- Fan Li;Chenfei Tian;Ting Li;Yu Wang;
Mobile social sensing network is one kind of emerging networks in which sensing tasks are performed by mobile users and sensing data are shared and collected by leveraging the intermittent inter-contacts among mobile users. Traditional ad hoc routing protocols are inapplicable or perform poorly for data collection or data sharing in such mobile social networks because nodes are seldom fully connected. In recent years, many routing protocols(especially social-based routing) are proposed to improve the delivery ratio in mobile social networks, but most of them do not consider the load of nodes thus may lead to unbalanced energy consumption among nodes. In this paper, we propose a simple Energy Efficient framework for Social-based Routing(EE-SR) in mobile social sensing networks to balance the load of nodes while maintaining the delivery ratio within an acceptable range by limiting the chances of forwarding in traditional social-based routing. Furthermore, we also propose an improved version of EE-SR to dynamically adjust the controlling parameter. Simulation results on real-life mobile traces demonstrate the efficiency of our proposed framework.
2016年04期 v.21 363-373页 [查看摘要][在线阅读][下载 2015K] [下载次数：37 ] |[网刊下载次数：0 ] |[引用频次：1 ] |[阅读次数：0 ] - Ran Bi;Yingshu Li;Xu Zheng;
For desirable quality of service, content providers aim at covering content requests by large network caches. Content caching has been considered as a fundamental module in network architecture. There exist few studies on the optimization of content caching. Most existing works focus on the design of content measurement,and the cached content is replaced by a new one based on the given metric. Therefore, the performance for service provision with multiple levels is decreased. This paper investigates the problem of finding optimal timer for each content. According to the given timer, the caching policies determine whether to cache a content and which existing content should be replaced, when a content miss occurs. Aiming to maximize the aggregate utility with capacity constraint, this problem is formalized as an integer optimization problem. A linear programming based approximation algorithm is proposed, and the approximation ratio is proved. Furthermore, the problem of content caching with relaxed constraints is given. A Lagrange multiplier based approximation algorithm with polynomial time complexity is proposed. Experimental results show that the proposed algorithms have better performance.
2016年04期 v.21 374-384页 [查看摘要][在线阅读][下载 751K] [下载次数：18 ] |[网刊下载次数：0 ] |[引用频次：2 ] |[阅读次数：0 ] - Haiping Huang;Tianhe Gong;Ping Chen;Reza Malekian;Tao Chen;
Numerous privacy-preserving issues have emerged along with the fast development of the Internet of Things. In addressing privacy protection problems in Wireless Sensor Networks(WSN), secure multi-party computation is considered vital, where obtaining the Euclidian distance between two nodes with no disclosure of either side's secrets has become the focus of location-privacy-related applications. This paper proposes a novel Privacy-Preserving Scalar Product Protocol(PPSPP) for wireless sensor networks. Based on PPSPP, we then propose a Homomorphic-Encryption-based Euclidean Distance Protocol(HEEDP) without third parties. This protocol can achieve secure distance computation between two sensor nodes. Correctness proofs of PPSPP and HEEDP are provided, followed by security validation and analysis. Performance evaluations via comparisons among similar protocols demonstrate that HEEDP is superior; it is most efficient in terms of both communication and computation on a wide range of data types, especially in wireless sensor networks.
2016年04期 v.21 385-396页 [查看摘要][在线阅读][下载 808K] [下载次数：41 ] |[网刊下载次数：0 ] |[引用频次：16 ] |[阅读次数：0 ] - Fu Xiao;Xiekun Yang;Meng Yang;Lijuan Sun;Ruchuan Wang;Panlong Yang;
Coverage is an important issue in the area of wireless sensor networks, which reflects the monitoring quality of the sensor networks in scenes. Most sensor coverage research focuses on the ideal two-dimensional(2-D) plane and full three-dimensional(3-D) space. However, in many real-world applications, the target field is a3-D complex surface, which makes conventional methods unsuitable. In this paper, we study the coverage problem in directional sensor networks for complex 3-D terrains, and design a new surface coverage algorithm. Based on a 3-D directional sensing model of nodes, this algorithm employs grid division, simulated annealing, and local optimum ideas to improve the area coverage ratio by optimizing the position coordinates and the deviation angles of the nodes, which results in coverage enhancement for complex 3-D terrains. We also conduct extensive simulations to evaluate the performance of our algorithms.
