7 research outputs found

    A Low Complexity Fixed Sphere Decoder with Statistical Threshold for MIMO Systems

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    A Noise-Shaped Signaling Method for Vehicle-to-Everything Security

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    This paper presents a method to improve the Vehicle-to-Everything (V2X) security. With the recent rapid development of communication technology and traffic applications, V2X is recently commercialized and has been growing as a fundamental system for future applications. Because of the high mobility of the vehicles, V2X requires a low latency and high-reliability. However, previous security methods demand a large computational burden and generate high latency owing to complex operations and long additional data bits for ensuing security. To resolve such constraints, an advanced security method ensuring lower latency and higher reliability is required. We propose a noise-shaped signaling method that provides high-level security with low latency for reliable V2X communication. The proposed method encrypts original data symbols to noise-like symbols by applying a noise envelope that consists of Chaotic Random Magnitude Sequence (CRMS) and Chaotic Random Phase Sequences (CRPS). Our method simplifies the sequence sharing process between a sender and an intended receiver by adapting the characteristics of a chaotic dynamic system. Moreover, the proposed method does not demand additional data bits and generate delay because the method only uses simple multiplication and division procedure for data encryption in the physical layer. We analyze our method in depth using extensive simulations and various viewpoints such as error rate, probability of modulation identification. From the simulations, we demonstrate that a malicious adversary cannot comprehend the transmitted symbols and always has the maximum error rate under various network environments and conditions. We also demonstrate how the adversary cannot infer the modulation scheme from the symbols applying the proposed method. After these analyses, we confirm that the noise-shaped signaling method is high-level of secure method with a low latency for V2X communication

    Measurements of the Specific Activities of 137Cs in Antarctica Environmental Samples by Using the Low-Level Radiation Analysis Method

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    © 2020, The Korean Physical Society. Since the King Sejong Korean Antarctic Research Station began operation in 1988, studies of various fields have been then carried out in polar regions and significant achievements have been yielded. However, environmental and biological radiations have not been dealt with compared to other research areas. In this study, the 137Cs distribution is investigated for environmental elements in the vicinity of the two research stations, the Jang Bogo Station and the King Sejong Station, operated by the Korea Polar Research Institute (KOPRI) in Antarctica by using a low-level radiation analysis method. Three different types of environmental samples, soils, mosses, and lichens are investigated for identification of 137Cs. In order to discriminate low levels of radiations from background radiations and estimate their specific activities with high reliability and precision, we used a heavily shielded HPGe detector in an underground laboratory to perform the activity measurements. GEANT4 simulations were carried out for efficiency calibrations corresponding to the shape of the pre-processed sample. 137Cs has been identified in all the samples and the energy spectrum has been found to reflect their physical and ecological characteristics11sciekc

    Modeling, Verification, and Signal Integrity Analysis of High-Speed Signaling Channel with Tabbed Routing in High Performance Computing Server Board

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    It is necessary to reduce the crosstalk noise in high-speed signaling channels. In the channel routing area, the tabbed routing pattern is used to mitigate far-end crosstalk (FEXT), and the electrical length is controlled with a time domain reflectometer (TDR) and time domain transmission (TDT). However, unlike traditional channels having uniform width and space, the width and space of tabbed routing changes by segment, and the capacitance and inductance values of tabbed routing also change. In this paper, we propose a tabbed routing equivalent circuit modeling method using the segmentation approach. The proposed model was verified using 3D EM simulation and measurement results in the frequency domain. Based on the calculated inductance and capacitance parameters, we analyzed the insertion loss, FEXT, and self-impedance in the frequency domain, and TDT and FEXT in the time domain, by comparing the values of these metrics with and without tabbed routing. Using the proposed tabbed routing model, we analyzed tabbed routing with variations of design parameters based on self- and mutual-capacitance and inductance

    36-month clinical outcomes of patients with venous thromboembolism: GARFIELD-VTE

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    Background: Venous thromboembolism (VTE), encompassing both deep vein thrombosis (DVT) and pulmonary embolism (PE), is a leading cause of morbidity and mortality worldwide.Methods: GARFIELD-VTE is a prospective, non-interventional observational study of real-world treatment practices. We aimed to capture the 36-month clinical outcomes of 10,679 patients with objectively confirmed VTE enrolled between May 2014 and January 2017 from 415 sites in 28 countries.Findings: A total of 6582 (61.6 %) patients had DVT alone, 4097 (38.4 %) had PE +/- DVT. At baseline, 98.1 % of patients received anticoagulation (AC) with or without other modalities of therapy. The proportion of patients on AC therapy decreased over time: 87.6 % at 3 months, 73.0 % at 6 months, 54.2 % at 12 months and 42.0 % at 36 months. At 12-months follow-up, the incidences (95 % confidence interval [CI]) of all-cause mortality, recurrent VTE and major bleeding were 6.5 (7.0-8.1), 5.4 (4.9-5.9) and 2.7 (2.4-3.0) per 100 person-years, respectively. At 36-months, these decreased to 4.4 (4.2-4.7), 3.5 (3.2-2.7) and 1.4 (1.3-1.6) per 100 person-years, respectively. Over 36-months, the rate of all-cause mortality and major bleeds were highest in patients treated with parenteral therapy (PAR) versus oral anti-coagulants (OAC) and no OAC, and the rate of recurrent VTE was highest in patients on no OAC versus those on PAR and OAC. The most frequent cause of death after 36-month follow-up was cancer (n = 565, 48.6 %), followed by cardiac (n = 94, 8.1 %), and VTE (n = 38, 3.2 %). Most recurrent VTE events were DVT alone (n = 564, 63.3 %), with the remainder PE, (n = 236, 27.3 %), or PE in combination with DVT (n = 63, 7.3 %).Interpretation: GARFIELD-VTE provides a global perspective of anticoagulation patterns and highlights the accumulation of events within the first 12 months after diagnosis. These findings may help identify treatment gaps for subsequent interventions to improve patient outcomes in this patient population
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