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According to the existing personnel structure, quantity, development strategy, and market demand of the Shuohuang Railway Company’s operation and maintenance project, the demand quantity of various employees of the company for the past three years is predicted, and a human resource optimization model based on existing human resources and future plans is established. Then, the optimal solutions of the two mathematical models were calculated and analyzed using LINGO software. Finally, combined with the actual situation, the optimal allocation of human resources for the operation and maintenance project of KY company was obtained. The following conclusions are obtained. (1) For the optimal allocation model of existing human resources, the maximum net profit of the optimal staffing model is CNY 3258000. (2) The human resources allocation cost of the minimum dismissal model is CNY 81000. (3) The human resources allocation cost of the lowest cost model is CNY 15500. The research results can effectively guide the human resource management of the operation and maintenance project of the Shuohuang Railway Company, and have important theoretical and practical significance for further analysis of human resources model and its optimal allocation method.

Analytical models for vias and traces are presented for simulation of multilayer interconnects at the package and printed circuit board levels. Vias are modeled using an analytical formulation for the parallel-plate impedance and capacitive elements, whereas the trace-via transitions are described by modal decomposition. It is shown that the models can be applied to efficiently simulate a wide range of structures. Different scenarios are analyzed including thru-hole and buried vim, power vias, and coupled traces routed into different layers. By virtue of the modal decomposition, the proposed method is general enough to handle structures with mixed reference planes. For the first time, these models have been validated against full-wave methods and measurements up to 40 GHz. An improvement on the computation speed of at least two orders of magnitude has been observed with respect to full-wave simulations. [ABSTRACT FROM AUTHOR]

What package improvements are required for dense, high-aggregate bandwidth buses running at data rates beyond 10 Gb/s per channel, and when might optical interconnects on the board be required? We present a study of distance and speed limits for electrical on-board module-to-module links with an eye to answering these questions. Hardware-validated models of advanced organic modules and printed circuit boards were used to explore these limits. Simulations of link performance performed with an internal link modeling tool allowed us to explore the effect of equalization and modulation formats at different data rates on link bit error rate and eye opening. Our link models have been validated with active, high-speed differential bus measurements utilizing a 16-channel link chip with programmable equalization and a per-channel data rate of up to 11 Gb/s. Electrical signaling limits were then determined by extrapolating these hardware-correlated models to higher speeds, and these limits were compared to the results of recent work on on-board optical interconnects. [ABSTRACT FROM AUTHOR]

This paper reports major improvements to a 3-D full wave solver for a microstrip line and through-hole via in layered media. The interior layer problem, consisting of vias between two reference planes, is solved using the Foldy-Lax multiple scattering equations. The exterior layer problem is solved using the method of moments (MoM) with the layered media Green's functions. The exterior layer and interior layer problems are combined to obtain the S-parameters of the trace and through-hole via. A fast approach for calculating the layered-medium Green's functions using the numerical modified steepest descent path method is utilized. The Green's functions require milliseconds to compute per point. Schemes for efficiently computing image contributions for the static portion of the mixed potential Green's function are also implemented to solve the neighboring or self-RWG (basis function) interaction in the MoM problem. To validate the accuracy of the solution, extensive comparison with Ansoft's HFSS versions 9 and 11 for different pad sizes and antipad sizes are presented. The CPU per frequency is also tabulated to demonstrate the speed of the approach in this paper. [ABSTRACT FROM AUTHOR]

The effects of a random rough surface between dielectric and lossy conductive medium on power absorption are analyzed by considering incident plane waves impinging on the interface. We use two methods to formulate and solve the 2-D problem: the two-media small perturbation method to second order (SPM2) and the numerical system transfer operator matrix method, referred to as T-matrix method. The two methods are in agreement within the regimes of validity. The results show significant difference between absorption of a rough surface and that of a smooth surface. Surface fields are further examined numerically. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 7–13, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22023 [ABSTRACT FROM AUTHOR]

The effects of a random rough surface on the absorption by a metallic surface at microwave frequencies are analyzed by using two methods: the analytic small perturbation method and the numerical method of moments method. The results show significant difference between absorption of a rough surface and that of a smooth surface. The absorption depends on the root mean square height, correlation length, and correlation function of the random rough surface. The similarities with and differences from Morgan's classical result and the Hammerstad and Bekkadal formula are discussed. It is shown that for multiscale rough surfaces, saturation of absorption does not occur, or occurs at much higher frequencies. [ABSTRACT FROM PUBLISHER]