141 research outputs found

    Neural network based patient recovery estimation of a PAM-based rehabilitation robot

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    Rehabilitation robots have shown a promise in aiding patient recovery by supporting them in repetitive, systematic training sessions. A critical factor in the success of such training is the patient’s recovery progress, which can guide suitable treatment plans and reduce recovery time. In this study, a neural network-based approach is proposed to estimate the patient’s recovery, which can aid in the development of an assist-as-needed training strategy for the gait training system. Experimental results show that the proposed method can accurately estimate the external torques generated by the patient to determine their recovery. The estimated patient recovery is used for an impedance control of a 2-DOF robotic orthosis powered by pneumatic artificial muscles, which improves the robot joint compliance coefficients and makes the patient more comfortable and confident during rehabilitation exercises

    SWIPT-enabled cooperative wireless IoT networks with friendly jammer and eavesdropper: Outage and intercept probability analysis

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    Physical layer security (PLS) and simultaneous wireless information and power transfer (SWIPT) in cooperative relaying have gained great interest as technologies for security and energy enhance ment in Internet-of-Things (IoT) networks. In this work, we investigate PLS for a SWIPT- and AF-enabled cooperative wireless IoT system, consisting of one source, multiple energy harvesting (EH) relays, and one destination, in the presence of an eavesdropper that tries to overhear the confidential information. Furthermore, an EH-friendly jammer is deployed to transmit jamming signals aimed at the eavesdropper to improve the security system. In this context, a low-complexity, sub-optimal, but efficient relay selection method is proposed. More specifically, the relay is selected to convey information such that it has the best channel to the source. Based on the proposed system model, the performance analysis of the intercept probability (IP), asymptotic IP, and non-zero secrecy probability (NZSP) is analyzed by considering the time switching (TS)-based relaying strategy. Particularly, the exact closed-form expression of IP is achieved by applying modified Bessel function expansion. Monte-Carlo simulations are employed to corroborate the correctness and efficiency of our mathematical analysis. The time splitting factor α makes variations on the IP of about 3× as α ∈ [0.1, 0.8]. However, a dramatic reduction of the IP up to 317× is observed as α increases from 0.8 to 0.9.Web of Science11861778616

    Security and Reliability Analysis of Satellite-Terrestrial Multi-Relay Networks with Imperfect CSI

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    This work investigates the security and reliabil- ity analysis for a novel satellite-terrestrial (SatTer) network. Specifically, a satellite attempts to transmit confidential infor- mation to a ground user (GU) via the support of multiple relay nodes in the presence of an eavesdropper that tries to overhear the information. A friendly jammer is deployed to improve the secure transmission between the satellite and the relays. Furthermore, satellite-to-relay generalized Rician fading channels and imperfect channel state information (CSI) are deployed to examine a general system model. In this context, the closed-formed expressions for the outage probability (OP) and intercept probability (IP) are derived corresponding to an amplify-and-forward (AF)-based relaying scheme, which is challenging and has not been studied before. Finally, the exactness of the mathematical analyses is validated through Monte Carlo simulations. Furthermore, the effects of various key parameters (e.g., channel estimation errors, satellite’s transmit power, relay’s transmit power, number of relays, and fading severity parameter) are examine

    Rapid beam training at terahertz frequency with contextual multi-armed bandit learning

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    Terahertz (THz) frequency technology holds great promise for enabling high data rates and low latency, essential for manufacturing applications within Industry 4.0. To achieve these, beam training is necessary to enable MIMO communications without the need for explicit channel state information (CSI). In this context, the Multi-Armed Bandit (MAB) algorithms are able to facilitate online learning and decision-making in beam training, eliminating the necessity for extensive offline training and data collection. In this paper, we introduce three algorithms to investigate the applications of MAB in beam training at Terahertz frequency: UCB, Loc-LinUCB, and Probing-LinUCB. While UCB builds upon the well-established Upper Confidence Bound algorithm, Loc-LinUCB and Probing-LinUCB utilize the location of the user equipment (UE) and probing information to enhance decision-making, respectively. The beam training protocols for each algorithm are also detailed. We evaluate the performance of these algorithms using data generated by the DeepMIMO framework, which simulates abrupt changes and various challenging characteristics of wireless channels encountered in realistic scenarios as UEs move. The results illustrate that Loc-LinUCB and Probing-LinUCB outperform UCB, showing the potential of leveraging contextual MAB for beam training in Terahertz communications

