Systems Engineering - Theory & Practice最新文献

In the current Chinese surname system, children adopt their father's surname. According to the deep-rooted traditional conception formed in the past thousands of years, people are willing to have a son to continue their family line. This has caused increasingly serious imbalance in the proportion between male and female populations and can bring about relevant social problems. The aim of this study is to design a new surname system for the Chinese nation, i.e. children will adopt neither their father's surname nor their mother's surname, and their parents' surnames can be inferred according to their surnames, so as to attain the goals that men and women are equal and it is the same to give birth to a son or a daughter. The method is to provide a relevant algebraic system and make the surname and the first character of the name correspond to the relevant codes in the said algebraic system; and then infer someone's genealogical structure through relevant operation. The design method of the surname system with 3ⁿ surnames is given, and illustrate it by taking as an example the design method of 9 surnames. Currently, in almost all the countries in the world, children adopt their father's surname, and the aforesaid design method, in principle, is applicable to other countries or nations.

This article presents the study of price formation mechanisms and the stability in distribution channels with differentiated products. First, the price settings are given under four different control patterns. The analysis result of price formation mechanism shows that the control pattern of distribution channel influences the price setting and the payoff of every player. Finally, we analyses the stability of the price setting and identify out the stability status. For unstable price formation, the critical discount factor is computed out.

A speed synchronization control strategy for multiple induction motors, based on adjacent cross-coupling control structure, is developed by employing total sliding mode control method. The proposed control strategy is to stabilize speed tracking of each induction motor while synchronizing its speed with the speed of the other motors so as to make speed synchronization error amongst induction motors converge to zero. The global stability and the convergence of the designed controller are proved by using Lyapunov method. Simulation results demonstrate the effectiveness of the proposed method.

This article first studied the nature of multiregional CGE models and reviewed relevant studies in such models. The article also constructed a static eight-region CGE model using an interregional input-output table for China. The model reflected the sizes of economies and differences in industrial structures across regions. More importantly, based on related empirical research, the model characterized the main economic relations across regions, such as interregional commodity flows, labor flows, and capital flows. Finally, some simulations were carried out to reveal the important effect that comes from the regional differences and linkages. The results shows the specifications of the regional differences and key linkages have significant influences on policy analysis.

In this article, we develop an optimal hedging ratio model with skewness and derive the analytical solution of the optimal hedging ratio which can degenerate to mean-variance hedging ratio when co-skewnesses of spot and futures returns become zero. The empirical results suggest that the hedging model with skewness performs better than the traditional mean-variance hedging model.

The relationship between multidisciplinary design optimization (MDO) for aircrafts and the large-scale system theory was expatiated. Using the large-scale system theory, the system was decomposed gradually based on the different classification standards and the system characteristics. At the same time, the MDO methods for aircrafts were classified according to the decomposition-coordination method of the large-scale system theory. The theory background and applicable range of each algorithm were elucidated. Aircraft design system is a typical engineering large-scale system, and the basic of MDO for aircrafts is the large-scale system theory. Therefore, the large-scale system theory and MDO for aircrafts should be studied simultaneously to improve the MDO.

According to the structured element method, the article investigates a method of solving the general fuzzy linear systems and dual general fuzzy linear systems, which are linear formed by fuzzy structured element, and gives the necessary and sufficient condition for the existence of a fuzzy solution. At the same time, some examples in engineering and economics are designed.

This article explores the function of trade credit in coordinating supply chain under both symmetric and bilateral asymmetric information. The financing function and positive externality of trade credit are also illustrated in this article. In a supply chain composed of a manufacturer and a budget constraint retailer, the manufacturer can use trade credit to finance the retailer and thus increases the retailer's order size up to the supply chain's optimal lot size. The benefit of coordination is allocated randomly among the parties by setting the length of the trade credit. When the retailer sells multiple products, trade credit's positive externality, that is one supplier's trade credit can increase the other supplier's profit, is demonstrated. When both the retailer and the manufacturer have private information, we use double auction model to derive the length of the credit. Numerical example is conducted to demonstrate the theoretical results.

The prediction of drought crop area is the basis of agricultural development in our country. According to grey system theory and Markov chain principle, applying a single gene system cloud grey SCGM(1,1)_c model to fit the development tendency of the few time series, its error index is stochastically fluctuated. Markov chain method is suitable for forecasting stochastic fluctuating dynamic process, selecting weighted Markov chain to predict the error index. Combining the advantages of the two models, we found a weighted SCGM(1,1)_c model for drought crop area prediction, and the new model is suitable for forecasting such kinds of system with in a short time, with few data, and stochastic fluctuating dynamic process. The example shows that the weighted SCGM(1,1)_c model can have high prediction precision for drought crop area.

This article studies the parameter design and the performance optimization of a Kanban system without stockouts in a multi-stage, mixed-model assembly line. The model of a Kanban system based on production processes is established by examining the relationship among the set-up time, the amount of work in process (WIP), the capacity indicated by a Kanban, and the takt-time ratio. A novel method for optimizing performance on the premise of no stockouts is proposed. Empirical results show that the amount of WIP is reduced remarkably after optimization.