Adaptive Application Component Mapping for Parallel Computation Offloading in Variable Environments

( Wenhao Fan ),( Yuan`an Liu ),( Bihua Tang ) 한국인터넷정보학회 2015 KSII Transactions on Internet and Information Syst Vol.9 No.11

Distinguished with traditional strategies which offload an application`s computation to a single server, parallel computation offloading can promote the performance by simultaneously delivering the computation to multiple computing resources around the mobile terminal. However, due to the variability of communication and computation environments, static application component multi-partitioning algorithms are difficult to maintain the optimality of their solutions in time-varying scenarios, whereas, over-frequent algorithm executions triggered by changes of environments may bring excessive algorithm costs. To this end, an adaptive application component mapping algorithm for parallel computation offloading in variable environments is proposed in this paper, which aims at minimizing computation costs and inter-resource communication costs. It can provide the terminal a suitable solution for the current environment with a low incremental algorithm cost. We represent the application component multi-partitioning problem as a graph mapping model, then convert it into a pathfinding problem. A genetic algorithm enhanced by an elite-based immigrants mechanism is designed to obtain the solution adaptively, which can dynamically adjust the precision of the solution and boost the searching speed as transmission and processing speeds change. Simulation results demonstrate that our algorithm can promote the performance efficiently, and it is superior to the traditional approaches under variable environments to a large extent.

Energy Efficient Traffic Allocation for Resource-constrained Multi-homed WSN Gateway

Wenhao Fan,Bihua Tang,Yuan’an Liu 보안공학연구지원센터 2015 International Journal of Smart Home Vol.9 No.10

WSN (Wireless Sensor Network) gateway acts as a bridge between WSN and external networks. Currently, rapid growing demands from various IoTs (Internet of Things) applications are posing critical challenges to the data transmission capability of such gateway. As a promising solution, multi-homed WSN gateway, which is equipped with multiple network interfaces, can obtain enhanced parallel data transmission by jointly utilizing multiple RATs (Radio Access Technologies). However, the multi-homed gateway is a resource-constrained device, so it’s crucial to guarantee the efficiency for both data throughput and resource consumption. Delay and buffer size, simulation results validate that the proposed algorithm can allocate To this end, an energy efficient traffic allocation algorithm for resource-constrained multi-homed WSN gateway is proposed in this paper, which aims at minimizing the gateway's power consumption while guaranteeing the transmission the traffic optimally for the gateway with different constraints and configurations, and it can significantly promote the gateway's energy efficiency in comparison to the traditional method.

A New Triterpenoid Saponin from Pulsatilla cernua

Wenhao Fan,Yongnan Xu,Jianyu Liu,Yixia Gong,Jing Ma,Nan Zhou 한국생약학회 2013 Natural Product Sciences Vol.19 No.2

A new oleanane-type triterpenoid saponin together with six known saponins were isolated from the roots of Pulsatilla cernua. Their structures were elucidated on the basis of spectroscopic data, including 2D NMR spectra and chemical evidence. Compounds 1 and 6 are reported from this genus for the first time.

Application Multi-partitioning for Offloading Computation to Multiple Computing Resources around Mobile Terminals

Wenhao Fan,Bihua Tang,Yuan’an Liu 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.6

Different with traditional approaches that offload computation to a single remote server, the performance of an application can be further enhanced by simultaneously distributing its computing tasks to multiple computing resources around the mobile terminal. How to effectively multiply partition application components is critical for parallel computation offloading. In this paper, an application multi-partitioning scheme is proposed, which optimally offloads application's components to surrounding resources. A graph mapping model is converted and set up to represent components and resources as undirected graphs, and the A* algorithm is employed to efficiently search the optimal mapping from component graph to resource graph, which minimizes computing costs and inter-resource communication costs. Simulation results demonstrate that the performance can be efficiently promoted by our algorithm, which outperforms the traditional approaches to a large degree.

An API Calls Monitoring-based Method for Effectively Detecting Malicious Repackaged Applications

Wenhao Fan,Yuan’an Liu,Bihua Tang 보안공학연구지원센터 2015 International Journal of Security and Its Applicat Vol.9 No.8

The number of mobile applications on Android platform has largely increased in recent years. The security problems, as one of the outcomes induced by the popularity of Android, become more and more critical. Malicious repackaged applications (MRAs) perform malicious behaviors through malware developers embedding malicious codes into the benign origin applications (BOAs), which threat the security of users’ finance and privacy. In this paper, a method based on API calls monitoring is proposed to effectively detect MRAs. We discuss the characteristics of behaviors and analyze the differences in API calls between MRAs and their BOAs. A MRA detection model is established, which builds up the super-sphere for each BOA via a SVDD algorithm. The model can detect the abnormal behaviors of MRAs which deviate the normal behaviors of corresponding BOAs. Experiments are carried out on imitated and real MRAs, where the results demonstrate the effectiveness of our method for detecting the singly and multiply contaminated BOAs.

