Yangyang Wang¹, Rongrong Ni^1,*, Yao Zhao¹, Min Xian²

CMC-Computers, Materials & Continua, Vol.55, No.2, pp. 255-265, 2018, DOI:10.3970/cmc.2018.01732

Abstract In this paper, two methods are proposed to embed visual watermark into direct binary search (DBS) halftone images, which are called Adjusted Direct Binary Search (ADBS) and Dual Adjusted Direct Binary Search (DADBS). DADBS is an improved version of ADBS. By using the proposed methods, the visual watermark will be embedded into two halftone images separately, thus, the watermark can be revealed when these two halftone images are overlaid. Experimental results show that both methods can achieve excellent image visual quality and decoded visual patterns. More >

Yuling Liu^1,*, Hua Peng¹, Jie Wang²

CMC-Computers, Materials & Continua, Vol.55, No.1, pp. 37-57, 2018, DOI:10.3970/cmc.2018.055.037

Abstract Data outsourcing has become an important application of cloud computing. Driven by the growing security demands of data outsourcing applications, sensitive data have to be encrypted before outsourcing. Therefore, how to properly encrypt data in a way that the encrypted and remotely stored data can still be queried has become a challenging issue. Searchable encryption scheme is proposed to allow users to search over encrypted data. However, most searchable encryption schemes do not consider search result diversification, resulting in information redundancy. In this paper, a verifiable diversity ranking search scheme over encrypted outsourced data is proposed while preserving privacy in… More >

Guo Zhao^1,2, Jiang Guo^1,2, Hao Qiang³

CMC-Computers, Materials & Continua, Vol.53, No.4, pp. 343-356, 2017, DOI:10.3970/cmc.2017.053.343

Abstract As a good measure to tackle the challenges from energy shortages and environmental pollution, Electric Vehicles (EVs) have entered a period of rapid growth. Battery swapping station is a very important way of energy supply to EVs, and it is urgently needed to explore a coordinated control strategy to effectively smooth the load fluctuation in order to adopt the large-scale EVs. Considering bidirectional power flow between the station and power grid, this paper proposed a SFLA-based control strategy to smooth the load profile. Finally, compared simulations were performed according to the related data. Compared to particle swarm optimization (PSO) method,… More >

Haolong Chen^1,2, Bo Yu¹, Huanlin Zhou^1*, Zeng Meng¹

CMC-Computers, Materials & Continua, Vol.53, No.4, pp. 271-290, 2017, DOI:10.3970/cmc.2017.053.271

Abstract The cuckoo search algorithm (CS) is improved by using the conjugate gradient method(CGM), and the CS-CGM is proposed. The unknown inner boundary shapes are generated randomly and evolved by Lévy flights and elimination mechanism in the CS and CS-CGM. The CS, CGM and CS-CGM are examined for the prediction of a pipe’s inner surface. The direct problem is two-dimensional transient heat conduction in functionally graded materials (FGMs). Firstly, the radial integration boundary element method (RIBEM) is applied to solve the direct problem. Then the three methods are compared to identify the pipe’s inner surfacewith the information of measured temperatures. Finally,… More >

Shifeng Xue^1,2, Xiuxing Zhu^1,2, Lin Zhang³, Shenghu Zhu⁴, Guigen Ye^1,5

CMC-Computers, Materials & Continua, Vol.51, No.1, pp. 21-42, 2016, DOI:10.3970/cmc.2016.051.021

Abstract A perforating hole is a channel through which the oil and gas in a reservoir pass into the production well bore. During the process of perforating due to explosion, the surrounding sandstone will be damaged to a certain extent, which will increase the well bore skin and lead to the decrease of production consequently. In this work a mechanical model of perforating damage is developed to describe the influences of perforating due to explosion on the porosity and permeability of the surrounding sandstone near the compaction zone. Based on this developed model, the important data related to the damage of… More >

CMC-Computers, Materials & Continua, Vol.47, No.3, pp. 179-201, 2015, DOI:10.3970/cmc.2015.047.179

Abstract Discontinuous smoothed particle hydrodynamics (DSPH) method based on traditional SPH method, which can be used to simulate discontinuous physics problems near interface or boundary. Previous works showed that DSPH method has a good application prospect [Xu et al, 2013], but further verification and improvement are demanded. In this paper, we investigate the accuracy of DSPH method by some numerical models. Moreover, to improve the accuracy of DSPH method, first order and second order multidimensional RDSPH methods are proposed by following the idea of restoring particle consistency in SPH (RSPH) method which has shown good results in the improvement of particle… More >

Yi Xue^1,2, Feng Gao^1,2,3, Xingguang Liu⁴, Xiru Li²

CMC-Computers, Materials & Continua, Vol.47, No.2, pp. 127-141, 2015, DOI:10.3970/cmc.2015.047.127

Abstract In order to study the effect of high pressure water jet cutting technology on the permeability of single coal seam, we use the damage variable to describe the fracture distribution of coal seam, develop the 3-D finite element program based on the damage theory, and then analyze the damage distribution of coal seam after drilling and slotting. Using MTS815 rock mechanics testing system and the permeability test system, we conduct the permeability test and get the relationship between permeability and damage. Based on the damage distribution of coal seam after drilling and slotting and the permeability change law, we analyze… More >

Xiaoyi Liang¹, Zhen Yang^1,2, Xingsheng Gu³, Licheng Ling¹

CMC-Computers, Materials & Continua, Vol.13, No.2, pp. 135-152, 2009, DOI:10.3970/cmc.2009.013.135

Abstract Supercapacitors, also called electrical double-layer capacitors (EDLCs), occupy a region between batteries and dielectric capacitors on the Ragone plot describing the relation between energy and power. BET specific surface area and specific capacitance are two important electrochemical property parameters for activated carbon EDLCs, which are usually tested by experimental method. However, it is misspent time to repeat lots of experiments for EDLCs' studies. In this investigation, we developed one theoretical model based on improved particle swarm optimization algorithm back propagation (PSO-BP) neural network (NN) to simulate and optimize BET specific surface area and specific capacitance. Comparative studies between the predicted… More >