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15 November 2007, Volume 28 Issue 11 Previous Issue    Next Issue
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Non-fragile H∞ control for a class of T-S fuzzy descriptor systems Zhang, Yan (1); Zhang, Qing-Ling (1); Li, Qin (1) 2007, 28 (11):  1521-1524.  DOI: - Abstract ( 232 )   HTML   PDF (1915KB) ( 553 )   The design problem of H∞ state feedback controller with variable gains from feedback is studied in state space for a class of T-S fuzzy descriptor systems, i.e., the controller can stabilize the systems and satisfy the H∞ performance even if the controller is perturbed externally. Making use of the theory of Lyapunov stability and linear matrix inequality (LMI), the sufficient conditions are given to the existence of the desired non-fragile H∞ controllers for a class of T-S fuzzy descriptor systems, with the design method of the controller presented. A numerical simulation is done to show the feasibility and effectiveness of the proposed method. References | Related Articles | Metrics

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Determination of optimal revs of piercer's guide disc Pan, Xiao-Li (1); Xiao, Dong (1); Mao, Zhi-Zhong (1); Wang, Fu-Li (1) 2007, 28 (11):  1525-1528.  DOI: - Abstract ( 264 )   HTML   PDF (290KB) ( 655 )   Piercer is an integral equipment to seamless steel tube rolling, to which the problem that a pause is necessary when readjusting rolling parameter is unsolvable for long, thus reducing the productivity greatly. Nowadays the BaoSteel has implemented the on-line readjustment of an important rolling parameter, i.e., the guide disc revs, by rebuilding the Diescher guide disc on SWW skew rolling piercer. Describes the way to rebuild the Diescher guide disc and, based on ICA, the ICR is introduced in solving the optimal revs of the disc. A model is developed for the optimal revs of the disc. Test results show that the optimal revs given by the model can improve both product quality and productivity effectively with energy saving realized. References | Related Articles | Metrics

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Fault diagnosis based on grey clustering algorithm for hydraulic tube tester Hu, Xue-Fa (1); Zhao, Zhen (1); Wang, Fu-Li (1); He, Da-Kuo (1) 2007, 28 (11):  1529-1532.  DOI: - Abstract ( 222 )   HTML   PDF (728KB) ( 575 )   Pressure testing in hydraulic tube tester may induce a wide range of possible failures to reduce productivity, and it is hard to find locations and reasons when they happen. An improved grey clustering algorithm is therefore presented to cluster the data of hydraulic tube tester by selecting the data reflecting real production, then the expert system is used to diagnose the results of this improved grey clustering algorithm. This approach is applied to the #3 hydraulic tube tester in a corporation. The experiment results demonstrated that the accuracy can be improved effectively through this new approach. References | Related Articles | Metrics

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Study on a morphological gradient toboggan algorithm Guo, Li (1); Gao, Li-Qun (1); Wang, Kun (1); Pian, Zhao-Yu (1) 2007, 28 (11):  1533-1535.  DOI: - Abstract ( 309 )   HTML   PDF (265KB) ( 561 )   Toboggan algorithm is an important tool to image segmentation, and the result of image segmentation depends on how to compute the gradient image to a great extent if applying toboggan to it. A multiscale morphological gradient toboggan algorithm is proposed to obtain the gradient image by characterizing the structural elements of different sizes and then segment the image. To reduce the over-segmentation of toboggan, a merging method of regions is carried out after toboggan segmentation according to their areas and similarities. Test results show that the algorithm is valid and more accurate than other conventional algorithm in image segmentation, especially it has a wider scope of application because of the selective flexibility of structural element shape and size. References | Related Articles | Metrics

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Study on morphological corner detection for scenery image Chang, Xing-Zhi (1); Gao, Li-Qun (1) 2007, 28 (11):  1536-1539.  DOI: - Abstract ( 215 )   HTML   PDF (479KB) ( 537 )   Introducing the symmetry of circular operator, an improved morphological detection algorithm is proposed for binary images to avoid the rotation of structural elements so as to raise the detection efficiency. Then, an improved method for EM image segmentation is proposed for gray and color images to enhance the regional features after segmentation, thus providing more reasonable conditions morphologically for the corner detection of gray and color images. Experimental results verified that the method can get better detection result even if the corner detection is done in a noisy or complex background. References | Related Articles | Metrics

