Archive

15 March 2010, Volume 31 Issue 3 Previous Issue    Next Issue
---
OriginalPaper


For Selected:

Download Citations EndNote Ris BibTeX

Toggle Thumbnails

OriginalPaper

Select

Wavelet neural networks with stable learning algorithm and its application Cong, Qiu-Mei (1); Chai, Tian-You (1); Yu, Wen (3) 2010, 31 (3):  305-308+316.  DOI: - Abstract ( 328 )   HTML   PDF (1037KB) ( 959 )   In the presence of unmodeled dynamics, the parameters' drift even instability may occur in the identification system of neural networks. Input-to-state stability(ISS) approach is applied to achieving the error backpropagation-like time-varying learning algorithm of weight matrix and wavelet scaling parameters in wavelet neural networks, of which the robust stability is guaranteed without robust modification. Simulations showed that the stable learning algorithm outperforms conventional error backpropagation ones, and the application of the algorithm to the prediction of COD in wastewater treatment process gets good results. References | Related Articles | Metrics

Select

Robust stability analysis of Cohen-Grossberg neural networks with nonnegative amplification function and multiple delays Kim, Yong-Su (1); Wang, Zhan-Shan (1); Feng, Jian (1) 2010, 31 (3):  309-312.  DOI: - Abstract ( 253 )   HTML   PDF (241KB) ( 566 )   In the process of design and implementation of Cohen-Grossberg neural networks, the nonnegative amplification function condition is very practicable. The robust asymptotic stability of a class of Cohen-Grossberg neural networks with nonnegative amplification function and multiple time delays is investigated in case of parameter perturbation. With a useful lemma proved, the relation between global asymptotic stability and robust stability is established. Then with no strictly monotonic increasing quantity and boundedness required for the activation function, a suitable Lyapunov functional is framed properly to give a sufficient and robustly stable criterion in form of linear matrix inequality (LMI) for the equilibrium point of the concerned Cohen-Grossberg neural networks. Simulation result verify the effectiveness of the conclusion. References | Related Articles | Metrics

Select

Global asymptotic stability for uncertain cellular neural networks with time-varying delays Gong, Da-Wei (1); Feng, Jian (1); Liu, Jin-Hai (1) 2010, 31 (3):  313-316.  DOI: - Abstract ( 263 )   HTML   PDF (391KB) ( 698 )   The global asymptotic stability of cellular neural networks with uncertain parameters and time-varying delays was investigated, thus giving a new criterion for stability, where the relevant uncertainties are bounded and the uncertainties of system parameters are in relation to time hence restricted in a certain range. The time delay function changes with time, and its derivative is less than 1. For such a complicated problem, there is no highly mature theory about it internationally until now. So, the model to be developed relevantly will be more general in comparison with that as shown in earlier works. Framing properly a new Lyapunov funtion and taking LMI (linear matrix inequality), the sufficient conditions are given to system stability. Two simulative examples are given to illustrate theoretically the effectiveness of the method proposed. References | Related Articles | Metrics

Select

Fuzzy control of a class of stochastic distributed parameter systems with time delay Dong, Meng (1); Hui, Guo-Tao (1); Liu, Geng-Cheng (2) 2010, 31 (3):  317-320+329.  DOI: - Abstract ( 301 )   HTML   PDF (447KB) ( 642 )   The stabilization of a class of new-type stochastic distributed parameter system (SDPS) with time delay is studied. The control of distributed parameter system (DPS) with multidimensional Brownian motion is presented on the basis of Galerkin's method and fuzzy theory. Then, some criteria, i.e., the sufficient conditions, for the asymptotical stability of the system in form of mean square are given by linear matrix inequality (LMI), which can easily be checked by Matlab toolbox. A simulative example is given to show the effectiveness of the proposed method. References | Related Articles | Metrics

Select

Design of multi-objective fuzzy dynamic output feedback controller Chen, Zhao-Na (1); Zheng, Yan (1); Jing, Yuan-Wei (1) 2010, 31 (3):  321-325.  DOI: - Abstract ( 270 )   HTML   PDF (304KB) ( 501 )   The design of a H∞ dynamic output feedback controller, satisfying the configuration of closed-loop poles was studied for a class of uncertain T-S fuzzy dynamic systems, via linear matrix inequalities (LMIs). The control laws are in the form of so-called dynamic parallel distributed compensation (DPDC) which is essentially for the design of nonlinear dynamic feedback controllers. Such a design is more general than previous ones since the parameter uncertainties in controlled output variables and the non-zero control coefficients of controller are both taken into account. Then, the sufficient condition is given to the global stability of closed-loop fuzzy systems with the condition transformed into LMI form. The effectiveness of the proposed approach is successfully verified through an example of complex nonlinear Chen's system by means of the numerical simulation. References | Related Articles | Metrics

