Ping Y.,Heilongjiang Institute of Science and Technology |
Yongheng L.,Heilongjiang Institute of Science and Technology
Expert Systems with Applications | Year: 2011
The credit scoring model development has become a very important issue, as the credit industry is highly competitive. Therefore, considerable credit scoring models have been widely studied in the areas of statistics to improve the accuracy of credit scoring during the past few years. This study constructs a hybrid SVM-based credit scoring models to evaluate the applicant's credit score according to the applicant's input features: (1) using neighborhood rough set to select input features; (2) using grid search to optimize RBF kernel parameters; (3) using the hybrid optimal input features and model parameters to solve the credit scoring problem with 10-fold cross validation; (4) comparing the accuracy of the proposed method with other methods. Experiment results demonstrate that the neighborhood rough set and SVM based hybrid classifier has the best credit scoring capability compared with other hybrid classifiers. It also outperforms linear discriminant analysis, logistic regression and neural networks. © 2011 Elsevier Ltd. All rights reserved.
Wang P.,Heilongjiang Institute of Science and Technology
Applied Mechanics and Materials | Year: 2010
The grey relational analysis method of the grey systems theory are combined with the fault tree analysis method of reliability theory, and introduced to the analysis and diagnosis of mine hoist overrelaxation accident. The various fault pattern occurrence possibilities in fault tree analysis of mine hoist overrelaxation accident are analyzed and judged by calculating importance degree of the bottom event structure of the fault tree as well as the calculating and sorting of the grey relational degree.Among 8 minimum cut sets of 6 bottom events ,"lake of the overrelaxation switch of the parking place" is most prone to overrelaxation accident ,"the driver's negligence" is also prone to overrelaxation accident ,which provides theoretical basis for accurately preventing the fault occurrence. Calculation example shows the effectiveness and reliability of this method. © (2010) Trans Tech Publications.
Yanqin Z.,Heilongjiang Institute of Science and Technology
International Journal of Mining Science and Technology | Year: 2013
Based on low illumination and a large number of mixed noises contained in coal mine, denoising with one method usually cannot achieve good results, so a multi-level image denoising method based on wavelet correlation relevant inter-scale is presented. Firstly, we used directional median filter to effectively reduce impulse noise in the spatial domain, which is the main cause of noise in mine. Secondly, we used a Wiener filtration method to mainly reduce the Gaussian noise, and then finally used a multi-wavelet transform to minimize the remaining noise of low-light images in the transform domain. This multi-level image noise reduction method combines spatial and transform domain denoising to enhance benefits, and effectively reduce impulse noise and Gaussian noise in a coal mine, while retaining good detailed image characteristics of the underground for improving quality of images with mixing noise and effective low-light environment. © 2013 Published by Elsevier B.V. on behalf of China University of Mining & Technology.
Wu W.L.,Heilongjiang Institute of Science and Technology
Materials Science and Technology | Year: 2010
TiC reinforced Ti matrix composite layer was fabricated by laser cladding of Ti and TiC powder mixture on Ti-6Al-4V alloy. Dissolution precipitation mechanism was speculated to illustrate the formation of TiC dendrite in the composite layer. Microstructure evolution of the composite layer has been explained by this mechanism. The composite incorporates the advantages of external particle composites and in situ synthesised particle composites. This mechanism offers an alternative novel idea for the design of bulk composites as well as composite layers. The composite layer exhibits high hardness and excellent wear resistance. © 2010 Institute of Materials, Minerals and Mining.
Yu F.,Heilongjiang Institute of Science and Technology
Advanced Materials Research | Year: 2011
Tensile tests were carried out on demagnetization 16Mn and Q235 steel samples at loading state, and the magnetic memory characteristics were analyzed. Experimental results show the mean magnetic field intensity (MMFI) of a measuring point is more effective than that of other measuring points at the same stage to study tensile magnetic memory characteristics of demagnetization 16Mn and Q235 steel samples. At the elastic deformation stage, the MMFI of the measuring points at one fracture side increases while it decreases on the other fracture side. The MMFI decreases with the distance from the fracture location, and the change rate of the MMFI is almost equal. The variation law shows changes of opposite direction. At the strengthening phase, the relation between MMFI and tensile displacement is similar with that of the plastic deformation stage, but the variation amplitude was accelerated obviously. Comparison of 16Mn and Q235 steel shows that the standard deviation variation of the magnetic field intensity with the tensile displacement increases as the tensile strength of materials increases. For the demagnetization bearing components, weak areas can be estimated according to breaking laws, so more monitoring points can be set. Pre-breaks could be found through the appearance of inflection point of the MMFI of monitoring point. The inflection point of the mean curve is the breakpoint. © (2011) Trans Tech Publications.