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Modeling and analysis of using CDC-based benign worms to counteract worms Zhou, Han-Xun (1); Zhao, Hong (2) 2007, 28 (11):  1540-1543.  DOI: - Abstract ( 313 )   HTML   PDF (247KB) ( 860 )   According to the idea about constructing a CDC (center for disease control), the deployment and response mechanism of CDC-based benign worms are designed, with the process of using CDC-based benign worms to counteract the propagation of worms modeled and simulated. Then, the two influencing factors on the process are revealed through the simulation, i.e. the response time and detection rate of worm by probe. The propagation model of CDC-based benign worms can provide a better understanding and prediction for the scope and speed of using benign worms countering against the propagation of worms. References | Related Articles | Metrics

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Application-oriented web service discovery and matchmaking Ye, Lei (1); Zhang, Bin (1) 2007, 28 (11):  1544-1547.  DOI: - Abstract ( 310 )   HTML   PDF (243KB) ( 850 )   The aim of application-oriented web service discovery is to enable customers to find out the suitable web services so as to support functionally the building of application systems, thus reducing cost and improving efficiency. But in the current way the demand cannot be met very well. A web service discovery based on functional semantics is therefore proposed to define the functional semantic model that provides a unified description of web service for both service providers and customers. Meanwhile, depending on the semantic annotation mechanism of the body statements of functions in application domain, the semantic ambiguity in service description can be eliminated. Then, a strategy is proposed further to match web service discovery with what are required by functional semantics. Experimental results showed the validity of the method proposed. References | Related Articles | Metrics

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A local clustered evolving network model Zhao, Hai (1); Yuan, Shao-Qian (1); Zhang, Xin (1); Li, Chao (1) 2007, 28 (11):  1548-1551.  DOI: - Abstract ( 279 )   HTML   PDF (967KB) ( 634 )   The famous local-world model has presented a notion about local evolving, but the methodology it selected dose not conform to the reality very well. So, a modified version of the local-world evolving model is presented, with which the network generated possesses both the scale-free and small-world properties, and it's degree distribution represents a transition between power-law and exponential scaling. In contrast to the old model, it has a much bigger cluster coefficient which is in conformity with the real world, thus making the modified model more applicable than the old one. References | Related Articles | Metrics

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A WSNs OS kernel with energy management mechanism Luo, Ding-Ding (1); Zhao, Hai (1); Sun, Pei-Gang (1); Zhang, Xi-Yuan (1) 2007, 28 (11):  1552-1555.  DOI: - Abstract ( 269 )   HTML   PDF (194KB) ( 555 )   According to the need for the wireless sensor network applications in ubiquitous computing environment, a lightweight wireless sensor network OS kernel named uKernel was designed. The improvement of its key techniques especially the task state machine in conventional design procedures was discussed. Based on the conventional embedded RTOS design and energy-saving requirement, the conventional task state machine was improved by way of state decomposition to enable the uKernel to have an energy management mechanism and become a high-efficiency wireless sensor network OS kernel by combining it with corresponding energy-saving algorithm. An experiment was designed to test and verify the effectiveness of energy saving acquired by uKernel. References | Related Articles | Metrics

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A QoS-based integrated strategy of packet scheduling in wireless network Zhao, Yue (1); Li, Jie (1); Zhang, Wei (1); Wang, Guang-Xing (1) 2007, 28 (11):  1556-1559.  DOI: - Abstract ( 269 )   HTML   PDF (323KB) ( 498 )   An integrated strategy of packet scheduling is proposed which is suitable to wireless networks. The strategy combines the WF2Q (worst-case fair weighted fair queueing) algorithm for wired network with the C-IFQ (channel-condition independent packet fair queuing) algorithm for wireless network together to do packet scheduling with different type of sessions sorted out. The result of simulation indicates that it can guarantee packet delay, efficient utilization of bandwidth and long/short-time fairness when scheduling. References | Related Articles | Metrics

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Optimal coverage algorithm of sensor nodes set selection in wireless sensor network Jia, Jie (1); Chen, Jian (1); Chang, Gui-Ran (2); Zhao, Lin-Liang (1) 2007, 28 (11):  1560-1563.  DOI: - Abstract ( 375 )   HTML   PDF (444KB) ( 1112 )   With respect to the high-density deployment of wireless sensor networks, a NP-complete problem is to be solved, i.e., how to find out the minimal number of nodes with the target region fully covered simultaneously. A new optimal algorithm for selecting the set of nodes is thus designed on the basis of genetic algorithm. With the full network coverage provided and part of redundant nodes entering into dormancy, an optimal coverage set of nodes is formed. A simulation test was done to evaluate the performance of the algorithm for network coverage, and the result showed that it can achieve an optimal selection of the set of nodes in hundreds at low cost, thus prolonging efficiently the network lifetime. References | Related Articles | Metrics