    Security-Reliability Tradeoffs for Satellite-Terrestrial Relay Networks with a Friendly Jammer and Imperfect CSI

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    peer reviewedThis article proposes and analyzes the reliability and security tradeoff for a satellite-terrestrial (SatTer) relay system. Herein, a satellite sends confidential information to multiple ground users with the help of a relay base station (BS) in the presence of multiple eavesdroppers trying to wiretap the information. In particular, a friendly jammer is deployed near the relay BS to improve secure transmissions. Moreover, the nonidentical Rayleigh fading channels and imperfect channel state information are adopted for a general system model. Then, we consider both amplify-and-forward (AF) and decode-and-forward (DF) relaying strategies to give a full picture of the benefits of each method. In this context, we derive the closed-form expressions of the outage probability and intercept probability corresponding to AF- and DF-based relaying schemes, which is a high challenge and has not been investigated before. Then, Monte-Carlo simulations are conducted to evaluate the correctness of the mathematical analysis and the effectiveness of the proposed methods. Furthermore, the security and reliability trade-off of the SatTer system and the influences of various system parameters (e.g., satellite's transmit power, channel estimation errors, relay's transmit power, fading severity parameter, the average power of light-of-sight, and satellite's multipath components) on the system performance are shown

    Security–Reliability Tradeoff Analysis for SWIPT- and AF-Based IoT Networks With Friendly Jammers

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    Radio-frequency (RF) energy harvesting (EH) in wireless relaying networks has attracted considerable recent interest, especially for supplying energy to relay nodes in the Internet of Things (IoT) systems to assist the information exchange between a source and a destination. Moreover, limited hardware, computational resources, and energy availability of IoT devices have raised various security challenges. To this end, physical-layer security (PLS) has been proposed as an effective alternative to cryptographic methods for providing information security. In this study, we propose a PLS approach for simultaneous wireless information and power transfer (SWIPT)-based half-duplex (HD) amplify-and-forward (AF) relaying systems in the presence of an eavesdropper. Furthermore, we take into account both static power splitting relaying (SPSR) and dynamic power splitting relaying (DPSR) to thoroughly investigate the benefits of each one. To further enhance secure communication, we consider multiple friendly jammers to help prevent wiretapping attacks from the eavesdropper. More specifically, we provide a reliability and security analysis by deriving closed-form expressions of outage probability (OP) and intercept probability (IP), respectively, for both the SPSR and DPSR schemes. Then, simulations are also performed to validate our analysis and the effectiveness of the proposed schemes. Specifically, numerical results illustrate the nontrivial tradeoff between reliability and security of the proposed system. In addition, we conclude from the simulation results that the proposed DPSR scheme outperforms the SPSR-based scheme in terms of OP and IP under the influences of different parameters on system performance

    Potential application of rhizobacteria isolated from the Central Highland of Vietnam as an effective biocontrol agent of robusta coffee nematodes and as a bio-fertilizer

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    [[abstract]]Robusta coffee is a major commercial crop in the Central Highland of Vietnam with high economic and export value. However, this crop is adversely affected by various pathogens, particularly nematodes. This study aimed to screen active anti-nematode rhizobacterial strains for sustainable coffee production. Among more than 200 isolates, the isolate TUN03 demonstrated efficient biocontrol with nearly 100% mortality of J2 coffee nematodes Meloidogyne spp. and 84% inhibition of nematode egg hatching. This active strain was identified as Pseudomonas aeruginosa TUN03 based on its 16S rRNA gene sequence and phylogenetic analysis. In greenhouse tests, the strain TUN03 significantly reduced the coffee nematode population in the rhizome-soil with an 83.23% inhibition rate and showed plant growth-promoting effects. Notably, this is the first report of the nematicidal effect of P. aeruginosa against coffee nematodes. This potent strain further showed an antifungal effect against various crop-pathogenic fungi and was found to be the most effective against Fusarium solani F04 (isolated from coffee roots) with a 70.51% inhibition rate. In addition, high-performance liquid chromatography analysis revealed that this bacterial strain also secretes plant growth regulators including indole acetic acid (IAA), gibberellic acid (GA3), kinetin, and zeatin in significant amounts of 100, 2700, 37, and 9.5 µg/mL, respectively. The data from this study suggest that P. aeruginosa TUN03 may be a potential biocontrol agent and biofertilizer for the sustainable production of Robusta coffee and other crops.[[sponsorship]]科技部[[notice]]補正完

