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Short-Term Forecasting for Harbor Waterway Currents Speeds
Cheng Gong,Yan Lv,Chunjiang Zhang,Xiyuan Wang,Wei Huangfu,Zhongshan Zhang 보안공학연구지원센터 2014 International Journal of Multimedia and Ubiquitous Vol.9 No.12
The ocean currents speeds in the harbor waterway are directly related to the ability of the ship to in or out the harbor. Accurately predict the speeds can assist the ship to choose the right time for sailing. To solve this problem, we chose two models of linear and non-linear prediction. We had set sensors in Qinhuangdao for a long time, then using the collected data for training. Our test is using a lot of random data to train and predict with different steps and orders. The results show that both methods can use less original data to train the model, and finally achieve preferably prediction. According to the characteristics of Qinhuangdao harbor, Auto-Regressive (AR) model is more appropriate than Support Vector Regression (SVR) model.
Nematicidal effect of volatiles produced by Trichoderma sp.
Zhongshan Yang,ZeFen Yu,,Liping Lei,Zhenyuan Xia,Li Shao,Ke Qin Zhang,Guo Hong Li 한국응용곤충학회 2012 Journal of Asia-Pacific Entomology Vol.15 No.4
Trichoderma is an important biocontrol agent that produces metabolites harmful to nematodes. We investigated the volatile organic compounds (VOCs) of Trichoderma sp. YMF 1.00416 and examined their abilities to kill nematodes. Chemical investigations of the VOCs from this strain led to the isolation and identification of three metabolites: a new compound, 1β-vinylcyclopentane-1α,3α-diol (1) and two known metabolites, 6-pentyl-2H-pyran-2-one (2) and 4-(2-hydroxyethyl)phenol (3). Nematicidal activity assays showed that compound 2 was nematicidal, and killed >85% of Panagrellus redivivus, Caenorhabditis elegans,and Bursaphelenchus xylophilus in 48 h at 200 mg/L in a 2 mL vial. Our results will help identify new nematicides.
( Bin Zhong ),( Zhongshan Zhang ),( Dandan Zhang ),( Keping Long ),( Haiyan Cao ) 한국인터넷정보학회 2014 KSII Transactions on Internet and Information Syst Vol.8 No.11
The performance of an partial relay selection on the decode-and-forward (DF) mode cognitive radio (CR) relay networks is studied, with some important factors, including the outage probability, the bit error ratio (BER), and the average channel capacity being analyzed. Different from the conventional relay selection schemes, the impact of spectrum sensing process as well as the spectrum utilization efficiency of primary users on the performance of DF-based CR relaying networks has been taken into consideration. In particular, the exact closed-form expressions for the figures of merit such as outage probability, BER, and average channel capacity over independent and identically distributed (i.i.d.) Rayleigh fading channels, have been derived in this paper. The validity of the proposed analysis is proven by simulation, which showed that the numerical results are consistent with the theoretical analysis in terms of the outage probability, the BER and the average channel capacity. It is also shown that the full spatial diversity order can always be obtained at the signal-to-noise ratio (SNR) range of [0dB, 15dB] in the presence of multiple potential relays.
Nematicidal coumarin from Ficus carica L.
Fangfang Liu,Zhongshan Yang,Xi Zheng,Shaoliu Luo,Ke Qin Zhang,Guo Hong Li 한국응용곤충학회 2011 Journal of Asia-Pacific Entomology Vol.14 No.1
The methanol extracts from 40 plant species were screened for their nematicidal activity against the nematodes Bursaphelenchus xylophilus, Panagrellus redivivus and Caenorhabditis elegans. The leaf extract of Ficus carica L. exhibited the strongest nematicidal activity, causing 74.3%, 96.2% and 98.4% mortality,respectively, within 72 h. By bioassay-guided fractionation, a coumarin was obtained. The compound was determined to be psoralen based on spectroscopic data. It showed nematicidal activity against the tested nematodes. This is the first report of the nematicidal activity of F. carica and psoralen.