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Deformation textures of asymmetrically cold rolled non-oriented silicon steel sheet Zhang, Fang (1); Zhou, Shi-Chun (1); Sha, Yu-Hui (1); Zuo, Liang (1) 2007, 28 (11):  1564-1566+1582.  DOI: - Abstract ( 306 )   HTML   PDF (481KB) ( 930 )   The cold rolling texture distribution along thickness of asymmetrically rolled non-grain oriented (NGO) silicon steel sheet is studied. It is revealed that the cold rolling texture is composed of strong incomplete α(<110>//RD) fiber and relatively weak complete γ fiber (<111>//ND) no matter what rolling schedule is taken on, but asymmetric rolling affects greatly the textural strength and its distribution along thickness. Asymmetric rolling has a greater effect on textural strength of surface and middle layers than on the quarter layer, and it reduces both α and γ fibers with decreasing {111}<110> component, but the {111}<112> component increases somewhat. Thus, the application of asymmetric rolling to cold rolling process can provide a new approach to control and optimize the texture of high-grade NGO silicon steel sheet. References | Related Articles | Metrics

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Texture evolution of 3% non-oriented silicon steel during cross-shear rolling Zhang, Zheng-Gui (1); Qu, Jia-Hui (1); Liu, Yan-Dong (1); Wang, Fu (1) 2007, 28 (11):  1567-1570.  DOI: - Abstract ( 334 )   HTML   PDF (452KB) ( 712 )   The asynchronously cold-rolling texture and formation of recrystallization texture and its evolution were investigated for the 3% non-oriented silicon steel sheet after normalization, to which the rolling speed ratio was 1.06 and thickness was 0.5 mm as cold-rolled just once with 77.3% reduction. The recrystallization annealing of the sheet was done under atmosphere protection. The original texture components of the normalized sheet is mainly the {110} and {113}, while the asynchronously cold-rolling texture is mainly the α and γ. There is no texture type change beside the fast and slow rolls, but the orientation density of α and γ textures is much higher on the side of slow roll than on the side of fast roll. After recrystallization annealing, the orientation density of α texture decreases significantly, while for γ texture the orientation density of {111}<110> texture decreases but that of {111}<112> texture increases. References | Related Articles | Metrics

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Microstructure and properties of C-SiC-B4C composites prepared by hot pressing sintering (I) Yu, Liang (1); Ru, Hong-Qiang (1); Cai, Ji-Dong (1); Zuo, Liang (1) 2007, 28 (11):  1571-1574.  DOI: - Abstract ( 324 )   HTML   PDF (816KB) ( 833 )   C-SiC-B4C composites were prepared with such raw materials as flake graphite Cfg, SiC, B4C and TiO2 by a sintering process, i.e., under 25 MPa hot-pressing at 1750-1900°C × 30 min. The result showed that the bulk density, flexural strength and fracture toughness of all the composites increase obviously with increasing sintering temperature. With the pressure and temperature kept unchanged, the flexural strength decreases and fracture toughness increases with the increasing flake graphite content. And the composite has the best comprehensive mechanical properties where the flexural strength is 142.5 MPa and fracture toughness 4.8 MPa·m1/2 when the mass fractions are Cfg20%, SiC 61.7%, B4C 12.3% and Tift 6% at 1900°C × 30 min. The primary crystalling phase of the composite is lamellar flake graphite of which the interlayer particles are of SiC and B4C and the TiB2 formed in situ. It was found that the toughening mechanism of the composites is mainly that the thermal stress due to the heat expansion mismatching between Cfg and ceramic phase, which results in the toughening effect induced by the lamination of weak crystal boundary. References | Related Articles | Metrics

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Ultra-refinement of austenitic grains in low-carbon structural steel Du, Lin-Xiu (1); Yao, Sheng-Jie (1); Xiong, Ming-Xian (1); Wang, Guo-Dong (1) 2007, 28 (11):  1575-1578.  DOI: - Abstract ( 344 )   HTML   PDF (1063KB) ( 1144 )   Two low-carbon alloyed structural steel of different compositions were investigated via hot-rolling tests and thermal simulation tests for the effects of their chemical compositions, original microstructures and partial heating process on the ultra-fine austenitic grains. The results indicated that the process of warm rolling and cold deformation is most beneficial to enabling the ferritic/pearlitic structure being hot-rolled as original one to obtain ultra-fine austenite with grain size about 1μm. Moreover, adding properly the alloying elements Nb, V and Ti and increasing heating rate can also be helpful to austenitic grain refining, and the ultra-refining effect is not obvious if the heating rate is more than 100°C/s. But, the austenitic grain refining is obvious with homogeneous grain size if the steel is predeformed before heating. References | Related Articles | Metrics

