This paper discusses the parameter estimation of the multivariate normal distribution using Bayesian statistical methods. Traditionally, frequency statistical methods are used to estimate the parameters of the multivariate normal distribution, but this method may face sampling limitations and model complexity. In contrast, the Bayesian method can more effectively explain the uncertainty of parameter estimation by introducing prior information and subsequent reasoning, and show better robustness to data limitations or model complexity. Through literature review and empirical analysis, this paper demonstrates the benefits and potential of using Bayesian methods to estimate the parameters of the multivariate normal distribution, and proposes new ideas for parameter estimation of the multivariate normal distribution in various fields, such as providing new ideas and methods for portfolio management.

Nowadays, short videos have become a platform for many people to show their bodies and express their emotions, so that male couples can also take advantage of the short video platform to be more bold in publicizing their sexual orientation, and even to put their intimate relationships on display. And the gay community’s activism in public space facilitates their access to more media discourse and promotes the realization of their identity. However, such face value-based performances of intimacy may be nothing more than fantasies of romantic love woven by people.

PLA composite films with improved mechanical, barrier and antibacterial properties were prepared by solution casting using silane-functionalized nanofibrillated cellulose (MNFC) and chitosan-encapsulated zinc oxide nanoparticles (CS-ZnO) as dual fillers. Nanofibrillated cellulose was first soaked in an aqueous solution of zinc chloride and aluminum chloride to disrupt its hydrogen-bond network, then grafted with KH-570 (γ-methacryloyloxypropyl trimethoxysilane). This converted the cellulose from type I to type II polymorph and improved its compatibility with the hydrophobic matrix. The CS-ZnO nanohybrid was obtained by alkaline co-precipitation followed by chitosan coating, yielding a ZnO crystallite size of 18.4 nm from the Scherrer equation, with the coating limiting agglomeration. Films containing 1 to 15 wt% MNFC at a fixed CS-ZnO content of 0.25 wt% were characterized by FTIR, XRD, DSC, TGA, SEM/EDS, tensile testing, water vapor transmission measurement, and disk diffusion assay. At 5 wt% MNFC, the tensile strength reached 31.40 MPa, an increase of 113% over neat PLA, crystallinity rose from 8.67% to 35.2% and WVTR fell by 79.3% to 3.15 g/m²·24 h. Inhibition zones of 18.3 mm against E. coli and 15.7 mm against S. aureus were obtained, although the mechanisms responsible for that activity were not investigated here and are discussed only with reference to the literature. MNFC therefore acts as a nucleating and reinforcing filler, while CS-ZnO supplies antibacterial activity, and the combination offers a workable route to multifunctional biodegradable packaging films.