 figures. To be published in Scientific Report

Robust semi-explicit model predictive control for hybrid automata

In this paper we propose an on-line design technique for the target control problem of hybrid automata. First, we compute on-line the shortest path, which has the minimum discrete cost, from an initial state to the given target set. Next, we derive a controller which successfully drives the system from the initial state to the target set while minimizing a cost function. The (robust) model predictive control (MPC) technique is used when the current state is not within a guard set, otherwise the (robust) mixed-integer predictive control (MIPC) technique is employed. An on-line, semi-explicit control algorithm is derived by combining the two techniques and applied on a high-speed and energy-saving control problem of the CPU processing