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Shasha ZHAO Qi ZHU Guangwei ZHU Hongbo ZHU
The dynamic competition between two bounded rational mobile virtual network operators (MVNOs) in a duopoly spectrum market is investigated. A two stage game is employed to model the interaction of the MVNOs and the quality of service of the secondary users is taken into account. The evolutionary game theory is introduced to model the dynamic strategy selections of MVNOs. Using replicated dynamics, the proposed evolutionary game algorithm can converge to a unique evolutionary stable strategy. Simulation results verify that the proposed algorithm can make the MVNOs adaptively adjust the strategies to approximate optimal solution.
Changsheng YIN Ruopeng YANG Wei ZHU Xiaofei ZOU Junda ZHANG
Aiming at the problems of traditional algorithms that require high prior knowledge and weak timeliness, this paper proposes an emergency communication network topology planning method based on deep reinforcement learning. Based on the characteristics of the emergency communication network, and drawing on chess, we map the node layout and topology planning problems in the network planning to chess game problems; The two factors of network coverage and connectivity are considered to construct the evaluation criteria for network planning; The method of combining Monte Carlo tree search and self-game is used to realize network planning sample data generation, and the network planning strategy network and value network structure based on residual network are designed. On this basis, the model was constructed and trained based on Tensorflow library. Simulation results show that the proposed planning method can effectively implement intelligent planning of network topology, and has excellent timeliness and feasibility.
Hongwei ZHU Ilie I. LUICAN Florin BALASA Dhiraj K. PRADHAN
In real-time data-dominated communication and multimedia processing applications, a multi-layer memory hierarchy is typically used to enhance the system performance and also to reduce the energy consumption. Savings of dynamic energy can be obtained by accessing frequently used data from smaller on-chip memories rather than from large background memories. This paper focuses on the reduction of the dynamic energy consumption in the memory subsystem of multidimensional signal processing systems, starting from the high-level algorithmic specification of the application. The paper presents a formal model which identifies those parts of arrays more intensely accessed, taking also into account the relative lifetimes of the signals. Tested on a two-layer memory hierarchy, this model led to savings of dynamic energy from 40% to over 70% relative to the energy used in the case of flat memory designs.
Wei HONG Shiwen HE Haiming WANG Guangqi YANG Yongming HUANG Jixing CHEN Jianyi ZHOU Xiaowei ZHU Nianzhu ZHANG Jianfeng ZHAI Luxi YANG Zhihao JIANG Chao YU
This paper presents an overview of the advance of the China millimeter-wave multiple gigabit (CMMG) wireless local area network (WLAN) system which operates in the 45 GHz frequency band. The CMMG WLAN system adopts the multiple antennas technologies to support data rate up to 15Gbps. During the progress of CMMG WLAN standardization, some new key technologies were introduced to adapt the millimeter-wave characteristic, including the usage of the zero correlation zone (ZCZ) sequence, a novel lower density parity check code (LDPC)-based packet encoding, and multiple input multiple output (MIMO) single carrier transmission. Extensive numerical results and system prototype test are also given to validate the performance of the technologies adopted by CMMG WLAN system.
Hongwei ZHU Ilie I. LUICAN Florin BALASA
In real-time multimedia processing systems a very large part of the power consumption is due to the data storage and data transfer. Moreover, the area cost is often largely dominated by the memory modules. In deriving an optimized (for area and/or power) memory architecture, memory size computation is an important step in the exploration of the possible algorithmic specifications of multimedia applications. This paper presents a novel non-scalar approach for computing exactly the memory size in real-time multimedia algorithms. This methodology uses both algebraic techniques specific to the data-flow analysis used in modern compilers and, also, more recent advances in the theory of polyhedra. In contrast with all the previous works which are only estimation methods, this approach performs exact memory computations even for applications significantly large in terms of the code size, number of scalars, and number of array references.
Jianfei CHEN Xiaowei ZHU Yuehua LI
Synthetic aperture interferometric radiometer (SAIR) is a powerful sensors for high-resolution imaging. However, because of the observation errors and small number of visibility sampling points, the accuracy of reconstructed images is usually low. To overcome this deficiency, a novel super-resolution imaging (SrI) method based on super-resolution reconstruction idea is proposed in this paper. In SrI method, sparse visibility functions are first measured at different observation locations. Then the sparse visibility functions are utilized to simultaneously construct the fusion visibility function and the fusion imaging model. Finally, the high-resolution image is reconstructed by solving the sparse optimization of fusion imaging model. The simulation results demonstrate that the proposed SrI method has higher reconstruction accuracy and can improve the imaging quality of SAIR effectively.
Florin BALASA Ilie I. LUICAN Hongwei ZHU Doru V. NASUI
Many signal processing systems, particularly in the multimedia and telecommunication domains, are synthesized to execute data-intensive applications: their cost related aspects -- namely power consumption and chip area -- are heavily influenced, if not dominated, by the data access and storage aspects. This paper presents an energy-aware memory allocation methodology. Starting from the high-level behavioral specification of a given application, this framework performs the assignment of the multidimensional signals to the memory layers -- the on-chip scratch-pad memory and the off-chip main memory -- the goal being the reduction of the dynamic energy consumption in the memory subsystem. Based on the assignment results, the framework subsequently performs the mapping of signals into both memory layers such that the overall amount of data storage be reduced. This software system yields a complete allocation solution: the exact storage amount on each memory layer, the mapping functions that determine the exact locations for any array element (scalar signal) in the specification, and an estimation of the dynamic energy consumption in the memory subsystem.
Xiaoying TAN Yuchun GUO Yishuai CHEN Wei ZHU
The Collaborative Filtering (CF) algorithms work fairly well in personalized recommendation except in sparse data environment. To deal with the sparsity problem, researchers either take into account auxiliary information extracted from additional data resources, or set the missing ratings with default values, e.g., video popularity. Nevertheless, the former often costs high and incurs difficulty in knowledge transference whereas the latter degrades the accuracy and coverage of recommendation results. To our best knowledge, few literatures take advantage of users' preference on video popularity to tackle this problem. In this paper, we intend to enhance the performance of recommendation algorithm via the inference of the users' popularity preferences (PPs), especially in a sparse data environment. We propose a scheme to aggregate users' PPs and a Collaborative Filtering based algorithm to make the inference of PP feasible and effective from a small number of watching records. We modify a k-Nearest-Neighbor recommendation algorithm and a Matrix Factorization algorithm via introducing the inferred PP. Experiments on a large-scale commercial dataset show that the modified algorithm outperforms the original CF algorithms on both the recommendation accuracy and coverage. The significance of improvement is significant especially with the data sparsity.