Select

Global sliding mode control for nonlinear network systems with input restriction Wang, Hong-Wei (1); Yu, Chi (1); Jing, Yuan-Wei (2) 2010, 31 (3):  326-329.  DOI: - Abstract ( 321 )   HTML   PDF (612KB) ( 704 )   An active queue management (AQM) algorithm based on global sliding mode control was designed to cancel the arrival stage of sliding mode control so as to solve the problem of dynamic TCP network congestion with inputs restricted, thus ensuring the robustness of network system in the whole control process. The algorithm shows its good transient/steady state responses in TCP/IP networks, such as modeling uncertainties, fluctuation of time-varying parameters and network jittering due to non-TCP sessions. Simulation results revealed that this method enables the queue length to converge at its set value quickly with the queue fluctuation kept low. In particular, the algorithm proposed outperforms the conventional PI control and sliding mode control if the network conditions are changed. References | Related Articles | Metrics

Select

Anamorphic visual image rectification method based on robust pick-up of control points Liu, Jun (1); Hu, Zhen-Wei (1); Zhang, Da (1); Xie, Zhi (1) 2010, 31 (3):  330-333.  DOI: - Abstract ( 461 )   HTML   PDF (1545KB) ( 1040 )   It is hard to rectify accurately the dynamic images online because of the big errors resulting from the difficult automatic pick-up of control points in the rectification process of unavoidable anamorphic images by camera. Taking account of the limitation of existing pick-up methods, an approach to well-matched high robust pick-up of control points was proposed for the rectification, which can implement the automatic, accurate and robust pick-up of control points through developing a polynomial mapping model with optimum polynomial degree for both anamorphic and original images, thus rectifying those images via bilinear interpolation. The application results show that the method can rectify the image quickly and accurately. It can yield accurate correction results of which error is only 0.037 pixel. References | Related Articles | Metrics

Select

A target tracking method of rescue system for buildings during disaster Jia, Zi-Xi (1); Wu, Cheng-Dong (1); Zhang, Yun-Zhou (1); Huang, Yue (1) 2010, 31 (3):  334-337.  DOI: - Abstract ( 272 )   HTML   PDF (599KB) ( 743 )   In the research on target tracking, lots of experimental results illustrated that the particle filter algorithm is imperfect to the moving target of which the trajectory changes complexly. The AVRPF (adaptive variable rate particle filter) algorithm is proposed instead of VRPF (variable rate particle filter) algorithm in regard to the rescue system for large-scale building during disaster, with the wireless sensor network technology applied to the system. The AVRPF can adaptively adjust the sampling period by comparing the relationships between the particle value and measured value at a certain moment to improve the tracking accuracy for complex moving target, especially the moving trajectory changes dramatically. The simulation results showed that the tracking algorithm is effective and practical. References | Related Articles | Metrics

Select

An uncertain skyline query algorithm based on state space searching Xin, Jun-Chang (1); Huang, Jian-Mei (1); Wang, Guo-Ren (1); Gong, Pi-Zhen (1) 2010, 31 (3):  338-341.  DOI: - Abstract ( 355 )   HTML   PDF (427KB) ( 672 )   The skyline query processing technique about an uncertain databases is discussed in depth because only a single object is considered as the constitution of skyline with the integrality ignored in the threshold query of the whole skyline. A new concept of uncertain skyline query is therefore redefined gathering all the skyline objects as a whole in view of probability. A state space searching based on BUS (basic uncertain skyline) query algorithm is proposed after analyzing its properties. Then, a novel algorithm IUS (improved uncertain skyline) is given through efficient filtering strategy to improve BUS. Experimental results showed that the performance of IUS is obviously superior to BUS, thus verifying the effectiveness of improving strategy. References | Related Articles | Metrics

Select

Security analysis of a class of selective image encryption scheme Zhu, Zhi-Liang (1); Zhang, Zhi-Qiang (1); Gao, Jian (1); Yu, Hai (1) 2010, 31 (3):  342-345.  DOI: - Abstract ( 341 )   HTML   PDF (1058KB) ( 593 )   The security of a class of selective encryption scheme was analyzed. According to the characteristics of the correlation of adjacent image pixels, an algorithm to attack the encryption scheme was given using the disclosed information from cipher text and the method of known-plaintext attack, and the validity of the algorithm was verified by experiments. The experimental results showed that the higher the correlation of adjacent pixels of an image, the less the plaintext available to recover more information in plaintext by use of not encrypted information in cipher text. Therefore, for an image which has a high correlation between adjacent pixels, the selective encryption scheme is unsecured. The selective encryption scheme is thus correspondingly. References | Related Articles | Metrics