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Causes and control of head warping during plate rolling Tian, Yong (1); Wang, Guo-Dong (1); Zhao, Zhong (1); Wang, Zhao-Dong (1) 2007, 28 (11):  1579-1582.  DOI: - Abstract ( 505 )   HTML   PDF (329KB) ( 1588 )   Head warping is very common during plate rolling. Analyzing the plate rolling process, the problem of how the temperature difference between the top and bottom surface of a plate workpiece and the diameter ratio of upper roll to lower roll after the head warping of workpiece is investigated. A model is developed revealing the relationship between the curvature of head warping, the diameter ratio of upper roll to lower roll and temperature difference between top and bottom surfaces of workpiece. According to rolling parameters, the model can be used to predict the warping curvature, thus providing theoretically reference for proper roll matching. In addition, a measuring method is proposed for head warping curvature by CCD camera. References | Related Articles | Metrics

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Application of data mining based on rough sets and association rule in laminar cooling system Ding, Jing-Guo (1); Hu, Xian-Lei (1); Jiao, Jing-Min (1); Liu, Xiang-Hua (1) 2007, 28 (11):  1583-1585+1598.  DOI: - Abstract ( 255 )   HTML   PDF (158KB) ( 592 )   The process control of coiling temperature can be described mainly by mathematics, but laminar cooling is such a complex non-linear process that it can't be accurately described by mathematics especially at low temperature. According to the measured data of laminar cooling process during plate hot rolling in PanSteel, a decision table is given with sampled, in which the rough set theory is introduced to fuzz up linguistically the sample data so as to mine the implicit association rule by reducing attributes and rejecting redundant rules in accordance to the actual support/confidence level of association rule for linguistic data. Then, the conventional mathematic model for laminar cooling can be optimized by developing a fuzzily dynamic model. The actual operation with measured data shows that this method can improve the controlling precision of coiling temperature by 1%-2% and it has a great application potential. References | Related Articles | Metrics

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Continuous rheo-extrusion of AZ61 magnesium alloy Guan, Ren-Guo (1); Wang, Chao (1); Xing, Zhen-Huan (1); Chen, Li-Qing (2) 2007, 28 (11):  1586-1589.  DOI: - Abstract ( 302 )   HTML   PDF (747KB) ( 993 )   A continuous rheo-extruding process was developed to prepare successfully the AZ61 alloy wire with diameter up to φ10 mm. Under the actions of kneading and shearing by roller and fixed shoe, the fine, spherical and equiaxed grains form from liquid alloy. In the extruding forming process, the deformation of solid phase in the central part is small, while the edgewise deformation is big, then the ultra-fine grain microstructure comes in the arc flowing part. Casting temperature can affect solid fraction and further exert a great influence on the forming process, and the appropriate casting temperature is 680°C. The cross-sectional microstructures of the AZ61 alloy wire prepared is favorable and shows the characteristic of two-phase plastic flow. References | Related Articles | Metrics

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Experimental investigation on dealkalization and desulphurization of alkaliferous BF slag Lu, Qing (1); Li, Fu-Min (1); Gu, Lin-Na (3); Hou, Da-Hua (3) 2007, 28 (11):  1590-1593.  DOI: - Abstract ( 542 )   HTML   PDF (372KB) ( 1037 )   Investigates experimentally the relationship between dealkalization and desulphurization of alkaliferous BF slag. The influences of w (CaO)/w (SiO2), w (MgO) and w (Al2O3) on the two removabilities are studied according to the actual BF slag composition of GuangSteel. The results reveal that w (CaO)/w (SiO2) has great influence on both the two removabilities and they contradict each other. The dealkalizing rate falls with rising w (MgO), and the w (MgO) corresponding to best desulphurizing rate on alkaliferour slag is 3% lower than on normal slag. The change of dealkalizing rate is little but the desulphurizing rate decreases rapidly with rising w (Al2O3). For the sample slag appropriate composition is that the w (CaO)/w (SiO2) shall be kept 1.0, with w (MgO) 12% and w (Al2O3) 15%. References | Related Articles | Metrics

