557 research outputs found

    How to Obtain Valid Generalized Modal Syllogisms from Valid Generalized Syllogisms

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    Making full use of the truth value definitions of sentences with quantification, possible world semantics and/or fuzzy logic, one can prove the validity of generalized modal syllogisms. This paper shows that the proof of the validity of a generalized modal syllogism can be transformed into that of its corresponding generalized syllogism, and that the generalized syllogism obtained by removing all modalities in any valid generalized modal syllogism is still valid. Therefore, the simplest way to screen out valid generalized modal syllogisms is to add modalities to valid generalized syllogisms, and then to delete all invalid syllogisms by means of the basic rules with which valid generalized modal syllogisms should meet. And then the remainders are valid. This paper illustrates how to obtain 12 valid generalized modal syllogisms by adding necessary modalities and/or possible modalities to any valid generalized syllogism. The two kinds of syllogisms discussed in this paper are composed of sentences with quantification which is the largest number of sentences in natural language. Hence, this innovative research can provide theoretical support for linguistics, logic, artificial intelligence, and among other fields

    Transmission eigenchannels and the densities of states of random media

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    We show in microwave measurements and computer simulations that the contribution of each eigenchannel of the transmission matrix to the density of states (DOS) is the derivative with angular frequency of a composite phase shift. The accuracy of the measurement of the DOS determined from transmission eigenchannels is confirmed by the agreement with the DOS found from the decomposition of the field into modes. The distribution of the DOS, which underlies the Thouless number, is substantially broadened in the Anderson localization transition. We find a crossover from constant to exponential scaling of fluctuations of the DOS normalized by its average value. These results illuminate the relationships between scattering, stored energy and dynamics in complex media.Comment: Supplementary Information included at the end of the documen

    Protective effect of ginsenoside Rd against isoproterenolinduced myocardial infarction in Wistar rats

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    Purpose: To investigate the protective effect of ginsenoside Rd (GRd) against isoproterenol (ISO)- induced myocardial infarction in a rat model.Methods: Forty healthy male rats were equally divided into four groups (10/group). Rats in the control group received only saline, whereas rats in GRd group were intraperitoneally (i.p.) injected GRd at a dose of 50 mg/kg body weight (b.wt.) for 14 days. The other two groups were ISO-treated rats. One group (MI model) received ISO at a dose of 80 mg/kg b.wt i.p. for 2 days, while the other group (GRd + ISO group) was pretreated with GRd at a dose of 50 mg/kg for 14 days prior i.p. administration of the same dose of ISO.Results: Treatment with GRd (for 14 days) prior to ISO exposure resulted in significant increase in the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) as well as significant decreases in heart-to-body weight ratio, infarct size, inflammatory markers {tumour nectosis factor alpha (TNF-α), nuclear factor kappa B (NF-κB), interleukin 1 beta (IL-1β) and interleukin 6 (IL-6)}, relative to ISO-treated rats (p > 0.05). In addition, prior exposure to ISO led to significant elevation in malondialdehyde (MDA), cardiac troponin T (cTnT), creatine kinase (CPK), lactate dehydrogenase (LDH) and apoptotic markers (caspase-3 and caspase-9). However, pre-treatment with GRd reversed the ISO-induced histopathological changes (necrosis/oedema and altered cardiac fibres) in cardiac tissue.Conclusion: These results demonstrate that GRd ameliorates ISO-induced cardiotoxicity in rats via upregulation of the activities of antioxidants, and suppression of inflammatory and apoptotic biomarkers. Thus, GRd has cardio-protective properties.Keywords: Ginsenoside Rd, Myocardial infarction, Apoptosis, Inflammation, Antioxidant

    Efficient Spectrum Sharing Between Coexisting OFDM Radar and Downlink Multiuser Communication Systems

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    This paper investigates the problem of joint subcarrier and power allocation in the coexistence of radar and multi-user communication systems. Specifically, in our research scenario, the base station (BS) provides information transmission services for multiple users while ensuring that its interference to a separate radar system will not affect the radar's normal function. To this end, we propose a subcarrier and power allocation scheme based on orthogonal frequency division multiple access (OFDM). The original problem consisting involving multivariate fractional programming and binary variables is highly non-convex. Due to its complexity, we relax the binary constraint by introducing a penalty term, provided that the optimal solution is not affected. Then, by integrating multiple power variables into one matrix, the original problem is reformulated as a multi-ratio fractional programming (FP) problem, and finally a quadratic transform is employed to make the non-convex problem a sequence of convex problems. The numerical results indicate the performance trade-off between the multi-user communication system and the radar system, and notably that the performance of the communication system is not improved with power increase in the presence of radar interference beyond a certain threshold. This provides a useful insight for the energy-efficient design of the system.Comment: 6 pages, 5 figure

    Toward Deep Learning-Based Human Target Analysis

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    In this chapter, we describe methods toward deep learning-based human target analysis. Firstly, human target analysis in 2D and 3D domains of radar signal is introduced. Furthermore, range-Doppler surface for human target analysis using ultra-wideband radar is described. The construction of range-Doppler surface involves range-Doppler imaging, adaptive threshold detection, and isosurface extraction. In comparison with micro-Doppler profiles and high-resolution range profiles, range-Doppler surface contains range, Doppler, and time information simultaneously. An ellipsoid-based human motion model is designed for validation. Range-Doppler surfaces simulated for different human activities are demonstrated and discussed. With the rapid emergence of deep learning, the development of radar target recognition has been accelerated. We describe several deep learning algorithms for human target analysis. Finally, a few future research considerations are listed to spark inspiration
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