Select

A community discovery method based on breadth-first-search Chen, Dong-Ming (1); Xu, Xiao-Wei (2) 2010, 31 (3):  346-349.  DOI: - Abstract ( 305 )   HTML   PDF (1149KB) ( 790 )   In view of the existing algorithm that is unable to take better account of the network connectivity and the attributes of individual nodes comprehensively, the limitation of the typical algorithms of agglomerative and divisive clustering was analyzed, thus defining conceptually the edge loading, edge weight, connectivity threshold and graph segmentation. Then, a new algorithm SoNetCD based on BFS(breadth-first-search) is presented for discovering the communities in social networks, which takes both network topology and edge weight into consideration. Inter-community edges are cancelled to reveal the community structure in the algorithm, thus judging exactly the inter-community and lowering the failure rate of cancelling inner-community edges. Experimental results of a real-world social network dataset showed that the SoNetCD outperforms the typical GN algorithm in identifying community structure. References | Related Articles | Metrics

Select

Traffic-based load balancing routing protocol in ad hoc network prediction Sha, Yi (1); Zhang, Ting (1); Chen, Jin (1); Wang, Guang-Xing (1) 2010, 31 (3):  350-353.  DOI: - Abstract ( 299 )   HTML   PDF (496KB) ( 817 )   Proposes a traffic-based load balancing routing protocol (T-LBRP), where the traffic load is computed according to the interface queue length of MAC layer, with the average network load defined as the threshold value. The idea of dynamic threshold is introduced to judge if an intermediate node is overloaded in the route discovery phase. Then, the RREQ messages are forwarded selectively according to the load status of each node so as to prevent heavily loaded nodes from routing. At the destination node, the response messages along the optimum lightly loaded route are selected via delayed response. Simulation results proved that the T-LBRP can raise the delivery ratio by about 7%, with the end-to-end delay and normalized routing reduced by about 25% and 45%, respectively, in comparison with conventional protocols. References | Related Articles | Metrics

Select

Sensor localization with ring overlapping based on RSSI using three beacons Qu, Wei (1); Wang, Jin-Kuan (1); Liu, Zhi-Gang (1) 2010, 31 (3):  354-357.  DOI: - Abstract ( 262 )   HTML   PDF (673KB) ( 685 )   For the localization of nodes in WSN, a new sensor localization approach based on ROBRSSI(ring overlapping based on received signal strength indicator) using three beacons was presented. Designing the handling of error transforming and the collaboration between unknown nodes and their two-hop neighbors, the effect of measurement error of RSSI on localization accuracy as shown in earlier works is restrained efficiently with the requirement for the relative position between node and beacons reduced to implement the node's precise localization. Then, the localization of new comers in WSN is studied on the basis of ROBRSSI. Simulation results showed the validity and superiority of the algorithm. References | Related Articles | Metrics

Select

Medical image retrieval based on gray level co-occurrence matrix and gradient phase mutual information Zhi, Li-Jia (1); Zhang, Shao-Min (1); Zhao, Da-Zhe (1); Zhao, Hong (1) 2010, 31 (3):  358-361+365.  DOI: - Abstract ( 294 )   HTML   PDF (1227KB) ( 986 )   A new two-step medical image retrieval algorithm for clinical practice was proposed combining the gray level co-occurrence matrix with gradient phase mutual information. Based on the good classification performance of gray level co-occurrence matrix, the algorithm refines the retrieved process to improve its precision and the integral robustness of the retrieval algorithm. With the algorithm applied to 6 different anatomical positions of CT images, the testing results showed that the algorithm can provide high precision while attaining near real-time speed of response to queries. Expanding properly the algorithm, it can be easily applied to clinical practice in wider fields. References | Related Articles | Metrics

Select

Effects of control cooling on mechanical properties of C-Mn steel Zhou, Xiao-Guang (1); Liu, Zhen-Yu (1); Wu, Di (1); Wang, Guo-Dong (1) 2010, 31 (3):  362-365.  DOI: - Abstract ( 222 )   HTML   PDF (1377KB) ( 591 )   The effects of cooling rate on both austenite grain size and ferrite grain size at room temperature before ferrite transformation were investigated on MMS-300 thermomechanical simulator with the specimens of a kind of C-Mn steel to which the trial rolling processes were done simultaneously on rolling mills with conventional low-temperature controlling and non-low temperature controlling plus forepart fast cooling technologies. Some results revealed that: (1) the austenite grain size decreases with the increasing cooling rate before ferrite transformation; (2)the ferrite grain size at room temperature becomes finer with the increasing cooling rate before ferrite transformation; (3)the excellent mechanical properties provided by the technology of non-low temperature controlling rolling plus forepart fast cooling are the same to that by the low-temperature rolling technology, but the former has lower yield/tensile ratio. References | Related Articles | Metrics