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Entropy analysis of copper cycle for China Yue, Qiang (1); Lu, Zhong-Wu (1) 2007, 28 (11):  1594-1598.  DOI: - Abstract ( 223 )   HTML   PDF (448KB) ( 784 )   To ascertain the levels of aggregation and dissipation of cupric materials in copper cycle, the index of entropy in thermodynamics is introduced into material flow analysis to give the distribution and calculating method of entropy. The variation of entropy in the whole copper cycle is calculated involving 4 phases, i.e., copper refining, products processing/manufacturing, utilization of products and recycling of abandoned products, based on the analysis of copper cycle in China in 2002. The values of relative entropy at the five respective nodes in the copper cycle are 0.32149, 0.06337, 0.23946, 0.59919 and 0.50786. The rate of change of relative entropy in the whole process is 57.97% which means that the cupric materials tend to serious dissipation. Some measures are suggested to take to decrease the loss rates of different links in the whole copper cycle, including are mining, dressing, smelting and tailing/slag disposed, so as to improve the recycling rate of abandoned copper products and lower effectively the increment of entropy in copper cycle. References | Related Articles | Metrics

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Study on particle flow in shaft moving beds Cai, Jiu-Ju (1); Dong, Hui (1); Fu, Wei (1) 2007, 28 (11):  1599-1603.  DOI: - Abstract ( 191 )   HTML   PDF (734KB) ( 676 )   In a shaft moving bed, the heat and mass are generally transferred between particles and gases, besides the chemical reactions in it. It's of great significance to study the particle flow in the moving bed for intensifying heat exchange and chemical reactions. Making reference to PSF (pelletizing shaft furnace), the rule of particle flow in the shaft moving bed was investigated combining experiments with simulation. The results showed that the kinematic model and viscous flow model are principal ones to simulate the particles flow, among which the viscous flow model is more applicable to PSF. And the appropriate value of the coefficient in the kinematic model may be fetched to be 0.02 m with the value of the viscous factor fetched 0.15 Pa·s. The simulation introducing the viscous flow model revealed that the pellets are flowing uniformly and approach to plug flow in PSF. The result also revealed that the inclination angle of tilting wall of PSF plays an important role in the parallel flow of particles in PSF. References | Related Articles | Metrics

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On the relation between cooling rate and activity of boron-rich slag Zhan, Hong-Ren (1); Liu, Su-Lan (1); Fan, Zhan-Guo (1) 2007, 28 (11):  1604-1607.  DOI: - Abstract ( 211 )   HTML   PDF (982KB) ( 541 )   The slow cooling process of boron-rich slag which was separated from paigeite with iron in a small 13 m3 blast furnace was studied through testing. The activity or leaching ratio of boron can be increased to 83.72% from 40.05% by changing the cooling conditions for the boron-rich slag melt, i.e. in the temperature range from 1500°C to 1200°C the cooling rate is controlled form 0.76°C/min to 20°C/min and in the range from 1200°C to 900°C the rate is lower than 2°C/min. The higher the cooling rate, the higher the activity or leaching ratio of the boron-rich slag. The testing results are coincided with theoretical investigation and the results of bench scale test, which showed that the leaching ratio can be improved actually through two-stage cooling schedule and the way to design the cooling system in future. References | Related Articles | Metrics

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Generalized evaluation based on AHP/grey theory for product quality Liu, Jie (1); Li, Chao-Feng (1); Sun, Wei (1); Wen, Bang-Chun (1) 2007, 28 (11):  1608-1611.  DOI: - Abstract ( 235 )   HTML   PDF (325KB) ( 612 )   To improve product quality, the product quality is analyzed in depth in a broad sense involving its connotation and denotation. An idea of generalized product quality is thus presented with a relevant evaluation index system suggested including all functions and comprehensively clustered performance of a product in view of its construction, operation and process technology. In this way the complexity and relational hierarchy of the generalized product quality in evaluation are fully considered by introducing AHP in combination with grey theory to make the fuzziness, complexity and difficulty in quantification compatible with each other. Then, taking a domestic excavator as example, its generalized product quality is evaluated comprehensively, and the results show that the generalized evaluation system for product quality can provide a scientific basis for decision making on product design/manufacture, quality evaluation and orientation of enterprise. References | Related Articles | Metrics

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A novel method for estimating frequency and amplitude in spectrum correction Li, Yun-Gong (1); Liu, Jie (1); Wang, Rui (1); Zhao, Bo (1) 2007, 28 (11):  1612-1615.  DOI: - Abstract ( 177 )   HTML   PDF (168KB) ( 817 )   It is unavoidable that considerable errors will be found in the results of the discrete Fourier transform (DFT), of which the root cause is that the initial frequency is set to zero in DFT calculation. A novel method named initial frequency scan (IFS) is therefore proposed to estimate the frequency and amplitude for spectrum correction, including both the single and whole frequency band estimation. The basic principle of IFS is to scan different frequencies in a frequency resolution as optimization interval to estimate the frequency and amplitude with the max amplitude as criterion. Then, an optimal frequency/amplitude estimation is implemented via the initial frequency point that is found by regulating DFT calculation. The results show the high accuracy of IFS, i.e., the error magnitude can be kept at 10-3, without strict requirement of signal units. In addition, the noise intensity affects unobviously the estimation accuracy. All these verify that the method proposed is highly practical. References | Related Articles | Metrics

