Discrete event simulation tool for analysis of qualitative models of continuous processing systems

An artificial intelligence design and qualitative modeling tool is disclosed for creating computer models and simulating continuous activities, functions, and/or behavior using developed discrete event techniques. Conveniently, the tool is organized in four modules: library design module, model construction module, simulation module, and experimentation and analysis. The library design module supports the building of library knowledge including component classes and elements pertinent to a particular domain of continuous activities, functions, and behavior being modeled. The continuous behavior is defined discretely with respect to invocation statements, effect statements, and time delays. The functionality of the components is defined in terms of variable cluster instances, independent processes, and modes, further defined in terms of mode transition processes and mode dependent processes. Model construction utilizes the hierarchy of libraries and connects them with appropriate relations. The simulation executes a specialized initialization routine and executes events in a manner that includes selective inherency of characteristics through a time and event schema until the event queue in the simulator is emptied. The experimentation and analysis module supports analysis through the generation of appropriate log files and graphics developments and includes the ability of log file comparisons

Multi-rate, real time image compression for images dominated by point sources

An image compression system recently developed for compression of digital images dominated by point sources is presented. Encoding consists of minimum-mean removal, vector quantization, adaptive threshold truncation, and modified Huffman encoding. Simulations are presented showing that the peaks corresponding to point sources can be transmitted losslessly for low signal-to-noise ratios (SNR) and high point source densities while maintaining a reduced output bit rate. Encoding and decoding hardware has been built and tested which processes 552,960 12-bit pixels per second at compression rates of 10:1 and 4:1. Simulation results are presented for the 10:1 case only

Effect of Bound States on the Excitation Spectrum of a Heisenberg Ferromagnet at Low Temperature

A compact expression for the energy shift and inverse lifetime (energy width) of spin waves in a Heisenberg ferromagnet at low temperatures is given. The two-particle bound states are observable via the resonance they cause in the self-energy of spin waves

Dynamics of the Heisenberg Ferromagnet at Low Temperatures

Dyson calculated the effect of spin-wave interactions on the static (thermodynamic) properties of the Heisenberg ferromagnet. Within the same approximation, that of including only the contributions of lowest-order (two-magnon) scattering processes and neglecting the kinematic interaction, we have calculated the dynamic properties of this system and find results consistent with Dyson\u27s in the zero-wave-vector limit. In the short-wavelength limit where perturbation theory diverges, we discuss nonperturbatively via the t matrix the influence of the two-spin-wave bound states and the two-spin-wave resonant scattering states on the single-particle spectrum as characterized by the transverse spectral weight function Ak(ω). We find that although the total cross section of the bound states is too small for them to be observed directly, the anomalous effect of the bound states and resonant scattering states on the renormalization of the spin-wave energy is observable under favorable conditions. In general, we find the quasiparticle picture to be valid; however, at the highest temperature considered the resonant scattering states cause an extra resonance in the susceptibility. Most of the results for Ak(ω) are given numerically and have been checked against the sum rules, although the energy shift and energy width as deduced from Σk(εk) are given analytically by rather simple expressions. We have obtained for the first time a Green\u27s function that is capable of yielding correctly at low temperatures both the static and dynamic properties for arbitrary spin

China’s South–South Cooperation with Latin America and the Caribbean

Since the formation of the People’s Republic of China (PRC) in 1949, China’s political leaders have given priority to securing the country’s sovereignty, national unification, and territorial integrity. This has involved pursuing foreign relations that contribute to an international environment that is conducive to the country’s peaceful development as a prosperous socialist society. In pursuing these strategic goals, the Chinese government and state-owned corporations seek to establish economic and political relations with the Latin American and Caribbean (LAC) countries that are based on the principles and practices of South–South cooperation (SSC). This essay focuses on the extent to which China’s relations with these countries contribute to their mutual benefit, promote their common development, and support the formation of a new multipolar world order based on peace, mutuality, equity, environmental sustainability, and international cooperation

Arthopyrenia betulicola (Arthopyreniaceae, Dothidiomycetes), an Unusual New Lichenized Fungus From High Elevations of the Southern Appalachian Mountains

The crustose pyrenolichen Arthopyrenia betulicola is described as new to science based on collections from high elevations of Great Smoky Mountains National Park in eastern North America. The species is hypothesized to be endemic to the southern Appalachian Mountains where it occurs only on the bark of mature yellow birch (Betula alleghaniensis). It is a somewhat unusual member of the genus Arthopyrenia s.l. in consistently having a conspicuous photobiont layer of Trentepohlia. It differs from A. cinchonae, with which it is allopatric, by this feature as well as in having differently shaped and narrower ascospores

Differences in unpleasantness induced by experimental pressure pain between patients with fibromyalgia and healthy controls

Pain possesses both sensory and affective dimensions, which are highly correlated yet distinct. Comparison of these dimensions within experimental pain settings has resulted in the construct of relative unpleasantness. Relative unpleasantness is defined as the amount of affective unpleasantness elicited for a given sensory magnitude. The aim of this study was to determine the relationship between affective and sensory components of evoked pain in subjects with fibromyalgia (FM) and healthy controls. Here we show that patients with FM unexpectedly display less relative unpleasantness than healthy controls in response to random noxious pressure stimuli. Relative unpleasantness was not correlated with distress, anxiety, or depression, which were pronounced in the FM group. Clinical pain in patients with FM was perceived to be more unpleasant than the evoked pain stimuli. These results are consistent with the concept that chronic pain may reduce the relative unpleasantness of evoked pain sensations

Engineering design of artificial vascular junctions for 3D printing

Vascular vessels, including arteries, veins and capillaries, are being printed using additive manufacturing technologies, also known as 3D printing. This paper demonstrates that it is important to follow the vascular design by nature as close as possible when 3D printing artificial vascular branches. In previous work, the authors developed an algorithm of computational geometry for constructing smooth junctions for 3D printing. In this work, computational fluid dynamics (CFDs) is used to compare the wall shear stress and blood velocity field for the junctions of different designs. The CFD model can reproduce the expected wall shear stress at locations remote from the junction. For large vessels such as veins, it is shown that ensuring the smoothness of the junction and using smaller joining angles as observed in nature is very important to avoid high wall shear stress and recirculation. The issue is however less significant for capillaries. Large joining angles make no difference to the hemodynamic behavior, which is also consistent with the fact that most capillary junctions have large joining angles. The combination of the CFD analysis and the junction construction method form a complete design method for artificial vascular vessels that can be 3D printed using additive manufacturing technologies