Select

Effect of two-step cold rolling on deep drawability and texture of ferritic stainless steel Du, Wei (1); Liu, Zhen-Yu (1); Jiang, Lai-Zhu (2); Sun, Quan-She (2) 2010, 31 (3):  366-369.  DOI: - Abstract ( 305 )   HTML   PDF (773KB) ( 604 )   The effects of one-step and two-step cold rolling schedule on deep drawability and texture of ferritic stainless steel were investigated comparatively. The results showed that the high average plastic strain ratio rm=1.92, especially the diagonal r-value at 45° which is higher than either longitudinal or transverse r-value were achieved after the one-step cold rolling with a percentage reduction up to 90%. Thus, the value of planar anisotropy parameter Δr becomes negative, i.e., Δr=-0.31. With the total reduction kept constant, the average r-value of the sheet as the products from the two-step cold rolling fluctuates little(rm=1.90) with Δr=0.14, a very small value. The analysis results of recrystallization texture revealed that in the sheet from one-step cold rolling an intensified γ texture forms, and its peak value deviates from {111} axial orientation but shift to the orientation {223}<582>. However, in the sheet from two-step cold rolling a homogeneous γ recrystallization texture forms. References | Related Articles | Metrics

Select

Effect of UFC technology on structure property of medium/low carbon steel Fu, Tian-Liang (1); Deng, Xiang-Tao (1); Wang, Zhao-Dong (1); Cui, Dong-Liang (2) 2010, 31 (3):  370-373+393.  DOI: - Abstract ( 393 )   HTML   PDF (1462KB) ( 1465 )   Based on the UFC-ACC design idea and combining the UFC mechanism with its cooling technological applications in medium/heavy plate production, an optimal UFC schedule was given including different rolling processes with the plates' mechanical properties changed after UFC analyzed. Comparing the metallographic structures obtained from different technological processes and combining them with theoretical calculation, how the structure property of medium/low carbon steel evolves due to UFC was discussed and summarized. It was found that the impact toughness of medium/low carbon steel increases obviously in addition to other mechanical properties which are also improved. What is more, most of the steel structure is homogeneous and fine F+P grains after UFC-ACC cooling with the high dislocation density in original austenite kept on, thus making the steel performance treated by UFC-ACC better than that just treated by conventional ACC cooling. References | Related Articles | Metrics

Select

Microstructure transformation in tempering process of low-temperature pressure vessel steel Chen, Bing-Zhang (1); Chen, Yong-Li (1); Zhu, Fu-Xian (1); Gong, Wen-Xu (2) 2010, 31 (3):  374-377.  DOI: - Abstract ( 265 )   HTML   PDF (1299KB) ( 504 )   The 07MnNiMoVDR steel for low-temperature pressure vessel was investigated via thermal expansion testing in combination with TEM detection for the transformation of microstructure between different temperature intervals and change of carbide precipitation in the tempering process. The results showed that when the specimens are tempered at 300°C the residual austenite is decomposed and the lamellar θ-carbides are found between α-phase laths which are still of relatively high dislocation density. When tempered at 650°C, the α-phase laths are recovered with part of them recrystallized. Moreover, the precipitates are distributed between the recovered α-phase laths and on the recrystallized grain boundaries. References | Related Articles | Metrics

Select

Application of extended Kalman filter to pass modification in plate rolling Xu, Lei (1); Zeng, Qing-Liang (1); Cui, Hai-Tao (1); Wang, Guo-Dong (1) 2010, 31 (3):  378-380+384.  DOI: - Abstract ( 314 )   HTML   PDF (629KB) ( 937 )   It has been indisputable that the high-precision gauge control should be acquired via steady on-line modification of pass or roll gap. The application of extended Kalman filter to pass modification indicated that it is able to not only solve the feedback data-processing problem, but also provide a more accurate prediction model for every updating of pass reduction. The prediction model can predict accurately the key parameters in rolling process by the linearized derivation of main models of rolling process, thus calculating the modifying values of subsequent passes with those key paramenters. The on-line application results in ANSTEEL indicated that the gauging rate increases by 14.2% for heavy paltes. References | Related Articles | Metrics

