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  • Hindawi Limited  (6)
  • 1
    Online Resource
    Online Resource
    E2PP: An Energy-Efficient Path Planning Method for UAV-Assisted Data Collection
    Hindawi Limited ; 2020
    In:  Security and Communication Networks Vol. 2020 ( 2020-11-30), p. 1-13
    Details
    In: Security and Communication Networks, Hindawi Limited, Vol. 2020 ( 2020-11-30), p. 1-13
    Abstract: Using an unmanned aerial vehicle (UAV) to collect data from wireless sensor networks deployed in the field, one of the key tasks is to plan the path for the collection so as to minimize the energy consumption of the UAV. At present, most of the existing methods generally take the shortest flight distance as the optimal objective to plan the optimal path. They simply believe that the shortest path means the least energy consumption of the UAV and ignore the fact that changing direction (heading) can also consume the UAV’s energy in its flight. If the path can be planned based on the UAV’s energy consumption closer to the real situation, the energy consumption of the UAV can be really reduced and its working energy efficiency can be improved. Therefore, this paper proposes a path planning method for UAV-assisted data collection, which can plan an energy-efficient flight path. Firstly, by analyzing the experiment data, we, respectively, model the relationship between the angle of heading change and the energy consumption of the UAV and the relationship between the distance of straight flight and the energy consumption of the UAV. Then, an energy consumption estimation model based on distance and the angle of heading change (ECEMBDA) is put up. By using this model, we can estimate or predict the energy consumption of a UAV to fly from one point (or node) to another (including the start point). Finally, the greedy algorithm is used to plan the path for UAV-assisted data collection according to the above estimated energy consumption. Through simulation and experiments, we compare our proposed method with the conventional method based on pure distance index and greedy algorithm. The results show that this method can obtain data collection path with lower energy consumption and smoother path trajectory, which is more suitable for actual flight.
    Type of Medium: Online Resource
    ISSN: 1939-0122 , 1939-0114
    URL: Article
    DOI: 10.1155/2020/8850505
    Language: English
    Publisher: Hindawi Limited
    Publication Date: 2020
    detail.hit.zdb_id: 2415104-X
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  • 2
    Online Resource
    Online Resource
    Exploiting Wireless Received Signal Strength Indicators to Detect Evil-Twin Attacks in Smart Homes
    Hindawi Limited ; 2017
    In:  Mobile Information Systems Vol. 2017 ( 2017), p. 1-14
    Details
    In: Mobile Information Systems, Hindawi Limited, Vol. 2017 ( 2017), p. 1-14
    Abstract: Evil-Twin is becoming a common attack in smart home environments where an attacker can set up a fake AP to compromise the security of the connected devices. To identify the fake APs, The current approaches of detecting Evil-Twin attacks all rely on information such as SSIDs, the MAC address of the genuine AP, or network traffic patterns. However, such information can be faked by the attacker, often leading to low detection rates and weak protection. This paper presents a novel Evil-Twin attack detection method based on the received signal strength indicator (RSSI). Our approach considers the RSSI as a fingerprint of APs and uses the fingerprint of the genuine AP to identify fake ones. We provide two schemes to detect a fake AP in two different scenarios where the genuine AP can be located at either a single or multiple locations in the property, by exploiting the multipath effect of the Wi-Fi signal. As a departure from prior work, our approach does not rely on any professional measurement devices. Experimental results show that our approach can successfully detect 90% of the fake APs, at the cost of a one-off, modest connection delay.
