6,330 research outputs found
The Game Between Companies and Farmers in Controlling Pig Environmental Pollution
To reduce the waste pollution in the “company + peasant household” special cultivation mode, an effective countermeasure is to help farmers use waste to integrate planting with breeding. But considering the farm are not surrounding the pig farm, it exists long distance transportation of waste, and the household economic crops of every peasant are not unified. I also take into account of the planting and pest control technology as well as the final sales. Then the author puts forward four feasible schemes: The first is farmers use waste to grow their own crops, the second is the company contracts farmers land using waste to plant, the third is companies develop crops planting and using waste, the last is using the waste to cultivate crops by means of “company + peasant household”. Based on the theory discussion and game derivation of the four ways, I made the conclusion that “company + peasant household” mode is more effective to solve the problem. It realizes the symbiotic association of planting and breeding, not only can solve the problem of environmental pollution, but also brings a new profit growth point to the companies, and makes the farmers earn more income. More importantly, the scientific farming method can improve the utilization of resources and optimize the allocation of resources
Robust Transmissions in Wireless Powered Multi-Relay Networks with Chance Interference Constraints
In this paper, we consider a wireless powered multi-relay network in which a
multi-antenna hybrid access point underlaying a cellular system transmits
information to distant receivers. Multiple relays capable of energy harvesting
are deployed in the network to assist the information transmission. The hybrid
access point can wirelessly supply energy to the relays, achieving multi-user
gains from signal and energy cooperation. We propose a joint optimization for
signal beamforming of the hybrid access point as well as wireless energy
harvesting and collaborative beamforming strategies of the relays. The
objective is to maximize network throughput subject to probabilistic
interference constraints at the cellular user equipment. We formulate the
throughput maximization with both the time-switching and power-splitting
schemes, which impose very different couplings between the operating parameters
for wireless power and information transfer. Although the optimization problems
are inherently non-convex, they share similar structural properties that can be
leveraged for efficient algorithm design. In particular, by exploiting
monotonicity in the throughput, we maximize it iteratively via customized
polyblock approximation with reduced complexity. The numerical results show
that the proposed algorithms can achieve close to optimal performance in terms
of the energy efficiency and throughput.Comment: 14 pages, 8 figure
Genetic learning particle swarm optimization
Social learning in particle swarm optimization (PSO) helps collective efficiency, whereas individual reproduction in genetic algorithm (GA) facilitates global effectiveness. This observation recently leads to hybridizing PSO with GA for performance enhancement. However, existing work uses a mechanistic parallel superposition and research has shown that construction of superior exemplars in PSO is more effective. Hence, this paper first develops a new framework so as to organically hybridize PSO with another optimization technique for “learning.” This leads to a generalized “learning PSO” paradigm, the *L-PSO. The paradigm is composed of two cascading layers, the first for exemplar generation and the second for particle updates as per a normal PSO algorithm. Using genetic evolution to breed promising exemplars for PSO, a specific novel *L-PSO algorithm is proposed in the paper, termed genetic learning PSO (GL-PSO). In particular, genetic operators are used to generate exemplars from which particles learn and, in turn, historical search information of particles provides guidance to the evolution of the exemplars. By performing crossover, mutation, and selection on the historical information of particles, the constructed exemplars are not only well diversified, but also high qualified. Under such guidance, the global search ability and search efficiency of PSO are both enhanced. The proposed GL-PSO is tested on 42 benchmark functions widely adopted in the literature. Experimental results verify the effectiveness, efficiency, robustness, and scalability of the GL-PSO
Comparison of two efficient methods for calculating partition functions
In the long-time pursuit of the solution to calculate the partition function
(or free energy) of condensed matter, Monte-Carlo-based nested sampling should
be the state-of-the-art method, and very recently, we established a direct
integral approach that works at least four orders faster. In present work, the
above two methods were applied to solid argon at temperatures up to K, and
the derived internal energy and pressure were compared with the molecular
dynamics simulation as well as experimental measurements, showing that the
calculation precision of our approach is about 10 times higher than that of the
nested sampling method.Comment: 6 pages, 4 figure
Tunable Chiral Bound States in a Dimer Chain of Coupled Resonators
We study the chiral feature in a system composed of one two-level emitter
(TLE) and a one dimensional (1D) dimer chain of coupled resonators with the
alternate single-photon energies. In the single-excitation subspace, this
system not only possesses two energy bands with propagating states, but also
possesses chiral bound states. The number of chiral bound states depends on the
coupling forms between the TLE and the dimer chain. It is found that when the
TLE is locally coupled to one resonator of the dimer chain, the bound-state
that has mirror reflection symmetry is not a chiral one. When the TLE is
nonlocally coupled to two adjacent resonators, three chiral bound states arise
due to the mirror symmetry breaking. The chirality of these bound states can be
tuned by changing the energy differences of single photon in the adjacent
resonators, the coupling strengths and the transition energy of the TLE. The
chirality behaviour of the ordinary two bound states outside the energy bands
is quite different from the one of the emerging bound state inside the energy
gap. The almost perfect chiral bound states can be achieved at certain
parameters as a result of completely destructive interference.Comment: 7 pages, 4 postscript figure
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