Select

Head splits of BT303CuS free-cutting stainless steel workpieces during rolling Ma, Bao-Guo (1); Xu, Song-Qian (2); Zhao, Su-Wu (2); Liu, Xiang-Hua (1) 2010, 31 (3):  381-384.  DOI: - Abstract ( 295 )   HTML   PDF (917KB) ( 638 )   The causes of head splits of a workpiece in hot rolling process of free-cutting stainless steel were analyzed. It was found that there is a relationship between the head splits and morphology of sulphides in the steel. A thermomechanical simulation test was therefore carried out to investigate the effect of reheating temperature on the sulphide morphology, and the optimum range of reheating temperature was determined as 1200~1280°C. Then, some measures were taken to get rid of the heat splits, such as controlling the cooling water at the workpiece head, using the new-type guide/guard system and adding a flying shear to cut the workpiece head. Thus, the intermediate rejection rate was decreased from 5.67% to 1.38%. Now the different rolled products of BT303CuS steel has come into batch production in Baoshan Iron & Steel Co., Ltd.. References | Related Articles | Metrics

Select

Analysis of abnormal segregation band of X100 pipeline steel Zhou, Min (), Yi, Hai-Long (), Du, Lin-Xiu (), Liu, Xiang-Hua () 2010, 31 (3):  385-388+410.  DOI: - Abstract ( 435 )   HTML   PDF (2122KB) ( 792 )   Metalloscope, SEM and EDS (energy density spectrum) were used for the abnormal segregation band of X100 pipeline steel to observe its structure and analyze the composition linearly scanned fracture due to tension/impact and inclusions. The results indicated that the microstructure of the segregation band is polygonal ferrite with mixed crystal of which the sizes of some grains are different from each other, and the microstructure is greatly different from the matrix microstructure which is mainly the lath bainite. In the segregation band the carbon content is relatively low, while the manganese, silicon and oxygen contents are all relatively high. The layered fracture due to tension/impact is found around the center or at the quarter of the sectional thickness of the fracture, and an inclusion band is observed at the quarter of the whole thickness of impact fracture, where part of some inclusions are flaky. The impact toughness of specimens is thus seriously deteriorates. References | Related Articles | Metrics

Select

Analysis of UPC in BF coal injection process Wang, Zhu-Min (1); Lü, Qing (2); Wang, Lei (2) 2010, 31 (3):  389-393.  DOI: - Abstract ( 300 )   HTML   PDF (789KB) ( 1250 )   The utilization of coal injection was analyzed by testing the burning rate of coal injected into the BF in HANSTEEL. The carbon content of dust from BF was determined via lithofacies analysis made to differentiate the structure of UPC from that of the coke in dust, thus determining the source of carbon-bearing substances in BF dust. The results showed that the BF dust contains comparatively high carbon content, among which the UPC particles are in three forms: slightly changed coal, porous coal and redidual carbon particles. And the structure of coke particles can be divided into filament-like, granular mosaic, flowing, flake-like and blocky textures. According to what coal is used and mixed for the BF in HANSTEEL at present, some suggestions are given to improve efficiently the burning rate of pulverized coal in HANSTEEL, and the coal from Changzhi/Dawan is preferable to mixed coal injection. References | Related Articles | Metrics

Select

Effects of carbon ratio on softening-dripping behavior of carbon composite iron ore hot briquette Chu, Man-Sheng (1); Liu, Zheng-Gen (1); Wang, Zhao-Cai (1); Fu, Lei (1) 2010, 31 (3):  394-397.  DOI: - Abstract ( 369 )   HTML   PDF (1282KB) ( 727 )   Effects of carbon ratio (n(FC)/n(O)) on the softening-dripping behavior of carbon composite iron ore hot briquette (CCB) were studied systemically and theoretically, with the basicity 1.20 unchanged. The results showed that the carbon ratio affects greatly the softening-dripping parameters, such as softening range, melting range and dripping ratio. With the increasing carbon ratio, the softening range t40~t4 tends to narrowing then widening, and becomes the narrowest (348°C) at the carbon ratio 1.00. The melting range tD~tS also tends to narrowing then widening, and becomes the narrowest (46°C) at the carbon ratio 1.00. The dripping ratio tends to increasing then decreasing, which comes up to its highest value (24.66%) at the carbon ratio 1.08. Taking account of the softening-dripping behavior comprehensively, the carbon ratio appropriate to actual production of CCB should be set around 1.00. References | Related Articles | Metrics