    Type of Medium: Online Resource
    ISSN: 1574-017X , 1875-905X
    URL: Article
    DOI: 10.1155/2017/1248578
    RVK:
    QA 10000
    Language: English
    Publisher: Hindawi Limited
    Publication Date: 2017
    detail.hit.zdb_id: 2187808-0
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  • 3
    Online Resource
    Online Resource
    Improvement of Flavonoids in Lemon Seeds on Oxidative Damage of Human Embryonic Kidney 293T Cells Induced by H 2 O 2
    Hindawi Limited ; 2020
    In:  Oxidative Medicine and Cellular Longevity Vol. 2020 ( 2020-04-20), p. 1-10
    Details
    In: Oxidative Medicine and Cellular Longevity, Hindawi Limited, Vol. 2020 ( 2020-04-20), p. 1-10
    Abstract: In this study, flavonoids in lemon seeds (FLS) were used to assess its improvement on the oxidative damage of human embryonic kidney 293T cells (HEK 293T cells) induced by H 2 O 2 . In vitro experiments showed that the survival rates of HEK 293T cells treated with different flavonoid concentrations (50  μ g/mL, 100  μ g/mL, and 150  μ g/mL) exceeded 95%, indicating no significant toxic effect. Compared with the normal group, H 2 O 2 (0.3 mmol/L) resulted significantly in oxidative stress injury of HEK 293T cells. The survival rate of the damaged cells increased after treatment with flavonoids, and the survival rate of cells treated with a high concentration (150  μ g/mL) of flavonoids was 76.2%. Flavonoids also effectively inhibited H 2 O 2 -induced apoptosis. At the same time, flavonoid treatment significantly reduced the malondialdehyde content in cells and increased the levels of catalase (CAT), superoxide dismutase (SOD), glutathione (GSH), and glutathione peroxidase (GSH-Px). Quantitative polymerase chain reaction (qPCR) and Western blot analysis also suggested that FLS upregulated mRNA and protein expressions of CAT, SOD (SOD1, SOD2), GSH (GSH1), and GSH-Px in H 2 O 2 -induced oxidative damage of HEK 293T cells. The high-performance liquid chromatography analysis demonstrated that FLS contained six compounds, including gallocatechin, caffeic acid, epicatechin, vitexin, quercetin, and hesperidin. FLS were proven to have a good antioxidant capacity in vitro and improve significantly the oxidative damage of HEK 293T cells induced by H 2 O 2 . The biological activity value warrants investigation in additional studies.
    Type of Medium: Online Resource
    ISSN: 1942-0900 , 1942-0994
    URL: Article
    DOI: 10.1155/2020/3483519
    Language: English
    Publisher: Hindawi Limited
    Publication Date: 2020
    detail.hit.zdb_id: 2455981-7
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  • 4
    Online Resource
    Online Resource
    Tubeimoside I Ameliorates Myocardial Ischemia-Reperfusion Injury through SIRT3-Dependent Regulation of Oxidative Stress and Apoptosis
    Hindawi Limited ; 2021
    In:  Oxidative Medicine and Cellular Longevity Vol. 2021 ( 2021-11-9), p. 1-22
    Details
    In: Oxidative Medicine and Cellular Longevity, Hindawi Limited, Vol. 2021 ( 2021-11-9), p. 1-22
    Abstract: Myocardial ischemia-reperfusion injury (MIRI) is a phenomenon that reperfusion leads to irreversible damage to the myocardium and increases mortality in acute myocardial infarction (AMI) patients. There is no effective drug to treat MIRI. Tubeimoside I (TBM) is a triterpenoid saponin purified from Chinese traditional medicine tubeimu. In this study, 4 mg/kg TBM was given to mice intraperitoneally at 15 min after ischemia. And TBM treatment improved postischemic cardiac function, decreased infarct size, diminished lactate dehydrogenase release, ameliorated oxidative stress, and reduced apoptotic index. Notably, ischemia-reperfusion induced a significant decrease in cardiac SIRT3 expression and activity, while TBM treatment upregulated SIRT3’s expression and activity. However, the cardioprotective effects of TBM were largely abolished by a SIRT3 inhibitor 3-(1H-1,2,3-triazol-4-yl) pyridine (3-TYP). This suggests that SIRT3 plays an essential role in TBM’s cardioprotective effects. In vitro, TBM also protected H9c2 cells against simulated ischemia/reperfusion (SIR) injury by attenuating oxidative stress and apoptosis, and siSIRT3 diminished its protective effects. Taken together, our results demonstrate for the first time that TBM protects against MIRI through SIRT3-dependent regulation of oxidative stress and apoptosis. TBM might be a potential drug candidate for MIRI treatment.