2016年04期 v.21 397-406页 [查看摘要][在线阅读][下载 1005K] [下载次数：60 ] |[网刊下载次数：0 ] |[引用频次：10 ] |[阅读次数：0 ] - Shuxian Jia;Guiyuan Jiang;Peilan He;Jigang Wu;
Network virtualization is a promising approach for resource management that allows customized Virtual Networks(VNs) to be multiplexed on a shared physical infrastructure. A key function that network virtualization can provide is Virtual Network Embedding(VNE), which maps virtual networks requested by users to a shared substrate network maintained by an Internet service provider. Existing research has worked on this, but has primarily focused on maximizing the revenue of the Internet service provider. In this paper, we consider energy-aware virtual network embedding, which aims at minimizing the energy consumption for embedding virtual networks in a substrate network. In our optimization model, we consider energy consumption of both links and nodes. We propose an efficient heuristic to assign virtual nodes to appropriate substrate nodes based on priority, where existing activated nodes have higher priority for hosting newly arrived virtual nodes. In addition, our proposed algorithm can take advantage of activated links for embedding virtual links so as to minimize total energy consumption. The simulation results show that, for all the cases considered, our algorithm can improve upon previous work by an average of12.6% on acceptance rate, while the consumed energy can be reduced by 12.34% on average.
2016年04期 v.21 407-414页 [查看摘要][在线阅读][下载 1083K] [下载次数：45 ] |[网刊下载次数：0 ] |[引用频次：12 ] |[阅读次数：0 ]
- Yi Yang;Wenguang Chen;
Classification is an important machine learning problem, and decision tree construction algorithms are an important class of solutions to this problem. Rain Forest is a scalable way to implement decision tree construction algorithms. It consists of several algorithms, of which the best one is a hybrid between a traditional recursive implementation and an iterative implementation which uses more memory but involves less write operations. We propose an optimized algorithm inspired by Rain Forest. By using a more sophisticated switching criterion between the two algorithms, we are able to get a performance gain even when all statistical information fits in memory. Evaluations show that our method can achieve a performance boost of 2.8 times in average than the traditional recursive implementation.
2016年04期 v.21 415-425页 [查看摘要][在线阅读][下载 1030K] [下载次数：109 ] |[网刊下载次数：0 ] |[引用频次：30 ] |[阅读次数：0 ] - Jietao Dong;Linxuan Zhang;Tianyuan Xiao;
In-house part supply affects the efficiency of mixed-model assembly lines considerably. Hence, we propose a reliable Just-In-Time part supply strategy with the use of decentralized supermarkets. For a given production sequence and line layout, the proposed strategy schedules tow train routing and delivery problems jointly to minimize the number of employed town trains and the traveling time, while ensuring that stations never run out of parts. To solve this problem, a mathematical formulation is proposed for each sub-problem aiming at minimizing supply cost. Then, a dynamic programming algorithm for routing and a greedy algorithm for delivery are developed, both of which are of polynomial runtime. Finally, a computational study is implemented to validate the effectiveness of the strategy, and to investigate the effects of the delivery capacity of tow trains and storage capacity of stations on supply cost.
2016年04期 v.21 426-434页 [查看摘要][在线阅读][下载 632K] [下载次数：46 ] |[网刊下载次数：0 ] |[引用频次：14 ] |[阅读次数：0 ] - Wentian Mi;Shih-Wen Chiu;Tao Xue;Yuanquan Chen;Hanyu Qi;Yi Yang;Kea-Tiong Tang;Tian-Ling Ren;
Graphene has been widely used in gas-sensing applications due to its large specific surface area and strong adsorption ability. Among different forms of graphene used as gas-sensing materials, reduced graphene oxide is one of the most convenient and economical materials to integrate with Si-based electronics, which is very important to graphene-based gas sensors. In addition, the stacking structure of graphene oxide flakes facilitates absorption and detection of gas molecules. Based on reduced graphene oxide, a highly sensitive and portable gas-sensing system was demonstrated here. Solution-based graphene oxide was cast on a chip like a TF memory card and then reduced thermally. A signal acquisition system was designed to monitor resistance variation as a sign of gas concentration. This miniature graphene-based gas sensor array demonstrates a new path for the use of graphene in gas-detection technologies. And the creation of a sensitive and portable graphene gas sensor also shows great potential in fields such as medicine and environmental science.
