Symmetric Rigidity for Circle Endomorphisms with Bounded Geometry

Let $f$ and $g$ be two circle endomorphisms of degree $d\geq 2$ such that each has bounded geometry, preserves the Lebesgue measure, and fixes $1$. Let $h$ fixing $1$ be the topological conjugacy from $f$ to $g$. That is, $h\circ f=g\circ h$. We prove that $h$ is a symmetric circle homeomorphism if and only if $h=Id$. Many other rigidity results in circle dynamics follow from this very general symmetric rigidity result.Comment: 22 pages, 5 figure

Effect of Chlordimeform on Cardiovascular Function in Occupational Exposures

A b s t r a c t : E f f e c t o f C h l o r d i m e f o r m o n Cardiovascular Function in Occupational Exposures: Zhijun ZHOU, et al. Department of O c c u p a t i o n a l H e a l t h , S h a n g h a i M e d i c a l University-To understand the possible effects of an insecticide, chlordimeform, on the human cardiovascular system, this work was carried out. Pre-and postexposure, the medical examinations, especially cardiovascular functions, were meticulously done in farmers spraying 0.125% solution of chlordimeforme for 3 consecutive days and packers packing chlordimeform for one month. The exposure level was measured by means of the urinary excretion of chlordimeform and its main metabolite, 4-chlor-o-tolumidine, as well as the air concentration in the work place and skin contamination by using a regional proportional sampling strategy. The alterations, though mild and diverse, were significant compared to their own pre-exposure background. The changes in heart rate, blood pressure and some EKG parameters, such as T wave, P wave, PR interval and Qt interval were noticed. The cardiovascular functional changes were usual and sensitive findings in the exposed persons, and their importance in health surveillance needs to be emphasized. (J Occup Health 1999; 41: 59-61

Analysis of factors affecting the effectiveness of oil spill clean-up: A bayesian entwork approach

Ship-related marine oil spills pose a significant threat to the environment, and while it may not be possible to prevent such incidents entirely, effective clean-up efforts can minimize their impact on the environment. The success of these clean-up efforts is influenced by various factors, including accident-related factors such as the type of accident, location, and environmental weather conditions, as well as emergency response-related factors such as available resources and response actions. To improve targeted and effective responses to oil spills resulting from ship accidents and enhance oil spill emergency response methods, it is essential to understand the factors that affect their effectiveness. In this study, a data-driven Bayesian network (TAN) analysis approach was used with data from the U.S. Coast Guard (USCG) to identify the key accident-related factors that impact oil spill clean-up performance. The analysis found that the amount of discharge, severity, and the location of the accident are the most critical factors affecting the clean-up ratio. These findings are significant for emergency management and planning oil spill clean-up efforts.Postprint (published version

Solution Growth and Thermal Treatment of Crystals Lead to Two New Forms of 2-((2,6-Dimethylphenyl)Amino)Benzoic Acid

We report the discovery of two new forms (II and III) of a potential non-steroidal anti-inflammatory and thyroid drug, 2-((2,6-dimethylphenyl)amino)benzoic acid (HDMPA) through solution growth and thermal treatment of crystals. Form II has been discovered through crystal growth in a variety of solvents, and characterized by single-crystal X-ray diffraction, powder X-ray diffraction (PXRD), FT-IR, and Raman spectroscopy. Form II converts into form III upon thermal treatment, as indicated by the phase behavior study of form II with differential scanning calorimetry (DSC). Form III has been characterized by IR, Raman and PXRD. Conformational flexibility of the molecule seems to lead to the polymorphism of the system. A conformational scan shows the conformational minima correspond to the conformers in the polymorphs. Lattice energy calculations show energies of −48.14 and −50.31 kcal mol−1 for forms I and II, providing information on the relative stability for each form. Hirshfeld analysis revealed that intermolecular interactions such as C⋯C, H⋯H, C⋯H, and H⋯O contribute to the stability of the crystal forms

Stability Analysis of Bipedal Robots Using the Concept of Lyapunov Exponents

The dynamics and stability of passive bipedal robot have an important impact on the mass distribution, leg length, and the angle of inclination. Lyapunov’s second method is difficult to be used in highly nonlinear multibody systems, due to the lack of constructive methods for deriving Lyapunov fuction. The dynamics equation is established by Kane method, the relationship between the mass, length of leg, angle of inclination, and stability of passive bipedal robot by the largest Lyapunov exponent. And the Lyapunov exponents of continuous dynamical systems are estimated by numerical methods, which are simple and easy to be applied to the system stability simulation analysis, provide the design basis for passive bipedal robot prototype, and improve design efficiency

An Underwater Image Enhancement Algorithm Based on MSR Parameter Optimization

The quality of underwater images is often affected by the absorption of light and the scattering and diffusion of floating objects. Therefore, underwater image enhancement algorithms have been widely studied. In this area, algorithms based on Multi-Scale Retinex (MSR) represent an important research direction. Although the visual quality of underwater images can be improved to some extent, the enhancement effect is not good due to the fact that the parameters of these algorithms cannot adapt to different underwater environments. To solve this problem, based on classical MSR, we propose an underwater image enhancement optimization (MSR-PO) algorithm which uses the non-reference image quality assessment (NR-IQA) index as the optimization index. First of all, in a large number of experiments, we choose the Natural Image Quality Evaluator (NIQE) as the NR-IQA index and determine the appropriate parameters in MSR as the optimization object. Then, we use the Gravitational Search Algorithm (GSA) to optimize the underwater image enhancement algorithm based on MSR and the NIQE index. The experimental results show that this algorithm has an excellent adaptive ability to environmental changes