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Search Results: 1 - 10 of 22948 matches for " Yichao He "
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An Improved Hybrid Encoding Cuckoo Search Algorithm for 0-1 Knapsack Problems
Yanhong Feng,Ke Jia,Yichao He
Computational Intelligence and Neuroscience , 2014, DOI: 10.1155/2014/970456
Abstract: Cuckoo search (CS) is a new robust swarm intelligence method that is based on the brood parasitism of some cuckoo species. In this paper, an improved hybrid encoding cuckoo search algorithm (ICS) with greedy strategy is put forward for solving 0-1 knapsack problems. First of all, for solving binary optimization problem with ICS, based on the idea of individual hybrid encoding, the cuckoo search over a continuous space is transformed into the synchronous evolution search over discrete space. Subsequently, the concept of confidence interval (CI) is introduced; hence, the new position updating is designed and genetic mutation with a small probability is introduced. The former enables the population to move towards the global best solution rapidly in every generation, and the latter can effectively prevent the ICS from trapping into the local optimum. Furthermore, the greedy transform method is used to repair the infeasible solution and optimize the feasible solution. Experiments with a large number of KP instances show the effectiveness of the proposed algorithm and its ability to achieve good quality solutions. 1. Introduction The combinatorial optimization plays a very important role in operational research, discrete mathematics, and computer science. The knapsack problem is one of the classical combinatorial optimization problems that are difficult to solve and it has been extensively studied since the pioneering work of Dantzig [1]. Generally speaking, if the classification of these methods that are used to solve such problems is based on the nature of the algorithm, they can be simply divided into two categories [2]: exact methods and heuristic methods. Exact methods, like enumeration method [3, 4], branch and bound [5], and dynamic programming [6], can give the exact solutions; nevertheless, in the worst case, it is required to take a long time to get a satisfactory solution; sometimes the time increases exponentially with the increment of the size of the instance. Recently, nature-inspired metaheuristic algorithms perform powerfully and efficiently in solving the diverse optimization problems, including combinatorial problem. Metaheuristic algorithms include genetic algorithm [7], particle swarm optimization [8], ant colony optimization [9], artificial bee colony algorithm [10], differential evolution algorithm [11], harmony search algorithm [12, 13], and krill herd algorithm [14–16]. As is mentioned above, metaheuristic methods have been proven to be an effective means to cope with the combinatorial optimization problems including 0-1 knapsack
Tax Contribution and Income Gap between Urban and Rural Areas in China  [PDF]
Yichao Yu
Open Journal of Social Sciences (JSS) , 2015, DOI: 10.4236/jss.2015.311023
Abstract: This article analyses the relationship of tax contribution and income gap between urban and rural areas. First of all, we comb their relationship from theoretical knowledge. Secondly, we use 2000- 2014 panel data of 29 provinces and cities in our country (except Tibet) to establish the fixed effects model for analysis. Results show that the improvement of tax contribution will expand the income gap between urban and rural areas. This is due to that turnover tax contribution is the most important part in the tax contribution. From the structural analysis, improvement of turnover tax and income tax contribution are not conducive to narrow the income gap between urban and rural areas. The improvement of property tax contribution is conducive to narrow the income gap between urban and rural areas. Finally, from the empirical results, we can give the policy suggestion of structural tax cuts and others.
An Efficient Algorithm of Logarithmic Transformation to Hirota Bilinear Form of KdV-type Bilinear Equation
Yichao Ye,Lihong Wang,Zhaowei Chang,Jingsong He
Physics , 2011, DOI: 10.1016/j.amc.2011.07.036
Abstract: In this paper, an efficient algorithm of logarithmic transformation to Hirota bilinear form of the KdV-type bilinear equation is established. In the algorithm, some properties of Hirota operator and logarithmic transformation are successfully applied, which helps to prove that the linear terms of the nonlinear partial differential equation play a crucial role in finding the Hirota bilinear form. Experimented with various integro-differential equations, our algorithm is proven to be more efficient than the algorithm referred by Zhou, Fu, and Li in getting the Hirota bilinear form, especially in achieving the coefficient of the logarithmic transformation.
Experimental demonstration of a multiphysics cloak: manipulating heat flux and electric current simultaneously
Yungui Ma,Yichao Liu,Muhammad Raza,Yudong Wang,Sailing He
Physics , 2014, DOI: 10.1103/PhysRevLett.113.205501
Abstract: In past years, triggered by their successful realizations in electromagnetics, invisible cloaks have experienced rapid development and have been widely pursued in many different fields, though so far only for a single physical system. In this letter we made an unprecedented experimental attempt to show a multidisciplinary framework designed on the basis of two different physical equations. The proposed structure has the exceptional capability to simultaneously control two different physical phenomena according to the predetermined evolution scenarios. As a proof of concept, we implemented an electric-thermal bifunctional device that can guide both electric current and heat flux "across" a strong 'scatter' (air cavity) and restore their original diffusion directions as if nothing exists along the paths, thus rending dual cloaking effects for objects placed inside the cavity. This bifunctional cloaking performance is also numerically verified for a point-source nonuniform excitation. Our results and the fabrication technique presented here will help broaden the current research scope for multiple disciplines and may pave a prominent way to manipulate multiple flows and create new functional devices, e.g., for on-chip applications.
