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Attribute-based encryption scheme with verifiable search and non-monotonic access structure
Suqing LIN, Shuhua ZHANG
Journal of Computer Applications    2022, 42 (9): 2772-2779.   DOI: 10.11772/j.issn.1001-9081.2021081446
Abstract255)   HTML5)    PDF (975KB)(92)       Save

Most existing attribute-based keyword search schemes only support monotonic access structure and lack efficient verification for search results. Aiming at these problems, a ciphertext keyword search attribute-based encryption scheme with verifiable search and non-monotonic access structure was proposed. Firstly, the polynomials were constructed by the attribute values, and the fine-grained ciphertext search permission setting was accomplished by divisibility property of the polynomials. Then, both keyword search and outsourced decryption were performed by the cloud servicer without revealing any private information. Finally, the search result verification was realized by utilizing the proposed commitment scheme. The proposed scheme supports multiple functions such as non-monotonic access structure, fine-grained search, data sharing, outsourced decryption, and verifiable search. Under the augmented Multi-Sequence of Exponents Decisional Diffie-Hellman (aMSE-DDH) assumption, it can be proved that this scheme has selective indistinguishability security under chosen ciphertext attacks and under chosen keyword attacks, respectively, in the random oracle model. Experimental results show that the terminal decryption time of the proposed scheme is not related to the attribute number, and is about 12.9 ms.

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Hybrid ITÖ algorithm for multi-scale colored traveling salesman problem
Shuning HAN, Min XU, Xueshi DONG, Qing LIN, Fanfan SHEN
Journal of Computer Applications    2022, 42 (3): 695-700.   DOI: 10.11772/j.issn.1001-9081.2021040776
Abstract289)   HTML11)    PDF (474KB)(97)       Save

Colored Traveling Salesman Problem (CTSP) is a variant of Multiple Traveling Salesmen Problem (MTSP) and Traveling Salesman Problem (TSP), which can be applied to the engineering problems such as Multi-machine Engineering System (MES) with overlapping workspace. CTSP is an NP complete problem, although related studies have attempted to solve the problem by Genetic Algorithm (SA), Simulated Annealing (SA) algorithm and some other methods, but they solve the problem at a limited scale and with unsatisfactory speed and solution quality. Therefore, a hybrid IT? algorithm combined with Uniform Design (UD), Ant Colony Optimization (ACO) and IT? algorithm was proposed to solve this problem, namely UDHIT?. UD was applied to choose the appropriate combination of parameters of the UDHIT? algorithm, the probabilistic graphic model of ACO was used to generate feasible solutions, and the drift operator and volatility operator of IT? were used to optimize the solutions. Experimental results show that the UDHIT? algorithm can demonstrate improvement over the traditional GA, ACO and IT? algorithm for the multi-scale CTSP problems in terms of best solution and average solution.

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Text-to-image synthesis method based on multi-level progressive resolution generative adversarial networks
XU Yining, HE Xiaohai, ZHANG Jin, QING Linbo
Journal of Computer Applications    2020, 40 (12): 3612-3617.   DOI: 10.11772/j.issn.1001-9081.2020040575
Abstract345)      PDF (1238KB)(348)       Save
To address the problem that the results of text-to-image synthesis tasks have wrong target structures and unclear image textures, a Multi-level Progressive Resolution Generative Adversarial Network (MPRGAN) model was proposed based on Attentional Generative Adversarial Network (AttnGAN). Firstly, a semantic separation-fusion generation module was used in low-resolution layer, and the text feature was separated into three feature vectors by the guidance of self-attention mechanism and the feature vectors were used to generate feature maps respectively. Then, the feature maps were fused into low-resolution map, and the mask images were used as semantic constraints to improve the stability of the low-resolution generator. Finally, the progressive resolution residual structure was adopted in high-resolution layers. At the same time, the word attention mechanism and pixel shuffle were combined to further improve the quality of the generated images. Experimental results showed that, the Inception Score (IS) of the proposed model reaches 4.70 and 3.53 respectively on datasets of Caltech-UCSD Birds-200-2011 (CUB-200-2011) and 102 category flower dataset (Oxford-102), which are 7.80% and 3.82% higher than those of AttnGAN, respectively. The MPRGAN model can solve the instability problem of structure generation to a certain extent, and the images generated by the proposed model is closer to the real images.
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Wavelet domain distributed depth map video coding based on non-uniform quantization
CHEN Zhenzhen, QING Linbo, HE Xiaohai, WANG Yun
Journal of Computer Applications    2016, 36 (4): 1080-1084.   DOI: 10.11772/j.issn.1001-9081.2016.04.1080
Abstract487)      PDF (734KB)(388)       Save
In order to improve the decoding quality of depth map video in Distributed Multi-view Video plus Depth (DMVD) coding, a new non-uniform quantization scheme based on the sub-band layer and sub-band coefficients was proposed in wavelet domain Distributed Video Coding (DVC). The main idea was allocating more bits to pixels belong to the edge of depth map and consequently improving the quality of the depth map. According to the distribution characteristics of the wavelet coefficients of depth map, the low frequency wavelet coefficients of layer- N kept the uniform quantization scheme, while the high frequency wavelet coefficients of all layers used the non-uniform quantization scheme. For the high frequency wavelet coefficients around "0", larger quantization step was adopted. As the amplitude of the high frequency wavelet coefficients increased, the quantization step decreased, with finer quantization and the quality of the edge was improved consequently. The experimental results show that, for "Dancer" and "PoznanHall2" depth sequence with more edges, the proposed scheme can achieve up to 1.2 dB in terms of the Rate-Distortion (R-D) performance improvement by improving the quality of edges; for "Newspaper" and "Balloons" depth sequences with less edges, the proposed scheme can still get 0.3 dB of the R-D performance.
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