A Multiscale Tiered Approach to Quantify Contributions: A Case Study of PM2.5 in South Korea During 2010–2017

We estimated long-term foreign contributions to the particulate matter of 2.5 μm or less in diameter (PM2.5) concentrations in South Korea with a set of air quality simulations. The Weather Research and Forecasting (WRF)-Sparse Matrix Operator Kernel Emissions (SMOKE)-Community Multiscale Air Quality (CMAQ) modeling system was used to simulate the base and sensitivity case after a 50% reduction of foreign emissions. The effects of horizontal modeling grid resolutions (27- and 9-km) was also investigated. For this study, we chose PM2.5 in South Korea during 2010–2017 for the case study and emissions from China as a representative foreign source. The 9-km simulation results show that the 8-year average contribution of the Chinese emissions in 17 provinces ranged from 40–65%, which is ~4% lower than that from the 27-km simulation for the high-tier government segments (particularly prominent in coastal areas). However, for the same comparison for low-tier government segments (i.e., 250 prefectures), the 9-km simulation presented lowered the foreign contribution by up to 10% compared to that from the 27-km simulation. Based on our study results, we recommend using high-resolution modeling results for regional contribution analyses to develop an air quality action plan as the receptor coverage decreases.

On Solvability in the Class of Distributions of Degenerate Integro-Differential Equations in Banach Spaces

The paper considers a new approach to constructing generalized solutions of degenerate integro-differential equations convolution type in Banach spaces. The principal idea of the method proposed implies the refusal of the condition of existence of the full Jordan set for the Fredholm operator of the higher derivative with respect to the operator bundle formed by the rest of operator coefficients of the differential part and by the operator kernel of the integral component of the equation. The conditions are superimposed upon the values of the operator function specially constructed on the basis elements of the Fredholm operator kernel. Under such an approach, the differential part of the equation may include not only the higher derivative but also any combination lower derivatives, what allows one to consider the convolution integral-differential equations from universal positions, without any special account of the structure of the structure of the operator bundle. The method proposed represents a form of generalization of the technique based on the application of Jordan sets of Fredholm operators, and in the case of existence of the latter the method coincides with this technique. The generalized solutions are constructed in the form of a convolution of the fundamental operator function, which corresponds to the equation under investigation, and a function, which includes the right-hand side of the equation and the initial data. The conditions, under which such a generalized solution does not contain any singular component, and the regular component converts the initial equation into an identity and satisfies the initial data, and the result will provide for the resolvability of the initial problem in the class of functions of characterized by the respective smoothness. In this case, the generalized solution constructed will be classical. The theorem on the form of fundamental operator function has been proved, the abstract results have been illustrated via examples of initialboundary value problems of applied character from the theory electromagnetic fields, the theory of oscillations in visco-elastic media, the theory of vibrations of thermal-elastic plates.

Simulation of Quasistationary Electromagnetic Fields in Regions Containing Disconnected Conducting Subregions

Methods for a numerical solution of Maxwell's equations in the quasistationary aproximation in a region with multiply connected conducting subregions were discussed. The case of nontrivial operator kernel was explored. The methods for finding the solution of the linear algebraic equations system were analyzed. The method of introducing a "fictional armature" was offered as alternative method for searching [retrieving] a normal solution of linear algebraic equations. Results of computational experiments were presented. The study was carried out on the example of calculation for electrodynamic acceleration process in the railgun channel

Inventário de Emissões com Alta Resolução para a Região da Grande Vitória Utilizando o Sistema de Modelagem Integrada WRF-SMOKE-CMAQ

Resumo A poluição atmosférica proveniente das atividades antropogênicas tem provocado incômodo à população da Região Metropolitana da Grande Vitória (RGV), Espirito Santo, Brasil. Muitos pacientes como asmáticos, alérgicos, químico sensíveis, cardiacos, pessoas com acidente vascular cerebral (AVC), diabetes, grávidas, idosos e crianças são especialmente suscetíveis a uma pobre qualidade do ar. As complexas interações dos poluentes atmosféricos podem ser entendidas usando modelos de transporte químico, os quais necessitam de inventários de emissões para prover a alocação espacial e temporal das emissões. Na RGV, o Instituto Estadual do Meio Ambiente (IEMA) disponibilizou o inventário de emissões da região para o ano de 2010. Nesse artigo foi realizada uma adaptação do inventário de fontes regional para o Sparse Matrix Operator Kernel Emissions (SMOKE) de modo a ser utilizado em modelos de qualidade do ar (MQA) como o Community Multi-scale Air Quality (CMAQ) Modeling System e outros modelos fotoquímicos. Foram obtidos valores simulados elevados referentes às emissões de ressuspensão em vias, apontando uma possível falha do inventário neste tipo de fonte. Utilizando os fatores de emissão médios de Abu-Allaban et al. (2003) para a ressuspensão das vias locais, foram obtidos resultados mais condizentes aos atuais níveis de concentrações de partículas monitorados na RGV.

Reconstruction of a convolution operator from the right-hand side on the semiaxis

In this paper, a Volterra integral equation of the first kind in convolutions on the semiaxis when the integral operator kernel and the right-hand side of the equation have a bounded support is considered. An inverse problem of reconstructing the solution to the equation and the integral operator kernel from values of the right-hand side is formulated. Necessary and sufficient conditions for the inverse problem solvability are obtained. A uniqueness and stability theorem is proved. Explicit formulas for reconstruction of the solution and kernel are obtained.

An Empirical Study for the Estimation of Autoregressive Hilbertian Processes by Wavelet Packet Method

In this paper wavelet packet bases are used for an estimation of the autoregressive Hilbertian processes operator. We assume that integral operator kernel can have some singular structures and estimate them by projecting functional processes on suitable bases. Linear methods for continuous-time prediction using Hilbert-valued autoregressive processes are compared with the suggested method on simulated data and on real-life data sets. Statistics of residual partial sums processes and Ex poste prediction are used to check the model.

Audible-frequency stiffness of a primary suspension isolator on a high-speed tilting bogie

The preload-dependent dynamic stiffness of a primary suspension isolator on a high-speed tilting bogie is examined via measurements and modelling within an audible frequency range. The stiffness is found to depend strongly on both frequency and preload. The former displays some resonance phenomena, such as stiffness peaks and troughs, while the latter exhibits a steep low-frequency stiffness increase in addition to an anti-resonance peak shifting to a higher frequency with increased preload. The problems of simultaneously modelling the preload and frequency dependence are removed by adopting a frequency-dependent waveguide approach, assuming incompressible rubber with an Abel operator kernel as its shear relaxation function. The preload dependence is modelled by a non-linear shape factor based approach, using a globally equivalent preload configuration. All the translational stiffnesses are modelled, including the vertical, longitudinal and lateral directions, and the vertical stiffness results are compared to those of measurements in a specially designed test rig. Good agreement is obtained for a wide frequency domain-covering 100-600 Hz-using a minimum number of parameters and for a wide preload domain-from vanishing to the maximum in service, 90 kN.