Select

CFD-based numerical simulation of steam ejector and its performance Zhang, Qi (1); Huo, Jie-Peng (1); Wang, Ru-Wu (3); Wang, Yuan (3) 2010, 31 (3):  398-401.  DOI: - Abstract ( 364 )   HTML   PDF (975KB) ( 979 )   Based on the construction of an ejector, a 2-D CFD model of the steam ejector was developed to investigate the influence of its operating parameters including operating, driving and mixed fluid pressures and constructional parameters including the length of contraction section of mixing chamber, length and diameter of second throat, length of diffusion chamber and construction of primary nozzle on the performance of a steam ejector. Simulation results indicated that the optimal or maximum jet coefficient depends on the length and diameter of second throat, diameter of primary nozzle throat and the area ratio of primary throat to nozzle throat (φ). CFD is thus proved a powerful tool to predict the properties of ejector and, what's more, it can be used to make sure of the flowing/mixing process of the fluid in ejector. References | Related Articles | Metrics

Select

Metallurgical behavior of inclusions in 304 austenitic stainless steel Li, Shuang-Jiang (1); Li, Yang (1); Jiang, Zhou-Hua (1); Li, Wei-Jian (1) 2010, 31 (3):  402-405.  DOI: - Abstract ( 552 )   HTML   PDF (1290KB) ( 1427 )   Combining the thermodynamic calculation with industrial production, the variation of inclusions in 304 austenitic stainless steel deoxidized by silicon alloy during LF refining and continuous casting process was investigated. The results showed that the inclusions formed in molten steel are mainly CaO-Al2O3-SiO2 compounds, and the Al content decrease gradually with Si reduction. In the process of LF refining and continuous casting process when the refining slag basicity was controlled at 1.5, the Al2O3 content in the compounds decreases gradually together with CaO and SiO2 contents increasing. The contents of compounds in the final billet are 30%~35% CaO, 20%~27%Al2O3 and 25%~30% SiO2 with other oxides relatively less. The deformability of the billet is relatively low, and the inclusions in it are slightly alkaline. References | Related Articles | Metrics

Select

Effects of compaction methods on cell structures of closed-cell aluminum foams Wang, Lei (1); Yao, Guang-Chun (1); Ma, Jia (1); Hua, Zhong-Sheng (1) 2010, 31 (3):  406-410.  DOI: - Abstract ( 276 )   HTML   PDF (1666KB) ( 876 )   Aluminum foams were successfully prepared by a powder metallurgy method with commercially pure Al powder, Mg powder and TiH2 powder as raw materials. The effects of cold uniaxial compacting pressures on cell structures of aluminum foams with fully lubricated dies and the effects of cold/hot compaction and sintering after cold compaction under the pressure 400MPa on the cell structures and quasi-static compressibility of aluminum foams were both investigated via a scanner with the resolution of 300dpi, SEM and universal testing machine. The results revealed that the high-quality precursors are available by uniaxial cold compaction under the pressure 400MPa with aluminum foams provided as finish products of uniformly distributed cell structures and identical compressibilities. References | Related Articles | Metrics

Select

Cycling thermal shock resistance of Ti-Al-Cr coating deposited on Ti60 alloy by arc ion plating Yan, Wei (1); Sun, Feng-Jiu (1); Liu, Jian-Rong (2); Liu, Jie (3) 2010, 31 (3):  411-414.  DOI: - Abstract ( 286 )   HTML   PDF (2179KB) ( 746 )   The Ti-48Al-5Cr and Ti-48Al-12Cr(in at%) coatings were both deposited on Ti60 alloy surface via arc ion plating process. The cycling thermal shock resistances of uncoated specimens and that coated with Ti-Al-Cr coating were investigated at the temperature between 900/950°C and room temperature by forced water cooling. The mass change, phase composition and surface/cross-section morphology of specimens were all discussed. The results showed the Ti-48Al-12Cr coating exhibited high resistance of thermal shock, thus protecting efficiently the Ti60 alloy as substrate. However the Ti-48Al-5Cr coating cannot protect the substrate efficiently because of the less Cr content which results in different oxidation mechanism. The cycling test results revealed that the shock will expedite the spalling and break-up of oxides, thus expediting the occurrence of internal oxidation and the initiation/propagation of cracks. References | Related Articles | Metrics

Select

Research on resonance characteristics of nonlinear suspension system of motor vehicles Feng, Fei (1); Li, Ling-Xuan (1); Chen, Ya-Zhe (1); Wen, Bang-Chun (1) 2010, 31 (3):  415-417+426.  DOI: - Abstract ( 351 )   HTML   PDF (678KB) ( 1315 )   A 2-DOF nonlinear dynamic model was developed with a differential equation of motion involving cubic nonlinear stiffness given for motor vehicles and the amplitude-frequency response was solved by the method of multiple scales. A numerical simulation was done to reveal the amplitude-frequency response of the nonlinear suspension system involving different nonlinear parameters when there is a simultaneous coexistence including the main, superharmonic, subharmonic, and internal combination resonance. The results showed that the nonlinear parameters should be chosen reasonably so as to get rid of the possible instabilities of suspension system such as skipping and bifurcation, thus controlling efficiently the vibration of motor vehicles. References | Related Articles | Metrics

