Description: We propose a method to improve the performance of two entanglement-based continuous-variable quantum key distribution protocols using noiseless linear amplifiers. The two entanglement-based schemes consist of an entanglement distribution protocol with an untrusted source and an entanglement swapping protocol with an untrusted relay. Simulation results show that the noiseless linear amplifiers can improve the performance of these two protocols, in terms of maximal transmission distances, when we consider small amounts of entanglement, as typical in realistic setups.

Description: Author(s): Ying Chen, Ming Gong, Yu-Hong Lei, Ning Li, Jian Liang, Chuan Liu, Jin-Long Liu, Yong-Fu Liu, Yu-Bin Liu, Zhaofeng Liu, Jian-Ping Ma, Zhan-Lin Wang, and Jian-Bo Zhang (CLQCD Collaboration) In this paper, low-energy scattering of the ( D * D ¯ * ) ± meson system is studied within Lüscher’s finite-size formalism using N f = 2 twisted-mass gauge field configurations. With three different pion mass values, the s -wave threshold scattering parameters—namely the scattering length a 0 and the effective … [Phys. Rev. D 92, 054507] Published Mon Sep 21, 2015

Description: Atmosphere, Vol. 8, Pages 248: Numerical Study on the Generation and Transport of Spume Droplets in Wind over Breaking Waves Atmosphere doi: 10.3390/atmos8120248 Authors: Shuai Tang Zixuan Yang Caixi Liu Yu-Hong Dong Lian Shen Sea spray droplets play an important role in the momentum, heat and mass transfer in the marine atmospheric boundary layer. We have developed a new direct numerical simulation method to study the generation and transport mechanisms of spume droplets by wind blowing over breaking waves, with the wave breaking process taken into account explicitly. In this new computational framework, the air and water are simulated as a coherent system on fixed Eulerian grid with the density and viscosity varying with the fluid phase. The air-water interface is captured accurately using a coupled level-set and volume-of-fluid method. The trajectories of sea spray droplets are tracked using a Lagrangian particle-tracking method. The generation of droplets is captured by comparing the fluid particle velocity of water and the phase speed of the wave surface. From the simulation data, we obtain for the first time a detailed description of the instantaneous distribution of droplets at different stages of wave breaking. Furthermore, the time histories of the droplet number and its generation and disappearance rates are analyzed. Simulation cases with different parameters are performed to study the effects of wave age and wave steepness. The flow and droplet fields obtained from simulation provided a detailed physical picture of the problem of interest. It is found that plunging breakers generate more droplets than spilling breakers. Droplets are generated near the wave crest at young and intermediate wave ages, but at old wave ages, droplets are generated both near and behind the wave crest. It is also elucidated that the large-scale spanwise vortex induced by the wave plunging event plays an important role in suspending droplets. Our simulation result of the vertical profile of sea spray concentration is consistent with laboratory measurement reported in the literature.

Description: Energies, Vol. 10, Pages 1997: Digital-Control-Based Approximation of Optimal Wave Disturbances Attenuation for Nonlinear Offshore Platforms Energies doi: 10.3390/en10121997 Authors: Xiao-Fang Zhong Yu-Hong Sun Shi-Yuan Han Jin Zhou Dong Wang The irregular wave disturbance attenuation problem for jacket-type offshore platforms involving the nonlinear characteristics is studied. The main contribution is that a digital-control-based approximation of optimal wave disturbances attenuation controller (AOWDAC) is proposed based on iteration control theory, which consists of a feedback item of offshore state, a feedforward item of wave force and a nonlinear compensated component with iterative sequences. More specifically, by discussing the discrete model of nonlinear offshore platform subject to wave forces generated from the Joint North Sea Wave Project (JONSWAP) wave spectrum and linearized wave theory, the original wave disturbances attenuation problem is formulated as the nonlinear two-point-boundary-value (TPBV) problem. By introducing two vector sequences of system states and nonlinear compensated item, the solution of introduced nonlinear TPBV problem is obtained. Then, a numerical algorithm is designed to realize the feasibility of AOWDAC based on the deviation of performance index between the adjacent iteration processes. Finally, applied the proposed AOWDAC to a jacket-type offshore platform in Bohai Bay, the vibration amplitudes of the displacement and the velocity, and the required energy consumption can be reduced significantly.

Description: Entropy, Vol. 20, Pages 563: A New Underwater Acoustic Signal Denoising Technique Based on CEEMDAN, Mutual Information, Permutation Entropy, and Wavelet Threshold Denoising Entropy doi: 10.3390/e20080563 Authors: Yuxing Li Yaan Li Xiao Chen Jing Yu Hong Yang Long Wang Owing to the complexity of the ocean background noise, underwater acoustic signal denoising is one of the hotspot problems in the field of underwater acoustic signal processing. In this paper, we propose a new technique for underwater acoustic signal denoising based on complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN), mutual information (MI), permutation entropy (PE), and wavelet threshold denoising. CEEMDAN is an improved algorithm of empirical mode decomposition (EMD) and ensemble EMD (EEMD). First, CEEMDAN is employed to decompose noisy signals into many intrinsic mode functions (IMFs). IMFs can be divided into three parts: noise IMFs, noise-dominant IMFs, and real IMFs. Then, the noise IMFs can be identified on the basis of MIs of adjacent IMFs; the other two parts of IMFs can be distinguished based on the values of PE. Finally, noise IMFs were removed, and wavelet threshold denoising is applied to noise-dominant IMFs; we can obtain the final denoised signal by combining real IMFs and denoised noise-dominant IMFs. Simulation experiments were conducted by using simulated data, chaotic signals, and real underwater acoustic signals; the proposed denoising technique performs better than other existing denoising techniques, which is beneficial to the feature extraction of underwater acoustic signal.

