Research on a New Single-End Fault Location Method for Single-Phase Grounding Faults of Transmission Lines Through Transition Resistance

A single-end fault location method for single-phase nonmetallic grounding faults of transmission lines in a double terminal system is studied and proposed. First, the reason for the poor accuracy of the single-end fault location method in case of single-phase nonmetallic grounding faults is analyzed theoretically, and the necessary conditions for the single-end accurate fault location are put forward. Second, under the necessary conditions of the single-end accurate fault location, according to the topology of fault component networks, the calculation method of the single-end accurate fault location of transmission lines in a double terminal system is studied. Moreover, the influence of line capacitance is considered in this fault location method, and a simple expression for calculating the fault distance is obtained. Finally, the transmission line with a single-phase nonmetallic grounding fault is modeled in PSCAD; therefore, the correctness and the ability against transition resistance of the new single-end fault location method are verified by simulation.

Mobile Terminal System of Intelligent College English Teaching and Training Mode

With the increasing maturity and wide application of wireless mobile communication technology and 4G networks, the use of mobile smart terminals has been popularized and has become an indispensable thing for people to live, study, and entertain. Taking college English course as an example, this paper aims to study the mobile terminal system of intelligent college English teaching and training mode. Based on the introduction of the concept, architecture, characteristics of WAP technology, and the development tools of WAP application software that need to be used in the teaching mode of the mobile terminal system, this article tentatively constructs a teaching mode of the mobile terminal system. The model is described, the collaborative filtering algorithm is proposed, and how to construct the matrix and calculate the similarity with the collaborative filtering algorithm is discussed. In order to verify the effectiveness of the system model, a test level comparison and a questionnaire survey of the teaching model were carried out. The experimental results of this article show that 91.8% of students said that their comprehensive English level has been improved in the process of applying the mobile terminal system teaching mode. In addition, 87.5% of the students said that it is necessary or basically necessary to use English for professional teaching and 76.2% of the students are very satisfied and basically satisfied with this model.

Investigation and MASH Full-Scale Crash Testing of the Buried-in-Backslope Terminal Compatible with Midwest Guardrail System

Buried-in-backslope (BIB) terminal designs for beam guardrails were developed under the National Cooperative Highway Research Program (NCHRP) Report 350 criteria for 27¾-in. high guardrail systems. The design terminates a W-beam guardrail installation by burying the end terminal in the backslope. When properly designed and located, this type of anchor eliminates the possibility of an end-on impact with the barrier terminal and minimizes the likelihood of vehicular intrusion behind the barrier. Considering the increase in guardrail height to 31 in. in recent years, there is a need to modify the BIB terminal design for a 27¾-in. high guardrail to satisfy current crashworthiness standard criteria for a 31-in. high guardrail. The crash tests reported in this paper were performed in accordance with the Manual for Assessing Safety Hardware (MASH) Tests 3-34 and 3-35 for non-gating terminals, which represent the tests considered necessary to demonstrate MASH compliance of the device. The TL-3 BIB terminal system met MASH requirements and is considered MASH compliant. It is considered suitable for implementation at V-ditch locations with a 4H:1V or flatter foreslope where a MASH TL-3 BIB terminal system is needed and/or desired.

The Two-Echelon Dual-Channel Models for the Intermodal Container Terminals of the China Railway Express Considering Container Accumulation Modes

China Railway Express (CR Express) is a pioneer of the Silk Road Economic Belt and the 21st Century Maritime Silk Road. The intermodal container terminal system consisting of a maritime terminal and a railway terminal is investigated in this paper. It connects the shipping route and the CR Express route. Typically, there are two container accumulation modes in the railway terminal to dispatch a train, i.e., the fixed-length and the fixed-time container accumulation modes. The intermodal container terminal system can be formulated as the two-echelon dual-channel supply chain model. The steady-state probability matrix is obtained by solving the equilibrium equations. The cooperation between the maritime terminal and the railway terminal is considered to accelerate the accumulation of the containers. The total revenue of the two terminals is used as the key system performance indicator. Numerical experiments are conducted to compare the fixed-length and the fixed-time container accommodation modes. The situations with and without cooperation between two terminals are also compared in the two container accumulation modes, respectively.