Academy of Military Transportation
Academy of Military Transportation
Wang L.,Academy of Military Transportation |
Wang L.,Tianjin University |
Li H.,Hebei University of Technology |
Zhao X.,Academy of Military Transportation |
Zhang Q.,Tianjin University
Tunnelling and Underground Space Technology | Year: 2017
When rock tunnel boring machines (TBMs) advance into rock with high strength and hardness, serious cutter wear can result, which greatly obstructs construction efficiency and safety. In this work, disc cutter wear evolution under the action of hard rock is investigated by theoretical analysis and experimental methods. Based on a mechanics analysis of the contact area between the disc cutter and rock, the relationship is determined between the slip ratio of disc cutter and the penetration and cutting coefficient of TBM. And on this basis, the wear mechanism of the cutter ring surface material is specifically analyzed to propose a new theory model for cutter wear evolution. To develop and apply this model further, a series of wear simulation tests are performed to validate this model and establish an application model for a specific project. The application model's effectiveness is preliminarily verified by project data obtained on site. This study provides a new feasible method for real-time prediction of disc cutter wear conditions and a basis for optimizing the boring parameters and prolonging the life of disc cutters used with rock TBMs. © 2017 Elsevier Ltd
Wang L.,Tianjin University |
Wang L.,Academy of Military Transportation |
Kang Y.,Tianjin University |
Cai Z.,Tianjin University |
And 4 more authors.
Tunnelling and Underground Space Technology | Year: 2012
Prediction of disc cutter wear extent is a critical factor for improving the working performance of tunnel boring machines (TBMs). In this study, three TBM working performance parameters are demonstrated to be directly influenced by disc cutter wear and selected as factors that predict disc cutter wear extent; new equations that describe the specific energy (SE) requirement of all disc cutters on the cutterhead are developed, and the SE rule is revealed based on mechanical analysis of the disc cutters as they cut hard rock. Two particular project cases are analysed to verify the above research results. The SE rule varies with disc cutter radius, while the change in disc cutter radius directly reflects the cutter wear extent. Consequently, the cutter wear extent can be predicted utilising the SE rule. Furthermore, the wear mechanism is investigated for the prediction of disc cutter wear extent. Lastly, a novel energy method is established that is based on the SE rule and the wear mechanism. In application, the average wear extent of all disc cutters on the cutterhead can be calculated using the SE equations, and the wear extent of each cutter can be predicted according to wear mechanism and the layout of the disc cutters on the cutterhead. To illustrate the applicability of this energy method, data from on-site Qinling tunnel boring are analysed in detail as an example. The establishment of this method is based on mechanical analysis of the disc cutter as it cuts hard rock; the parameters used in this method reflect rock mass properties and vary from moment to moment as disc cutter wear changes. Therefore, this method is well founded and can be used for real-time prediction of disc cutter wear for hard rock TBMs. © 2011 Elsevier Ltd.
Sun X.,Tsinghua University |
Lu H.,Tsinghua University |
Wu J.,Tsinghua University |
Wu J.,Academy of Military Transportation
Neurocomputing | Year: 2013
Transit signal priority (TSP), which is one of the most important issues in intelligent transportation systems, aims to provide priority signals with an advanced inspection system to public transport vehicles. In this paper, by introducing the advanced object detection technique into intelligent transport systems, we propose an automatic bus detection algorithm and apply it to the transit signal priority (TSP) system. The contributions of this paper fall into two folds: (1) we propose a bus detection algorithm. In this algorithm, an illumination-independent color feature is used for bus detection, which is useful in practical illumination environments. In addition, the widely-used sparse representation technique is extended to cost-sensitive kernel sparse representation, that can effectively combine different features for bus detection. (2) A transit signal priority control scheme is proposed based on the bus detection results. This control scheme optimizes the traffic lights signal according to whether a bus is coming or not. Experimental and simulation results show that the proposed intelligent TSP system based on bus detection is effective. © 2013 Elsevier B.V.
Pang G.,Academy of Military Transportation
Proceedings of the 2011 Chinese Control and Decision Conference, CCDC 2011 | Year: 2011
In this paper, the optimal strategy of transnational supply chain is analyzed when the demand distribution and market exchange rate are fluctuated by emergencies. The optimal order quantity of assembly transnational corporations and the trade price of parts supplier are changed under the market demand changed larger or less. The conclusions show that the supplier will adjust his production plan properly when the demand scale and market exchange rate are changed larger. This paper also reveals that the wholesale price will increase as market demand increases and the wholesale price will decrease as market demand decreases. An interesting economic insight is that the production plan is not usually adjusted. © 2011 IEEE.