Description: Sustainable watershed management (SWM) can be achieved through recognition and reflection upon the values of citizens. Collaborative governance consisting of citizens is crucial for successful SWM. Collaborative governance definitely requires an active participatory decision-making process that reflects citizens’ preferences. Citizen preference also tends to substantially change with life pattern and life quality. These shifts can be caused by slight variations in both social priorities and personal preferences for SWM. Therefore, collaborative water governance must be frequently renewed in response to citizens’ values through the participatory framework. The An’yang Stream in South Korea is generally regarded as a representative urban stream restoration case that has been successfully led by collaborative governance. By conducting individual surveys with citizens on-site, this study addresses how citizens’ preferences of the stream’s management have changed between 2005 and 2015. In addition, this study used three quantitative hydrologic vulnerability indices: potential flood damage (PFD), potential streamflow depletion (PSD), and potential water quality deterioration (PWQD). They can spatially quantify citizen preference using the Analytic Hierarchy Process (AHP), which can systematically derive citizens’ subjective relative-weighted preferences. In the end, this study identified critical differences in priorities in regard to vulnerable areas between in 2005 and in 2015.

Description: Sustainability, Vol. 9, Pages 1959: Inventory Analysis and Social Life Cycle Assessment of Greenhouse Gas Emissions from Waste-to-Energy Incineration in Taiwan Sustainability doi: 10.3390/su9111959 Authors: Yu-Tsang Lu Yuh-Ming Lee Chien-Yu Hong Waste-to-energy (WtE) incineration technology is widely used to solve the energy supply, greenhouse gas emissions, and waste generation problems in urban areas. In Taiwan, there are new laws and regulations that would affect greenhouse gas management of WtE incineration plants. This research aims to identify or raise key issues to be promoted for WtE incineration plants due to existing management systems and complex issues mixed with GHG, energy, and solid waste treatment. This study utilizes inventory analysis and social LCA (SLCA) approach on GHG management of WtE incineration plants in Taiwan to systematically identify materiality issues to be promoted. According to the results of materiality analysis for SLCA, this study generalizes four stakeholders, nine subcategories, and their 15 inventory indicators; and concludes that, among assessment results of 15 inventory indicators, three indicators are at a high level, four at a medium level, and eight at a low level. In total, 12 materiality issues are recognized. This study suggests WtE incineration plants should consider the following materiality issues with respect to priority: a systematic database and calculation methods, the goal and criteria of the laws and regulations, technology development toward circular economy and promotion activity or opportunity for local community and organization level.

Description: Author(s): ZhenYu Hong, Jie Zhang, and Bruce W. Drinkwater We observe distinct regimes of orbital angular momentum (OAM) transfer from two-dimensional Bessel-shaped acoustic vortices to matter. In a homogeneous diphasic mixture of microparticles and water, slow swirling about the vortex axis is seen. This effect is driven by the absorption of OAM across the... [Phys. Rev. Lett. 114, 214301] Published Thu May 28, 2015

Description: Author(s): Ting Chen, Ying Chen, Ming Gong, Yu-Hong Lei, Ning Li, Chuan Liu, Yu-Bin Liu, Zhao-Feng Liu, Jian-Ping Ma, Zhan-Lin Wang, and Jian-Bo Zhang (CLQCD Collaboration) In this exploratory lattice study, low-energy near threshold scattering of the ( D ¯ 1 D * ) ± meson system is analyzed using lattice QCD with N f = 2 twisted mass fermion configurations. Both s-wave ( J P = 0 − ) and p-wave ( J P = 1 + ) channels are investigated. It is found that the interaction between the two charmed… [Phys. Rev. D 93, 114501] Published Wed Jun 01, 2016

Description: Based on panel data of 28 manufacturing industries sectors in 2005–2015 years, this paper first estimated the level of 28 manufacturing industries sectors technological progress, and then, using panel threshold technology, calculated the impact of three environmental regulation change rates on technological progress change rate to analyze the relationship between environmental regulations and technology innovation. The results show that: (1) The influence of the change rates of waste gas, wastewater and solid waste’s environmental regulation intensity towards the change rate of production technological progress has two thresholds. Only the proper change rate of environmental regulation intensity can lead to a desired change rate of production technological progress. However, there are differences in the thresholds of the change rates of three kinds of environmental regulation intensities, and the optimal change rates of waste gas, wastewater and waste solid are 15.07%–55.31%, 17.06%–38.02% and 33.12%–47.99%, respectively. (2) In the change rates of waste gas, wastewater and waste solid’s environmental regulation intensity, there are 8, 10 and 3 industries at a reasonable level, respectively, while others industries are below or above the reasonable level and unable to stimulate technical and management innovation in enterprises. Hence, to achieve a win-win situation between environmental protection and production technological progress, different environmental regulation intensities should be planned according to different pollutants in various manufacturing industries.