An efficient plate heater with uniform surface temperature engineered with effective thermal materials
Yichao Liu,Wei Jiang,Sailing He,Yungui Ma
Physics , 2014, DOI: 10.1364/OE.22.017006
Abstract: Extended from its electromagnetic counterpart, transformation thermodynamics applied to thermal conduction equations can map a virtual geometry into a physical thermal medium, realizing the manipulation of heat flux with almost arbitrarily desired diffusion paths, which provides unprecedented opportunities to create thermal devices unconceivable or deemed impossible before. In this work we employ this technique to design an efficient plate heater that can transiently achieve a large surface of uniform temperature powered by a small thermal source. As opposed to the traditional approach of relying on the deployment of a resistor network, our approach fully takes advantage of an advanced functional material system to guide the heat flux to achieve the desired temperature heating profile. A different set of material parameters for the transformed device has been developed, offering the parametric freedom for practical applications. As a proof of concept, the proposed devices are implemented with engineered thermal materials and show desired heating behaviors consistent with numerical simulations. Unique applications for these devices can be envisioned where stringent temperature uniformity and a compact heat source are both demanded.
A Research of Real-Time Pricing Mechanism and Its Characteristics  [PDF]
Yichao Dong, Bin Zou
Journal of Power and Energy Engineering (JPEE) , 2015, DOI: 10.4236/jpee.2015.34033

Real-Time Pricing (RTP) is proposed as an effective Demand-Side Management (DSM) to adjust the load curve in order to achieve the peak load shifting. At the same time, the RTP mechanism can also raise the revenue of the supply-side and reduce the electricity expenses of consumers to achieve a win-win situation. In this paper, a real-time pricing algorithm based on price elasticity theory is proposed to analyze the energy consumption and the response of the consumers in smart grid structure. We consider a smart grid equipped with smart meters and two-way communication system. By using real data to simulate the proposed model, some characteristics of RTP are summarized as follows: 1) Under the condition of the real data, the adjustment of load curve and reducing the expenses of consumers is obviously. But the profit of power supplier is difficult to ensure. If we balance the profits of both sides, the supplier and consumers, the profits of both sides and the adjustment of load curve will be relatively limited. 2) If assuming the response degree of consumers to real-time prices is high enough, the RTP mechanism can achieve the expected effect. 3, If the cost of supply-side (day-ahead price) fluctuates dramatically, the profits of both sides can be ensured to achieve the expected effect.

First experimental demonstration of an isotropic electromagnetic cloak with strict conformal mapping
Yungui Ma,Yichao Liu,Lu Lan,Tiantian Wu,Wei Jiang,C. K. Ong,Sailing He
Physics , 2013, DOI: 10.1038/srep02182
Abstract: In the past years quasi-conformal mapping has been typically used to design broadband electromagnetic cloaks. However, this technique has some inherit practical limitations such as the lateral beam shift, rendering the device visible or difficult to hide a large object. In this work we circumvent these issues by using strict conformal mapping to build the first isotropic cloak. Microwave near-field measurement shows that our device (with dielectric constant larger than unity everywhere) has a very good cloaking performance and a broad frequency response. The present dielectric approach could be technically extended to the fabrication of other conformal devices at higher frequencies.
Three-dimensional magnetic cloak working from DC to 250 kHz
Jianfei Zhu,Wei Jiang,Yichao Liu,Ge Yin,Jun Yuan,Sailing He,Yungui Ma
Physics , 2015, DOI: 10.1038/ncomms9931
Abstract: Invisible cloaking is one of major outcomes of the metamaterial research, but the practical potential, in particular for high frequencies (e.g., microwave to visible light), is fatally challenged by the complex material properties they usually demand. On the other hand, it will be advantageous and also technologically instrumental to design cloaking devices for applications at low frequencies where electromagnetic components are favorably uncoupled. In this work, we vastly develop the bilayer approach to create a three-dimensional magnetic cloak able to work in both static and dynamic fields. Under the quasi-static approximation, we demonstrate a perfect magnetic cloaking device with a large frequency band from zero to 250 kHz. The practical potential of our device is experimentally verified by using a commercial metal detector, which may lead us to having a real cloaking application where the dynamic magnetic field can be manipulated in desired ways.
The Study of the Application Status of Fair Value Accounting in China
Yichao Liu
International Journal of Business and Management , 2010, DOI: 10.5539/ijbm.v5n9p155
Abstract: With more trade frictions as well as increasingly frequent and expanded trades between developed countries and China after its entry into WTO, fair value accounting has found its way even deeper into people’s hearts because it can reflect assets income and valid value of debt payment, offer exact information support for relevant decision makers, and more importantly, narrow the gap between China’s accounting standards and international ones as soon as possible. From the perspectives of concept, history of application, origin analysis and countermeasures, this paper conducts research and exploration into the application of fair value accounting in China.
p-adic Monodromy of the Universal Deformation of a HW-cyclic Barsotti-Tate Group
Yichao Tian
Mathematics , 2007,
Abstract: Let k be an algebraically closed field of characteristic $p>0$, and $G_0$ be a Barsotti-Tate group (or $p$-divisible group) over k. We denote by $S$ the "algebraic" local moduli in characteristic p of $G_0$, by $G$ the universal deformation of $G_0$ over $S$, and by $U\subset S$ the ordinary locus of $G$. The etale part of $G$ over $U$ gives rise to a monodromy representation $\rho$ of the fundamental group of $U$ on the Tate module of $G$. Motivated by a famous theorem of Igusa, we prove in this article that $\rho$ is surjective if $G_0$ is connected and HW-cyclic. This latter condition is equivalent to that Oort's $a$-number of $G_0$ equals 1, and it is satisfied by all connected one-dimensional Barsotti-Tate groups over $k$.
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