2016年04期 v.21 435-441页 [查看摘要][在线阅读][下载 713K] [下载次数：30 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：0 ] - Changqing Yin;Yuxing Li;Jiabin Wang;Xuefeng Wang;Yi Yang;Tian-Ling Ren;
Short-Term Memory(STM) is a primary capability of the human brain. Humans use STM to remember a small amount of information, like someone's phone number, for a short period of time. Usually the duration of STM is less than 1 minute. Synapses, the connections between neurons, are of vital importance to memory in biological brains. For mimicking the memory function of synapses, Carbon Nanotube(CNT) networks based thinfilm transistors with Electric Double Layers(EDL) at the dielectric/channel interface were researched in this work.A response characteristic of pre-synaptic potential pulses on the gate electrode of this CNT synaptic transistor was shown remarkably similar to Excitatory Post-Synaptic Current(EPSC) of biological synapses. Also a multi-level modulatable STM of CNT synaptic transistors was investigated. Post-synaptic current was shown with tunable peak values, on-off ratio, and relaxation time.
2016年04期 v.21 442-448页 [查看摘要][在线阅读][下载 348K] [下载次数：25 ] |[网刊下载次数：0 ] |[引用频次：3 ] |[阅读次数：0 ] - Rui Wang;Shilong Lu;Qingjuan Li;Lei Xu;Fei Chang;
Nowadays, with improvements in the quality of life, people are paying more attention to their health.Traditional Chinese medicine offers great advantages for daily care. In this paper, we present the development of a remote health care system, namely, Chinese Pulse Condition Acquisition System(CPCAS), based on the principle of Chinese pulse diagnosis in Chinese medicine and a wireless sensor network. We designed a remote health care terminal with a mini-pulse collection bench to overcome the challenge of differences in pulse characters of different people. An effective measured pressure control algorithm is proposed to achieve a balance between control accuracy and control time. The special signal conditioning circuit showed good performance in analog pulse signal processing. We also performed significant research to address the challenges of symptom recognition. Other distinctive features of this system include the following: intelligent sensing, a wireless health care network, effective energy management, small size, lightweight, and the ability to be networked for remote management. In this paper,we have introduced the design and implementation of CPCAS. We also demonstrate the use of the system and give evaluations on this system by several experiments. Our results indicate that CPCAS has significant practical feasibility.
2016年04期 v.21 449-458页 [查看摘要][在线阅读][下载 407K] [下载次数：65 ] |[网刊下载次数：0 ] |[引用频次：2 ] |[阅读次数：0 ] - Danfeng Wu;Guangping Zeng;Di He;Zhaopeng Qian;Qingchuan Zhang;
At present, robot embedded systems have some common problems such as closure and poor dynamic evolution. Aiming at resolving this situation, our paper focuses on improvements to the robot embedded system and sets up a new robot system architecture, and we propose a syncretic mechanism of a robot and Soft Man(SM). In the syncretic system, the structural organization of the Soft Man group and its modes are particularly important in establishing the task coordination mechanism. This paper, therefore, proposes a coordination organization model based on the Soft Man group, and studies in detail the process of task allocation for resource contention, which facilitates a rational allocation of system resources. During our research, we introduced Resource Requirement Length Algorithm(RRLA) to calculate the resource requirements of the task and a resource conformity degree allocation algorithm of Resource Conformity Degree Algorithm(RCDA) for resource contention. Finally, a comparative evaluation of RCDA with five other frequently used task allocation algorithms shows that RCDA has higher success and accuracy rates with good stability and reliability.
2016年04期 v.21 459-470页 [查看摘要][在线阅读][下载 404K] [下载次数：25 ] |[网刊下载次数：0 ] |[引用频次：2 ] |[阅读次数：0 ]