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Flexural vibration analysis of symmetric honeycomb panel with 4 sides simply supported Huang, Xu-Qiang (1); Lu, Chao-Yang (1); Cai, Ming-Hui (2); Li, Yong-Qiang (3) 2007, 28 (11):  1616-1619.  DOI: - Abstract ( 329 )   HTML   PDF (311KB) ( 649 )   The free flexural vibration of symmetric honeycomb sandwich panel with 4 sides simply supported is analyzed by CPT (classical plate theory), FSDPT (first-order shear deformation plate theory) and TSDPT (third-order shear deformation plate theory). In the analysis the honeycomb core of cells is regarded equivalently as a layer of orthotropic material whose equivalent elastic parameters are determined by the modified Gibson's formula to deduce the equation of natural frequency of the sandwich panel. As shown by an example, the calculation of natural frequency of an aluminum honeycomb panel by use of TSDPT is higher accuracy than using either CPT or FSDPT. References | Related Articles | Metrics

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Time-dependent reliability model and failure rate study of mechanical components Wang, Zheng (1); Xie, Li-Yang (1); Li, Bing (1) 2007, 28 (11):  1620-1623.  DOI: - Abstract ( 306 )   HTML   PDF (1452KB) ( 1035 )   The characteristics of the conventional reliability models are analyzed and it is found that they can't reflect well the relationship between the reliability and failure rate of components because it involves not only the time but also the frequency of random loading. The Poisson stochastic process is applied to describing the loading process to develop a time-dependent reliability model of components considering the strength deterioration with time passing, which is derived by the stress-strength interference model in combination with the probability differential equation. Taking the strength deterioration of components following the exponential rule as an example, how the reliability and the failure rate of components changes with time is studied. The result shows that the reliability of components decreases with time, and the failure rate curve of components presents all the features of the bathtub curve. References | Related Articles | Metrics

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Construction method of surface quality evaluation model for cold-rolled strip steel Wu, Yan-Ping (1); Yan, Yun-Hui (1); Wang, Yong-Hui (1); Li, Jun (1) 2007, 28 (11):  1624-1627.  DOI: - Abstract ( 337 )   HTML   PDF (939KB) ( 608 )   The surface quality evaluation of cold rolled strip steel is a complex problem involving many influencing factors among which many different causes of formation of surface defects are possible and the amount, level, position and distribution of surface defects affect differently the surface quality. Abstracting the surface quality from those factors and regarding it as a multifactor, multi-hierarchy and multi-scheme system by means of AHP (analytic hierarchy process), the quality evaluation problem can be transformed into an analysis program and decision making problem. A relatively perfect surface quality evaluation index system is thus provided by determining the weights of all influencing factors on surface quality at different levels. This system is available to ensure the scientific and precise evaluation, and an application example is given to verify its practicality and validity. References | Related Articles | Metrics

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Dynamic performances analysis of NC machine tool considering linear rolling guideway Zhang, Yao-Man (1); Liu, Chun-Shi (2); Xie, Zhi-Kun (1); Liu, Yong-Xian (1) 2007, 28 (11):  1628-1631.  DOI: - Abstract ( 329 )   HTML   PDF (399KB) ( 962 )   To design a machine tool successfully, its essential parts should be analyzed and evaluated after design but before prototype being made. The linear rolling guideway is one of the usual parts of NC machine tool, so the dynamic/static characteristics of NC machine tools equipped with rolling guideway and how the guideway affects the performance of NC machine tools are of great significance and should be studied. With the CKS6125 NC machine tool manufactured by a certain plant as instance, a FEA (finite element method) is proposed to simulate the dynamic characteristics of the joint parts of rolling guide and study the configuration of spring/damping elements for guide supports. A FEA model for the feed unit of the machine tool is thus developed to analyze and confirm its dynamic characteristics. The FEA model has been verified through experiments. References | Related Articles | Metrics