    Type of Medium: Online Resource
    ISSN: 1942-0994 , 1942-0900
    URL: Article
    DOI: 10.1155/2021/5577019
    Language: English
    Publisher: Hindawi Limited
    Publication Date: 2021
    detail.hit.zdb_id: 2455981-7
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  • 5
    Online Resource
    Online Resource
    Experimental study of the moisture content influence on CH 4 adsorption and deformation characteristics of cylindrical bituminous coal core
    Hindawi Limited ; 2018
    In:  Adsorption Science & Technology Vol. 36, No. 7-8 ( 2018-10), p. 1512-1537
    Details
    In: Adsorption Science & Technology, Hindawi Limited, Vol. 36, No. 7-8 ( 2018-10), p. 1512-1537
    Abstract: Moisture content in coal is an important factor affecting the coal seam gas extraction. It directly affects the storage and flow of gas in bituminous coal. In this paper, the cylindrical bituminous coal cores of Xutuan coal mine in Huaibei coal mine group were studied as experimental objects, using the laboratory self-designed experimental device Gas Adsorption and Strain Testing Apparatus system. The influence of the bituminous coal moisture content on gas adsorption characteristics was studied. Drying experiments of coal samples showed that they lose the original moisture content following the exponential decay function of time. At wetting, the saturated moisture content in coal samples increased following the Exponential Association function of time. The experimental results show that the average original moisture content and average saturated moisture content of raw coal samples are 1.3 and 2.4%, respectively. On this basis, the gas adsorption experiments on samples with different moisture contents under different gas pressures were carried out. With the moisture content increase, the gas adsorption capacity and saturation value decreased and the decrease rate gradually reduced. The single exponential decay function describes the gas adsorption capacity dependence on moisture content. Moisture content also affects the adsorption deformation of bituminous coal. At high moisture content, the adsorption deformation of bituminous coal is less.
    Type of Medium: Online Resource
    ISSN: 0263-6174 , 2048-4038
    URL: Article
    DOI: 10.1177/0263617418788444
    RVK:
    VA 1500
    Language: English
    Publisher: Hindawi Limited
    Publication Date: 2018
    detail.hit.zdb_id: 2017917-0
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  • 6
    Online Resource
    Online Resource
    GuideLoc: UAV-Assisted Multitarget Localization System for Disaster Rescue
    Hindawi Limited ; 2017
    In:  Mobile Information Systems Vol. 2017 ( 2017), p. 1-13
    Details
    In: Mobile Information Systems, Hindawi Limited, Vol. 2017 ( 2017), p. 1-13
    Abstract: Locating trapped targets using the signals of wireless devices such as mobile phones carried by targets is increasingly becoming the preferred scheme for disaster rescue. However, the accuracy of radio-localization technology currently adopted in the rescue is not high enough. To solve such problems, researchers proposed the approaches of Warwalking or Wardriving. However, both approaches are all limited by application scenarios. This paper proposes GuideLoc, a highly efficient aerial wireless localization system, which uses the target guiding technology based on region division. GuideLoc allows an unmanned aerial vehicle (UAV) to fly over a target device and provide position coordinates of the UAV as the target location information. During the process of positioning targets, based on the result of regional division, GuideLoc uses a number of fixed antennas to get the received signal strength indicator (RSSI) and angle of arrival (AOA) information of the target and estimates the target location using the information and correspondingly controls the UAV to fly towards the target. Averaging method is also applied for determining coordinates of the target. Experiment results show that GuideLoc can in short time achieve 2.7-meter positioning accuracy in average. Compared with other wireless localization methods using UAVs proposed in the literature, it shortened the flight distance by more than 50%. In addition, energy efficiency is also improved significantly.
    Type of Medium: Online Resource
    ISSN: 1574-017X , 1875-905X
    URL: Article
    DOI: 10.1155/2017/1267608
    RVK:
    QA 10000
    Language: English
    Publisher: Hindawi Limited
    Publication Date: 2017
    detail.hit.zdb_id: 2187808-0
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