Select

Computer simulation of noise from intake system of diesel engine Yue, Gui-Ping (1); Zhang, Yi-Min (1) 2010, 31 (3):  418-421.  DOI: - Abstract ( 335 )   HTML   PDF (936KB) ( 645 )   The noise from intake system of diesel engine is the most important noise source of a top-grade commercial vehicle, especially its interference inside the vehicle. Based on the theory of pipeline acoustics and flow resistance analysis, an approach named non-source method was proposed to simulate the noise from diesel engine so as to solve the problem that the acoustic simulation of intake system is so hard to carry out, i.e. no way will the geometrical/physical parameters be obtained though they are necessary to the simulation model of an engine. With the non-source method applied to the solution of such a problem, the computer simulation can be done without a relevant simulation model of noise from intake system. Then, both the noise and power loss of the engine can be predicted to provide a reference for the rapid and accurate acoustic optimization of engine's intake system. References | Related Articles | Metrics

Select

Analysis and representation of ontology-based business process knowledge in workshop Shi, Chun-Jing (1); Hao, Yong-Ping (2); Liu, Yong-Xian (1) 2010, 31 (3):  422-426.  DOI: - Abstract ( 268 )   HTML   PDF (2282KB) ( 767 )   How to effectively utilize the existing business processes is crucial to the study on workshop production management. Introducing the ontology into the workshop business process management, the framework and representation of process knowledge were discussed. A meta-model of workshop operation was developed ontologically through analyzing the workshop process model, then the meta-model was described in formalized representation to develop an ontological workshop model with the process flow as the center. For the business process of a particular job in workshop, it was represented by the ontological modeling language OWL, thus verifying if the ontological workshop model is adaptable to the representation and shareability of the knowledge of workshop process. The result showed that this method can conveniently implement the ontological representation of the existing business processes in workshop. References | Related Articles | Metrics

Select

Version management model of collaborative design based on theory of polychromatic sets Hou, Shou-Ming (1); Liu, Yong-Xian (1); Guo, Chen-Guang (1); Yu, En-Chao (1) 2010, 31 (3):  427-431.  DOI: - Abstract ( 322 )   HTML   PDF (1894KB) ( 546 )   To meet the requirements of hierarchical version management in the process of collaborative design, a new version management model based on the theory of polychromatic sets was developed, with the concept and method of the theory introduced. In this model, the elements of the polychromatic sets, uniform color and individual colors represented the parts/assemblies and their versions, the integrated attribute of the objects to be designed and the individual attributes of the componential elements and their versions of those objects, respectively. Then, with an exemplification of the hierarchical versions of the design of turbine blades, the expressions in Boolean matrices of versional architectural information, attributes and attribute relationship between versions were given. As a result, the model is available not only to describe easily the history of version revision in the process of collaborative design, but also to express the restrictive relation between versions that were configured differently. Moreover, the model is easy to expand so as to facilitate programming. References | Related Articles | Metrics

Select

A multi-scale edge detection method of steel strip surface defects online detection system Zhao, Jiu-Liang (1); Yan, Yun-Hui (1); Liu, Wei-Wei (2); Tong, Jian (1) 2010, 31 (3):  432-435.  DOI: - Abstract ( 454 )   HTML   PDF (2139KB) ( 732 )   The image edge of steel strip surface defects cannot be detected exactly on-line at present. It is a serious problem to be solved. A wavelet-based maximum modulus algorithm is therefore proposed for edge protection, which can coordinate well the edge detection precision and denoising effect to extract the surface defect edges on multi-scale. Experimental results showed that the new algorithm can exclude well the fault detect edge from detection with the particulars of defect edge kept up, thus providing better edge detectivity for the subsequent online processing in surface defect detection, such as image auto-segmentation, defect identification, etc. References | Related Articles | Metrics