    Treatment incidence of and medical utilization for hospitalized subjects with pathologic fractures in Taiwan-Survey of the 2008 National Health Insurance data

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    <p>Abstract</p> <p>Background</p> <p>Almost all studies of pathologic fractures have been conducted based on patients with tumours and hospital-based data; however, in the present study, a nationwide epidemiological survey of pathologic fractures in Taiwan was performed and the medical utilization was calculated.</p> <p>Methods</p> <p>All claimants of Taiwan's National Health Insurance (NHI) Program in 2008 were included in the target population of this descriptive cross-sectional study. The registration and inpatient expenditure claims data by admission of all hospitalized subjects of the target population were examined and the concomitant International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) diagnosis codes were evaluated and classified into seven major categories of fracture.</p> <p>Results</p> <p>A total of 5,244 incident cases of pathologic fracture were identified from the 2008 hospitalized patient claims data. The incidence of pathologic fracture of the humerus, distal radius/ulna, vertebrae, femoral neck, other part of the femur, and tibia/fibula was 0.67, 0.08, 10.58, 1.11, 0.56, and 0.11 per 100,000 people, respectively, and patients with those fractures were hospitalized for 43.9 ± 42.9, 31.1 ± 32.9, 29. 4 ± 34.4, 43.3 ± 41.2, 42.4 ± 38.1, and 42.0 ± 32.8 days, respectively, incurring an average medical cost of US11,049±12,730,US11,049 ± 12,730, US9,181 ± 12,115, US6,250±8,021,US6,250 ± 8,021, US9,619 ± 8,906, US10,646±11,024,andUS10,646 ± 11,024, and US9,403 ± 9,882, respectively. The percentage of patients undergoing bone surgery for pathologic fracture of the humerus, radius/ulna, vertebrae, femoral neck, other part of the femur, and tibia/fibula was 31.2%, 44.4%, 11.3%, 46.5%, 48.4%, and 52.5% respectively.</p> <p>Conclusions</p> <p>Comparing Taiwan to other countries, this study observed for Taiwan higher medical utilization and less-aggressive surgical intervention for patients hospitalized with pathologic fractures.</p

    Epidemiological survey of orthopedic joint dislocations based on nationwide insurance data in Taiwan, 2000-2005

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    <p>Abstract</p> <p>Background</p> <p>The epidemiology of acute orthopedic dislocations is poorly understood. A nationwide database provides a valuable resource for examining this issue in the Taiwanese population.</p> <p>Methods</p> <p>A 6-year retrospective cohort study of 1,000,000 randomly-sampled beneficiaries from the year 2005 was used as the original population. Based on the hospitalized and ambulatory data, the concomitant ICD9-CM diagnosis codes and treatment codes were evaluated and classified into 8 and 3 major categories, respectively. The cases matching both inclusive criteria of dislocation-related diagnosis codes and treatment codes were defined as incident cases.</p> <p>Results</p> <p>During 2000-2005, the estimated annual incidence (per 100,000 population) of total orthopedic dislocations in Taiwan was 42.1 (95%CI: 38.1-46.1). The major cause of these orthopedic dislocations was traffic accidents (57.4%), followed by accident falls (27.5%). The annual incidence dislocation by location was shoulder, 15.3; elbow, 7.7; wrist, 3.5; finger, 4.6; hip, 5.2; knee, 1.4; ankle, 2.0; and foot, 2.4. Approximately 16% of shoulder dislocations occurred with other concomitant fractures, compared with 17%, 53%, 16%, 76% and 52%, respectively, of dislocated elbow, wrist, hip, knee, and ankle cases. Including both simple and complex dislocated cases, the mean medical cost was US612fortreatmentofashoulderdislocation,612 for treatment of a shoulder dislocation, 504 for the elbow, 1,232forthewrist,1,232 for the wrist, 1,103 for the hip, 1,888fortheknee,and1,888 for the knee, and 1,248 for the ankle.</p> <p>Conclusions</p> <p>In Taiwan, three-quarters of all orthopedic dislocations were of the upper limbs. The most common complex fracture-dislocation was of the knee, followed by the wrist and the ankle. Those usually needed a treatment combined with open reduction of fractures and resulted in a higher direct medical expenditure.</p
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