Search results

To solve the problem that the underwater vehicles is difficult to turn and exit in a small range in the face of complex marine environment such as concave and ring under the limitation of its limitation of its shape and maximum steering angle, this paper aims to propose an improved ant colony algorithm based on trap filling strategy and energy consumption constraint strategy.

Firstly, on the basis of searching the global path, the disturbed terrain was pre-filled in the complex marine environments. Based on the energy constraint strategy, the ant colony algorithm was improved to make the search path of the underwater vehicle meet the requirements of the lowest energy consumption and the shortest path in the complex obstacle environment.

The simulation results showed that the modified grid environment diagram effectively reduced the redundancy search and improved the optimization efficiency. Aiming at the problem of “the shortest distance is not the lowest energy consumption” in the traditional path optimization algorithm, the energy consumption level was reduced by 26.41% after increasing the energy consumption constraint, although the path length and the number of inflection points were slightly higher than the shortest path constraint, which was more conducive to the navigation of underwater vehicles.

The method proposed in this paper is not only suitable for trajectory planning of underwater robots but also suitable for trajectory planning of land robots.

China's economic transition is essentially the process of China's institutional changes. During the changes, the appearance of institutional innovation is not regular; instead, it is intermittent and random. The purpose of this paper is to show that the fitful appearance of institutional innovation is the root of China's economic growth and fluctuations.

This paper constructs a real business cycle (RBC) model introducing the institutional factor expressed in the quantitative form under the dynamic stochastic general equilibrium (DSGE) framework by measuring China's institutional changes quantitatively.

By comparing the characteristics of the actual economic data with those of the simulated economic data, we find that this RBC model can explain 94.44%, 66.07%, 23.46%, 21.03% and 15.45% of the cyclical fluctuations in output, investment, labor, consumption and capital, respectively.

The impulse response analysis finds that the institutional shocks have a relatively long duration, lasting about 30 years, and decline slowly over time, while technological shocks decline relatively fast, lasting approximately ten years.

This paper presents a generic simulation model to determine the equipment mix (quay, yard and intra-terminal transfer) for a Container Terminal Logistics Operations System (CTLOS). The simulation model for the CTLOS, a typical type of discrete event dynamic system (DEDS), consists of three sub-models: ship queue, loading-unloading operations and yard-gate operations. The simulation model is empirically applied to phase 1 of the Yangshan Deep Water Port in Shanghai. This study considers different scenarios in terms of container throughput levels, equipment utilization rates, and operational bottlenecks, and presents a sensitivity analysis to evaluate and choose reasonable equipment ratio ranges under different operational conditions.

Village-level archives are the most basic construction unit of rural archives in China, yet the village-level archival work is the most poorly delivered. However, the evolution of the laws and rules on village-level archival work in recent years signal that Chinese village-level archival work has stepped into a new era. In this context, this article aims to review the detailed history of village-level archival legislation, examine the legislation’ implementation effect and discuss the existing problems with a view to providing improvement measures.

A historical research method is used to review the legislation’ history, and the analysis involving the implementation effect is mainly based on literature of two kinds, which are investigation reports on sample villages’ archival work carried out by scholars, and summary reports and work schemes on national or local village-level archival work given by the archival management or administrative management departments at various level.

At first, China only issued non-legal administrative orders toward village-level archival work. Later, some regions issued local rules, and finally the national rules and even Archives Law with relevant provisions were promulgated. However, their implementation faced two fundamental problems; firstly the insufficient endogenous demand for archival work in some villages, and secondly the mechanism problem involving village level archives management. The countermeasures are also discussed building on these two points.

This is the first article to systematically combine a review of the history of Chinese village-level archival legislation and in addition to examine their implementation effect including analyzing the existing problems from the macro level.