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Self-correlation and PSD analysis of surface lapping with abrasive jet flow restricted by grinding wheel Liu, Feng (1); Gong, Ya-Dong (1); Cai, Guang-Qi (1); Huang, Ya-Li (1) 2007, 28 (11):  1632-1635.  DOI: - Abstract ( 306 )   HTML   PDF (1017KB) ( 651 )   The aim of abrasive jet flow finishing process as a new lapping technology is to remove further the surface defect layer and diminish roughness and ripple. Experiments were performed on a plane grinder M7120 with a #45 steel workpiece as specimen of which the surface roughness values of Ra = 0.2-0.6μm. The micromorphology of machined surface was observed using SEM with the microcosmic geometry parameters measured by TR200 profilometer. With the correlation in stochastic process applied to the experimental results, the surface during grinding and further lapping with liquid abrasive jet flow restricted by grinding wheel was investigated with respect to self-correlation and PSD (power spectra density) analysis. The results indicated that such a new finishing process can diminish and equilibrate roughness and ripple of ground surface to improve greatly the surface quality. References | Related Articles | Metrics

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On the automatic negotiation scheme combining GA with agent Wang, Gui-He (1); Jiang, Xing-Yu (1); Fan, Li-Min (2); Wang, Wan-Shan (1) 2007, 28 (11):  1636-1639.  DOI: - Abstract ( 267 )   HTML   PDF (321KB) ( 676 )   To solve the problem of automatic negotiation, the characteristics and operating principle of an agent and the proceeds through negotiation were analyzed. A model based on agent was developed with the process of negotiation described including relevant parameters and goal. A strategy based on genetic algorithm was presented and its coding method and parameter setting and the solution process were studied with an optimum solution given to the model. The results showed that this strategy can optimize continuously the model and enable both agents who negotiated with each other to realize a win-win situation, thus verifying the validity of the scheme of automatic negotiation. References | Related Articles | Metrics

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Automotive hierarchical control network based on TTCAN and CAN for entire cars and its scheduling strategy Cao, Wan-Ke (1); Zhang, Tian-Xia (1); Zhou, Shu-Wen (1); Chen, Qi-Ming (1) 2007, 28 (11):  1640-1643.  DOI: - Abstract ( 278 )   HTML   PDF (479KB) ( 820 )   To meet different requirements of automotive power transmission system and bodywork control system, a hierarchical control network was constructed for entire cars and its scheduling strategy was studied. Analyzing the characteristics of information in automotive control system, a new network was designed interconnecting TTCAN (time triggered controller area network) for power transmission system with CAN (controller area network) for bodywork control system. The AL (average loading) algorithm is proposed to schedule TTCAN and RM (rate monotonic) algorithm introduced to schedule CAN. Finally the scheme proposed is applied to automotive control system, and the result of real-time analysis verifies the feasibility of the scheme. References | Related Articles | Metrics

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Analysis of primary/middle school students' ecological footprint in Shenyang Wang, Jun (1); Wang, Qing (1); Zhang, Su-Wu (2); Li, Guang-Jun (1) 2007, 28 (11):  1644-1647.  DOI: - Abstract ( 419 )   HTML   PDF (203KB) ( 693 )   The componential method of the ecological footprint was introduced to the case studies of primary/middle school students in Shenyang, the results show that: (1) The biggest component of primary/middle school students' ecological footprint is meat with electric power next to it, and both account for 75% of the total personal ecological footprint; (2) The personal ecological footprint doesn't relate obviously to the age but closely relates to the personal preference and consumption level; (3) The average ecological footprint of boys are greater than girls. The results will make these students aware quantitatively of how much the ecology and environment protection mean to them if knowing the effect of consumption on ambience. References | Related Articles | Metrics

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Numerical simulation of wind velocity history on the basis of orthogonal inverse wavelet transform Bai, Quan (1); Zhu, Fu-Sheng (1); Bian, Jing-Mei (1); Dong, Feng (3) 2007, 28 (11):  1648-1651.  DOI: - Abstract ( 257 )   HTML   PDF (1188KB) ( 596 )   Wind load is one of the major even decisive factors to large-structure for which the time domain analysis of wind-induced dynamic response is required. The problem how to input the wind load is therefore to be solved first. According to the idea of multi-resolution analysis and orthonormal wavelets, relationship between wavelet coefficients and PSD (power spectral density) function is deduced, then the wavelet coefficients on each and every scale are obtained from the given PSD function. As a result, the inverse wavelet transform is applied to generating stationary wind velocity history through the given wavelet coefficients. In this way the L-P wavelet is applied to simulating the pulsate wind velocity history at a certain point, which conforms to Davenport power spectral density. A numerical example shows that the simulated PSD is consistent with the prescribed one and the method is valid. References | Related Articles | Metrics

