Abstract SLM (selective laser melting) is an important additive manufacturing technology. Parts with complex structures can be produced by SLM, so surface cracks and other defects within parts are difficult to identified traditional nondestructive testing techniques. In this paper, ultrasonic technology proposed identify the crack of specimen. Because anisotropy residual stress specimen, time signal strongly interfered noise, which makes identification location difficult. To solve problem,...

When metro systems need to be temporarily closed due an unexpected disruption, the operators have arrange shuttle buses as alternative transport for trains, while passengers find new routes complete their journeys. However, additional bus lines might redundant if well-known phenomenon of "Braesss Paradox" exists. To address this issue, paper proposes a bi-level programming model in which objective upper-level is minimize number lines, lower-level UE (User Equilibrium) that simulates route...

In this paper, to solve disassembly sequence planning problem efficiently, Disassembly Feasibility Information Graph (DFIG) is presented firstly. Based on graph, the of converted into a searching optimal path in directed and weighted graph. Then, an ant colony optimization algorithm presented, integrated with part moving planner 3D system, build DFIG, search optimum solution(s). The tour represents possible product solution. pheromone trail laid edge by related quality its tour. It two steps...

The assembly hierarchy for a product design determines the subassembly module formation, tasks modules and serial-parallel material flow among these tasks. Automatic generation of candidate hierarchies by computer algorithms is critical step to exploring potential space system design, existing research on sequence identification has limitations in dealing with this challenge. This paper proposes use instead generate optimisation. Based liaison graphs, first characterises developing unique...

This paper investigates the interrelation and information flows between CNY-USD spot offshore, i.e., NDF, markets. We find that daily changes of NDF rates can be approximated by a MA (1)-GARCH (1, 1) model. Using GARCH formulation, this tests spillover effects in conditional mean volatility The results show there is effect from market to not other way round, exists both directions. means offshore transmitted domestic currency forward serves an important price discovery role. also financial...

Using the panel data of 13 cities in Beijing-Tianjin-Hebei region for 2003-2016 years, this paper constructs a spatial measurement model based on three different weights and studies evolution pattern industrial agglomeration region, impact total factor productivity (TFP) cities. The main conclusions are as follows: (1) manufacturing spreads from surrounding areas Beijing to southeast central southern regions Hebei province; Productive Service Industry has gradually spread northern part...

BIM technology plays an important role in design and construction. IFC standard is a principal for data exchange. In this paper, extended to substation gantry. The spatial physical structure expression of gantry based on studied, the system information model established. Substation modeling provides method exchange 3D will promote design.

In last two years, people have paid more and attentions to price fluctuations. China Centre Bank frequently uses the approach of adjusting interest rates influence This article will introduce a monetary policy model that covers different time periods, types disturbances. It also depicts durative directional track impulse in decade. And it evaluates how strong timely prices index reacts rate policy. Finally this does dynamic analysis on disturbance.

Abstract Flight-to-gate assignment problem is one of the focused issues in field air transportation management and optimization. This paper focuses on improving used airport gate utilization minimizing passenger transfer tension via making a reasonable flight-to-gate strategy. A two-stage mathematical model has been formulated. In first stage, we are aiming to minimize passengers. Based result from second stage aims increase rate gates. Finally, plan designed certify validity our model.

This paper focuses on the Intelligent Aircraft Trajectory Optimization (IATO) problem. A two-stage mixed integer programming model is proposed to minimize travel route of aircraft and number visited correction points. Two strategies called SP-MNCP MNCP-SP are presented reflect actual engineering requirements in intelligent controlling. The trade-off between shortest path minimum points investigated detail based numerical experiments real-world scenarios.

Following the rapid development of urban rail transit, networking operation will be an inevitable trend for transit. How to formulate reasonable train dispatching program and achieve total optimal efficiency has become key issue addressed. The cross-line subway can effectively reduce transfer station pressure improve service quality. This paper studies schedule optimization problem under mode a network, where time-dependent passengers demand is considered. A mixed integer linear (MILP) model...