Wang X.-D.,Heilongjiang Institute of Science and Technology
Meitan Xuebao/Journal of the China Coal Society | Year: 2010
Aimed at attenuating the harmonics caused by high power DC drive system, proposed a new PWM topology of converters, that is, work styles of the hybrid energy storage in DC side and series resonant to form the new type of parallel active filters with reactive and active. Introduced the PWM control strategy of the new active filter with reactive and active and a harmonic control strategy based on the Fourier transform to compensate for harmonic of the 5th, 7th, 11th, 13th in three-phase power system. The proposed control strategy was accomplished through TMS320F240 DSP. In the laboratory, experimental prototypes were constructed to carry out experimental study. The present study finds that the harmonic of the 5th, 7th, 11th, 13th in the system is subjected to better suppression, so that the THD of net-side currents decreases from 26.4% to 12.8%, with a significant reduction in total harmonic distortion rate, which verifies the effectiveness of the control strategy and its implementation.
Hu C.,Heilongjiang Institute of Science and Technology
Communications in Computer and Information Science | Year: 2011
After the PC and the Internet technology, Web Service technology is touted as the third IT technology revolution. Although the application range of Web Service is expanding in the areas of e-business and e-government. But the adoption of Web Service standard is still very slow. This paper introduces the Web Service technology standard system, based on the innovation diffusion analysis framework of Technology - Organization - Environment (TOE) analyses the main factors affecting the adoption and diffusion of Web Service technology standards. © 2011 Springer-Verlag.
Yu C.,Heilongjiang Institute of Science and Technology
Advanced Materials Research | Year: 2012
The Power Enterprise asset valuation is usually the market price at market in the current market price down algorithm or method, as im of China's timber market, trading behavior is not very standardized, resulting in the use of market price of Evaluating the value out of Power Enterprise asset valuation, can not be objective and realistic response to the full value of Power Enterprise assets. This article will introduce AHP Power Enterprise asset valuation, the price of power species, Power Enterprise by constructing the AHP model, constructed response relationship between the various levels of indicators to determine the weight matrix to determine the lowest level of index membership, the calculation method to determine the individual materials species, the average price of a Power Enterprise assets, significantly improving the effectiveness and reliability of assessment. © (2012) Trans Tech Publications.
Zhang B.,Heilongjiang Institute of Science and Technology |
Wu Q.,Heilongjiang Institute of Science and Technology
Energy and Fuels | Year: 2010
This paper proposed a new hydrate-based gas separation (HBGS) method especially for recovering methane from low-concentration coal mine methane (CMM). The main purpose of this study was to evaluate the thermodynamic promotion of tetrahydrofuran (THF) on methane recovery from low-concentration CMM. Temperature and pressure conditions for incipient hydrate formation (vapor-aqueous liquid-hydrate) were closely examined at various different THF concentrations (1.00, 0.10, and 0.01 mol L-1) in gas hydrate systems (CH4-N2-O2-THF-H2O) and at various initial operating pressures (8, 10, and 14 MPa). Subsequently, the phase equilibrium parameters of hydrate formation for the CH4-N 2-O2-H2O system were calculated using the Chen-Guo model and the Patel-Teja equation of state. The difference between experimental and calculated values indicates that the addition of THF significantly reduced the equilibrium formation conditions. The higher the THF concentration and the initial operation pressure, the more significant the promotion effect of THF. THF with a concentration of 1 mol L-1 was found to promote CH4 capture the best under an initial operation pressure of 14 MPa in the range of those examined. The present study illustrates the concept and provides thermodynamic data that will aid in the design and production of an effective hydrate-based methane recovery process. © 2010 American Chemical Society.
Chen T.,Harbin University of Science and Technology |
Li S.,Heilongjiang Institute of Science and Technology |
Sun H.,Harbin University of Science and Technology
Sensors | Year: 2012
Metamaterials are artificial media structured on a size scale smaller than wavelength of external stimuli, and they can exhibit a strong localization and enhancement of fields, which may provide novel tools to significantly enhance the sensitivity and resolution of sensors, and open new degrees of freedom in sensing design aspect. This paper mainly presents the recent progress concerning metamaterials-based sensing, and detailedly reviews the principle, detecting process and sensitivity of three distinct types of sensors based on metamaterials, as well as their challenges and prospects. Moreover, the design guidelines for each sensor and its performance are compared and summarized. © 2012 by the authors.