Select

Multi-attribute decision-making model based on connectivity distance of generalized weight Li, De-Shun (1); Xu, Kai-Li (1); Han, Ning-Bo (2); Wang, Zhen-Quan (1) 2010, 31 (3):  436-439.  DOI: - Abstract ( 305 )   HTML   PDF (211KB) ( 748 )   For the uncertainty problem of multi-attribute decision-making, the set pair analysis was made to deal with both the certainty and uncertainty problems. In view of the dialectic relation between certainty and uncertainty, the schemed index set and ideal index set were taken as a set pair to define the connectivity distance of generalized weight between all other schemes and the positive scheme as well as the distance between all other schemes and the negative schemes. Discusses the present applications of the set pair analysis in multi-attribute decision-making, with the deficiency in applications pointed out. Then a multi-attribute decision-making model was proposed on the basis of connectivity distance of generalized weight, and it was applied to the optimum decision of mine equipment. The results showed that the model is adaptable to multi-project optimization, thus providing a new way to the multi-attribute decision-making. References | Related Articles | Metrics

Select

Research on grouting effect on tunneling with FLAC3D Li, Shen-Gang (1); Zhao, Wen (1); Wang, Cheng (1); Cai, Xiao-Li (2) 2010, 31 (3):  440-443.  DOI: - Abstract ( 562 )   HTML   PDF (1629KB) ( 1394 )   The stress distribution and evolving surface settlement during tunneling and excavating surrounding rockmass after grouting were studied with FLAC3D for the change in the mechanic properties of grouted surrounding rockmass. The simulation results in contrast to engineering practice indicated that the grouting serves the function of shielding to reinforce tunneling and both sides of reinforced rockmass are the stress concentration area. With the 3/4 part(270°) of a circular hole used for grouting, the settling amount due to excavation in simulation is minimum, i.e. 22.3mm which becomes 27.1mm in practical monitoring. Therefore, it is feasible to forecast the reinforcement effect by simulation with FLAC3D. The reason why the simulated settling amount deviates from that monitored relates to the idealized grouting construction. It's of importance to increasing the grouting pressure gradually and to judging whether the grouting process should be ended according to both the finishing pressure and grouting amount so as to ensure the grouting quality. References | Related Articles | Metrics

Select

Analysis of lasting monitoring results for design/construction of supporting system of a deep foundation in shenyang Zhang, Jun (1); Zhu, Fu-Sheng (1); Wang, Zhu (2); Fu, Dian-Wu (3) 2010, 31 (3):  444-447.  DOI: - Abstract ( 261 )   HTML   PDF (1724KB) ( 1050 )   A lasting in-situ monitoring was done to investigate the design of the supporting system for a very deep foundation pit in Shenyang. The results showed that the design applying an anchor pile system to the foundation pit is feasible on the whole, though the anchor piles are overdeformed somewhat, thus resulting in insufficient safty factors. Taking appropriate measures is therefore necessary to improve the safty of anchor pile supporting system for similar foundation projects. The excavation for a subway tunnel in the vicinity of the foundation pit affects the pit little, so it is negligible in the design of such a supporting system. However, the effects of frost heaving of foundation soil on the stability of foundation pit is innegligible, which is an important factor must be taken into account in winter for the foundation pit projects in Shenyang. The analysis of the monitoring results is available to provide the reference for both the design and construction of very deep foundation pit projects in Shenyang. References | Related Articles | Metrics

Select

A method based on dominance probability for stochastic multiple attribute decision making Jiang, Guang-Tian (1); Fan, Zhi-Ping (1); Zhang, Xiao (1); Liu, Yang (1) 2010, 31 (3):  448-450+456.  DOI: - Abstract ( 216 )   HTML   PDF (246KB) ( 1020 )   Proposes a method based on dominance probability for SMADM with random variables. The dominance probability of pairwise comparison of alternatives is defined and calculated to frame a dominance probability matrix, where both attributes of the alternatives are taken into account. Then, the PROMETHEE II method is used to result in ranking the alternatives. The proposed method is clear in concept and easy to calculate, thus solving well the problem of possible data loss due to the method based on stochastic dominance criterion. A numerical example is taken to illustrate the feasibility and validity of the proposed method. References | Related Articles | Metrics

Select

SEM-based evaluation of corporate social responsibility for labor relations in china Zhang, Lan-Xia (1); Wu, Xiao-Kang (1); Chen, Tao (1); Pu, Yong-Qing (1) 2010, 31 (3):  451-456.  DOI: - Abstract ( 280 )   HTML   PDF (2539KB) ( 947 )   Based on the recent researches, an evaluation index system was formulated to CSR for the labor relations in China via interviews and questionaire or other ways, including 2 first-level, 11 second-level and 52 third-level indexes. The index system was composed of two parts, i.e., the CSR based on explicit contract and that on implicit contract. Then, a CSR evaluation model was developed for China's labor relations on the basis of SEM, by which the CSR performance of labor relations was evaluated for three Chinese firms, i.e., the Northeast Electric Power Co., Neusoft Group and Baosteel Group, thus showing the effectiveness of the evaluation index system. References | Related Articles | Metrics