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Analysis of tire's dynamic contact pressure during braking by 3-D FEM Zhang, Jun (1); Zhu, Fu-Sheng (1); Wu, Ze-Feng (3) 2007, 28 (11):  1652-1655.  DOI: - Abstract ( 267 )   HTML   PDF (1051KB) ( 1019 )   The tire's dynamic contact pressure and its distribution during braking were analyzed by the 3-D FEM, where the tire was regarded as a solid one with relevant parameters given by fitting several values on the principle of equivalent deformation. The results indicated that the area on low-pressure tire due to contact pressure is similar to a trapezoid, while that on high-pressure tire is like a rectangle. The contact pressure increases with increasing tire pressure under constant load, and then the contact pressure increases when the tire load is constant. The tire's dynamic contact pressure is greater than its static contact pressure. All these show that the FEM results approximate to the measured results in situ. The method proposed is thus proved feasible to analyze tire's dynamic contact pressure during braking. References | Related Articles | Metrics

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Economic factors analysis based on complete decomposition model for energy consumption in Liaoning Province Li, Kai (1); Li, Ming-Yu (1); Yu, Pei-Li (1); Sun, Guang-Sheng (1) 2007, 28 (11):  1656-1659.  DOI: - Abstract ( 259 )   HTML   PDF (259KB) ( 904 )   Taking the energy intensity into account, the non-residue complete decomposition model is applied to the quantitative analysis of the effects of three economically factors on the change in energy consumption in Liaoning PRC, i.e., the economic growth and pattern and technological progress. Then, the results from the analysis are compared with the average level of the whole country to find out the characteristics of energy consumption in Liaoning Province and how these factors affected the change in energy consumption in different periods. The results will provide a scientific reference for energy policy formulating and improving energy-saving efficiency in the province. References | Related Articles | Metrics

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Co-integration of high-frequency data between the call warrants and their underlying target stocks on Shanghai Stock Market Liu, Yang (1); Chen, Si-Si (2); Zhuang, Xin-Tian (1) 2007, 28 (11):  1660-1664.  DOI: - Abstract ( 224 )   HTML   PDF (205KB) ( 979 )   The Black-Scholes option pricing model is often applied to pricing the warrant, which has some strict hypotheses and therefore the underlying target assets affect greatly the pricing practice. When there is no co-integration relationship between warrants and underlying target stocks, the Black-Scholes option model can not confirm the price of warrants efficiently. EG test and Johansen test are used to analyze the co-integration between the call warrants in Shanghai Stock Market and its underlying target stocks, and the result shows no co-integration between them. Moreover, the price trend of the call warrants will deviate from their underlying stocks, thus limiting the pricing practice to a certain extent when using the Black-Scholes option pricing model. It reveals the serious speculation in our warrant market. References | Related Articles | Metrics

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Influencing factors on financing structure of small/medium-size enterprises in Northeast China's old industrial base Zhong, Tian-Li (1); Jia, Qiu-Ying (1); Jiang, Yong-Min (1) 2007, 28 (11):  1665-1668.  DOI: - Abstract ( 239 )   HTML   PDF (133KB) ( 563 )   Due to the differences in economic development levels and financial system, the theory and practice of financing both vary obviously in different regions. So, an empirical analysis is made of the financing structure and influencing factors on the SMEs (small/medium-size enterprises) in Northeast China's old industrial base through comparing it with other developed regions by means of multi-linear regression model and stepwise regression. The result shows that both the structure and factors mentioned above are different from those in other developed regions, e.g., most of the SMEs are state-owned and traditional manufacturers with low accumulation of funds and high assets-liabilities ratio, the selection of financing for liabilities has been transferred to commercial credit from traditional bank loan or other forms of indebtedness, the total assets and number of employees are significantly related to the financing for liabilities, which shows that the 'scale discrimination' is specially obvious in the Northeast China's old industrial base. References | Related Articles | Metrics

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Study on fusion method of multi-granularity linguistic term sets Liu, Jun (1); Guo, Ya-Jun (1); Tian, Xi-Long (2); Pan, De-Hui (1) 2007, 28 (11):  1669-1672.  DOI: - Abstract ( 382 )   HTML   PDF (213KB) ( 1009 )   The fusion problem of multi-granularity linguistic term sets for assessment in decision making process is studied with two existing fusion methods discussed. A new fusion method based on membership function is proposed to express the linguistic assessment in terms of 2-tuple semantics and the overlapping fuzzy numbers over the interval [0, 1]. Such a method thus avoids the disadvantage of original methods which can only convert the low-granularity sets into high-granularity ones, besides its simple calculation. A numerical example is given to demonstrate that the new fusion method can give the accurate score to an alternative and benefit the solutions to the problems of linguistic term sets with different granularities in group decision-making processes. References | Related Articles | Metrics