( Qian Zeng ),( Zhongshan Zhang ) 한국인터넷정보학회 2019 KSII Transactions on Internet and Information Syst Vol.13 No.4
Unmanned aerial vehicles (UAVs), acting as mobile base stations (BSs), can be deployed in the typical fifth-generation mobile communications (5G) scenarios for the purpose of substantially enhancing the radio coverage. Meanwhile, UAV aided underlay device-to-device (D2D) communication mode can be activated for further improving the capacity of the 5G networks. However, this UAV aided D2D communication system is more vulnerable to eavesdropping attacks, resulting in security risks. In this paper, the D2D receivers work in full-duplex (FD) mode, which improves the security of the network by enabling these legitimate users to receive their useful information and transmit jamming signal to the eavesdropper simultaneously (with the same frequency band). The security communication under the UAV coverage is evaluated, showing that the system’s (security) capacity can be substantially improved by taking advantage of the flexible radio coverage of UAVs. Furthermore, the closed-form expressions for the coverage probabilities are derived, showing that the cellular users (CUs)’ secure coverage probability in downlink transmission is mainly impacted by the following three factors: its communication area, the relative position with UAV, and its eavesdroppers. In addition, it is observed that the D2D users or DUs’ secure coverage probability is relevant to state of the UAV. The system’s secure capacity can be substantially improved by adaptively changing the UAV’s position as well as coverage.
Power Allocation for Opportunistic Full-Duplex based Relay Selection in Cooperative Systems
( Bin Zhong ),( Dandan Zhang ),( Zhongshan Zhang ) 한국인터넷정보학회 2015 KSII Transactions on Internet and Information Syst Vol.9 No.10
In this paper, performance analysis of full-duplex (FD) relay selection under decode-and-forward (DF) relaying mode is carried out by taking into account several critical factors, including the distributions of the received signal-to-noise ratio (SNR) and the outage probability of wireless links. The tradeoff between the FD and half-duplex (HD) modes for relay selection techniques is also analyzed, where the former suffers from the impact of residual self-interference, but the latter requires more channel resources than the former (i.e., two orthogonal channels are required). Furthermore, the impact of optimal power allocation (OPA) on the proposed relay-selection scheme is analyzed. Particularly, the exact closed-form expressions for outage probability of the proposed scheme over Rayleigh fading channels are derived, followed by validating the proposed analysis using simulation. Numerical results show that the proposed FD based scheme outperforms the HD based scheme by more than 4 dB in terms of coding gain, provided that the residual self-interference level in the FD mode can be substantially suppressed to the level that is below the noise power.
A Survey of Self-optimization Approaches for HetNets
( Xiaomeng Chai ),( Xu Xu ),( Zhongshan Zhang ) 한국인터넷정보학회 2015 KSII Transactions on Internet and Information Syst Vol.9 No.6
Network convergence is regarded as the development tendency of the future wireless networks, for which self-organization paradigms provide a promising solution to alleviate the upgrading capital expenditures (CAPEX) and operating expenditures (OPEX). Self-optimization, as a critical functionality of self-organization, employs a decentralized paradigm to dynamically adapt the varying environmental circumstances while without relying on centralized control or human intervention. In this paper, we present comprehensive surveys of heterogeneous networks (HetNets) and investigate the enhanced self-optimization models. Self-optimization approaches such as dynamic mobile access network selection, spectrum resource allocation and power control for HetNets, etc., are surveyed and compared, with possible methodologies to achieve self-optimization summarized. We hope this survey paper can provide the insight and the roadmap for future research efforts in the self-optimization of convergence networks.
( Xianxian Wang ),( Shaobo Lv ),( Xing Wang ),( Zhongshan Zhang ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.4
Resource allocation in device-to-device (D2D) aided cellular systems, in which the proximity users are allowed to communicate directly with each other without relying on the intervention of base stations (BSs), is investigated in this paper. A new uplink resource allocation policy is proposed by exploiting the relationship between D2D-access probability and channel gain among variant devices, such as cellular user equipments (CUEs), D2D user equipments (DUEs) and BSs, etc., under the constraints of their minimum signal to interference-plus-noise ratio (SINR) requirements. Furthermore, the proposed resource-allocation problem can be formulated as the cost function of “maximizing the number of simultaneously activated D2D pairs subject to the SINR constraints at both CUEs and DUEs”. Numerical results relying on system-level simulations show that the proposed scheme is capable of substantially improving both the D2D-access probability and the network throughput without sacrificing the performance of conventional CUEs.