An Y.-Q.,Academy of Military Transportation |
Wang Y.-J.,Academy of Military Transportation |
Gao W.-W.,Academy of Military Transportation
19th International Conference on Industrial Engineering and Engineering Management: Assistive Technology of Industrial Engineering | Year: 2013
According to the theory of neural network, a forecasting model of BP neural network is set up on the basis of studying the influencing factors of vehicle population. The forecasting accuracy is improved greatly compared with the gray forecasting model. It is valuable to enact reasonably the resource management policies and establish expropriation counterplan for freight capacity. © 2013 Springer-Verlag Berlin Heidelberg.
Wei J.,Academy of Military Transportation |
Zhao J.,Tianjin Polytechnic University
Expert Systems with Applications | Year: 2011
The optimal pricing decision problem of a fuzzy closed-loop supply chain with retail competition is considered in this paper. The fuzziness is associated with the customer demands, the remanufacturing cost and the collecting cost. By using game theory and fuzzy theory, the optimal decision on wholesale price, retail prices and remanufacturing rate are explored respectively under the centralized and the decentralized decision scenarios, and the expressions for them are also established. Some insights into the economic behavior of firms are given, which can serve as the basis for further study in the future. © 2011 Elsevier Ltd. All rights reserved.
Zhao J.,Tianjin University |
Zhao J.,Tianjin Polytechnic University |
Tang W.,Tianjin University |
Wei J.,Academy of Military Transportation
International Journal of Production Economics | Year: 2012
This paper studies the pricing problem of substitutable products in a supply chain with one manufacturer and two competitive retailers. The consumer demands and manufacturing costs are of uncertainty, which are described by fuzziness. Based on different market structures, one centralized pricing model and three decentralized pricing models are developed, and the corresponding analytical equilibrium solutions are obtained using the game-theoretic approach. Finally, numerical examples are presented to illustrate the effectiveness of the theoretical results, and to gain additional managerial insights. © 2010 Elsevier B.V. All rights reserved.
Lei D.,Tianjin University |
Lei D.,Academy of Military Transportation |
Wenjun W.,Tianjin University |
Xiankun Z.,Tianjin University |
Xiankun Z.,Tianjin University of Science and Technology
Journal of Convergence Information Technology | Year: 2012
Emergency evacuation is the movement of people away the threat in the short time. How to develop decision-making model for emergency response under dynamic conditions, to achieve the emergency evacuation plan has become a key issue. In order to improve decision-making ability of planner, a formalisation of BDIP model has been presented. In this model, the element of prediction has been extended based on the belief, desire and intention. And the accuracy and efficiency of evacuation plan can be improved through the introduction of the predictive ability of decision-maker. Accordingly, this paper indicates the extended axiom, semantics and decision-making behavior and proves the soundness and the completeness of the BDIP model. Corresponding the process and algorithm of decision-making is also given. Finally, the experiment of the decision-making process of emergency evacuation for a chlorine leakage accident is completed to validate this model.
Yang G.,Tianjin Polytechnic University |
Li Y.,Academy of Military Transportation |
Yu L.,Tianjin Polytechnic University
Diangong Jishu Xuebao/Transactions of China Electrotechnical Society | Year: 2013
Low-frequency noise can be used to measure the noise power spectrum of the LED device, Which can allow to test and analyze the defect states of the device structure in depth. This test has a good prospect, which not only has the advantages of no damage to the device and rapid measurement, but also reflects the internal characteristics of the device structure itself. This paper systematically describes the low-frequency noise generation mechanism and the mathematical model, and introduces comprehensively the research results of the 1/f and GR noise power spectral characterization based on GaN and GaAs LED devices. From the low-frequency noise characteristics of LED it can be observed that LED's performance can be tested and analyzed by 1/f and G-R noise power spectrum. And the origin affecting the life of the LED device is mainly due to dark spots in active region and defect states inside and outside the active region. The mechanism that dark spots and defect states impact the decay of LED has not yet been determined.
Zhang X.,Academy of Military Transportation |
Zhang F.,Center for Agriculture Quality and Safe |
Luo L.,Academy of Military Transportation
Applied Mechanics and Materials | Year: 2012
In this article, the authors test whether the economic growth helps predict the Dalian New Airport's cargo volume. In regression equations explaining cargo volume, the article uses various measures of economic data, including GDP, practitioner's number, waterway freight traffic volume, highway freight traffic volume, tourists. This article choices the high correlation economic indexes to build the prediction model, use the model test the previous data, verify the feasibility of the model, and forecast the Dalian New Airport's Cargo volume in the future. © (2012) Trans Tech Publications, Switzerland.