Investigation on characteristics of pulverized coal dense-phase pneumatic conveying under high pressure

Chen Xiaoping,Fan Chunlei,Liang Cai,Pu Wenhao,Lu Peng,Zhao Changsui 한국화학공학회 2007 Korean Journal of Chemical Engineering Vol.24 No.3

of dense-phase pneumatic conveying of pulverized coal were carried out in a test facility witha conveying pressure up to 4 MPa. The influence of fluidization nitrogen flow rate, the flow rate of supplementarysolid mass flow rate was investigated. Test results indicate that with the increase in fluidization nitrogen flow rate, thesolid mass flow rate increases, and the solids to gas ratio increases at first and then declines. When the fluidization ofpulverized coal in the sending vessel becomes intensive, with the increase in supplementary nitrogen flow rate, thesolids to gas ratio declines and the solid mas flow rate increases. And the solid mass flow rate increases linearly withthe increase in presure diference between two hoppers. The experimental results provide a database for the design

A New Combined Support Technology to Prevent the Failure of the Existing Metro Station Induced by Unilateral Excavation

Feicong Zhou,Wenhao Fan,Ping Zhou,Mao Chen,Shougen Chen,Zhijie Wang,Yifan Jiang 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.3

This study establishes a 3-D simulation model based on a real project, which reveals the problem that the metro structure deformation induced by unilateral excavation without any support exceeds the safety threshold. According to the metro structure deformation warning area, this study proposes a support technology that combines cover plate braces and diagonal steel braces. The research shows that the lateral deformation reduction ratio of the metro station under the diagonal steel brace is about 10% − 20%. The deformation reduction ratio under the cover plate brace is about 35% − 40%. To ensure construction safety, this study adopts the optimal support combination of 3 cover plates and 6+9+11 steel pipes. Monitoring feedback and simulation prediction shows that the comprehensive support system can reduce structural deformation by 56.1%, and effectively control the deformation within a safe range.

The Effect of Obstacle Number, Shape and Blockage Degree in Flow Field of PEMFC on its Performance

Zongxi Zhang,Xiang Fan,Wenhao Lu,Jian Yao,Zhike Sui The Korean Electrochemical Society 2024 Journal of electrochemical science and technology Vol.15 No.1

Proton exchange membrane fuel cell (PEMFC) has received extensive attention as it is the most common hydrogen energy utilization device. This research not only investigated the effect of obstacle number and shape on PEMFC performance, but also studied the effect of the blockage degree in the channel of PEMFC on its performance. It was found that compared with traditional scheme, longitudinally distributed obstacles scheme can significantly promote reactants transfer to catalyst layer, and the blockage degree in the channel effect PEMFC performance most. The scheme with 10 rectangular obstacles in single channel and 60% channel blockage had the best output performance and the most uniform distribution of reactants and products. Obstacle height distribution can significantly affect PEMFC performance, the blockage degree in the whole basin was large, particularly as the channel was blocked to higher degree in region 2 and region 3, higher net power density and better mass transfer effect can be obtained. Among them, the fuel cell with the blockage degree of 40%, 60% and 60% in region 1, region 2 and region 3 have the best PEMFC output performance and mass transfer, the net power density was 29.8% higher than that of traditional scheme.

A Throughput Improved Path Selection Method Based on Throughput Prediction Model and Available Bandwidth for MPTCP

Xiaomin Jin,Yuanan Liu,Wenhao Fan,Fan Wu,Hongguang Zhang 보안공학연구지원센터 2015 International Journal of Future Generation Communi Vol.8 No.2

Nowadays, many network devices have more than one network interface. Meanwhile, many protocols have been proposed to utilize multiple paths simultaneously. MPTCP (Multipath TCP) is a transport layer protocol that transfers data by multiple paths simultaneously, which is designed to improve the throughput and increase robustness of end to end transmission. However, when we use MPTCP, we find that MPTCP can not improve the throughput but even reduce the throughput in some cases. In this paper, we study this issue. Firstly, we study the effects of path characteristics for throughput of MPTCP, and find that path characteristics especially those bad paths have a great impact on the performance of MPTCP. Secondly, we analyze the reasons why the bad path characteristics have a serious impact on throughput of MPTCP, and propose a path selection method based on throughput prediction model and available bandwidth to improve the throughput. Finally, we validate our path selection method by simulations, and the results show that our method can improve the throughput of MPTCP.

Flow characteristics and dynamic behavior of dense-phase pneumatic conveying of pulverized coal with variable moisture content at high pressure

Liang Cai,Chen Xiaoping,Zhao Changsui,Pu Wenhao,Lu Peng,Fan Chunlei 한국화학공학회 2009 Korean Journal of Chemical Engineering Vol.26 No.3

Experiments of dense-phase pneumatic conveying of pulverized coal using nitrogen were performed in an experimental test facility with the conveying pressure up to 4MPa and the solid-gas ratio up to 500 kg/㎥. The influences of the total conveying differential pressure, the moisture content, the superficial velocity and the pressure on the mass flow rate and the solid-gas ratio were investigated. Shannon entropy analysis of pressure fluctuation time series was developed to reveal the flow characteristics. Based on the distribution of the Shannon entropy in the different conditions, the flow stability and the evolutional tendency of Shannon entropy in different regimes and the regime transition processes were obtained. The results indicate that the solid gas ratio and Shannon entropy rise with increase in the total conveying differential pressure. A phase diagram and Shannon entropy reveal preferable regularity with superficial velocity. Shannon entropy is different for the different flow regimes, and it can be used to identify the flow regimes. As the moisture content increases, the mass flow rate, the pressure drop and Shannon entropy decrease. Shannon entropy rises with increase in pressure drop.