Regularization method is an effective method for solving ill\|posed equation. In this paper the unbiased estimation formula of unit weight standard deviation in the regularization solution is derived and the formula i...Regularization method is an effective method for solving ill\|posed equation. In this paper the unbiased estimation formula of unit weight standard deviation in the regularization solution is derived and the formula is verified with numerical case of 1 000 sample data by use of the typical ill\|posed equation, i.e. the Fredholm integration equation of the first kind.展开更多
An efficient calibration algorithm for an ambulatory audiometric test system is proposed. This system utilizes a personal digital assistant (PDA) device to generate the correct sound pressure level (SPL) from an audio...An efficient calibration algorithm for an ambulatory audiometric test system is proposed. This system utilizes a personal digital assistant (PDA) device to generate the correct sound pressure level (SPL) from an audiometric transducer such as an earphone. The calibrated sound intensities for an audio-logical examination can be obtained in terms of the sound pressure levels of pure-tonal sinusoidal signals in eight-banded frequency ranges (250, 500, 1 000, 2 000, 3 000, 4 000, 6 000 and 8 000 Hz), and with mapping of the input sound pressure levels by the weight coefficients that are tuned by the delta learning rule. With this scheme, the sound intensities, which evoke eight-banded sound pressure levels by 5 dB steps from a minimum of 25 dB to a maximum of 80 dB, can be generated without volume displacement. Consequently, these sound intensities can be utilized to accurately determine the hearing threshold of a subject in the ambulatory audiometric testing environment.展开更多
The discrete variational (DV) and DMol methods within the framework of density functional theory are used to study the effect of alloying element Nb on Fe γ phase.The impurity formation energy in bulk and segregation...The discrete variational (DV) and DMol methods within the framework of density functional theory are used to study the effect of alloying element Nb on Fe γ phase.The impurity formation energy in bulk and segregation energies at grain boundary and free surface are calculated.The results show that Nb prefers to segregate at grain boundary.The difference in segregation energies between the grain boundary and the corresponding free surface is -0.39 eV for solute Nb.According to Rice-Wang model,it can be predicted that Nb can enhance grain boundary cohesion.The calculated results of interatomic energy and charge density show that charge would be redistributed,and the bonds across grain boundary are strengthened by the substitution of Nb for Fe.As a result,it is difficult for the grain boundary to move.Thus the dragging effect of Nb is explained electronically.展开更多
文摘Regularization method is an effective method for solving ill\|posed equation. In this paper the unbiased estimation formula of unit weight standard deviation in the regularization solution is derived and the formula is verified with numerical case of 1 000 sample data by use of the typical ill\|posed equation, i.e. the Fredholm integration equation of the first kind.
基金supported by the grant of the Korean Ministry of Education, Science and Technology (The Regional Core Research Program/Chungbuk BIT Research-Oriented University Consortium)
文摘An efficient calibration algorithm for an ambulatory audiometric test system is proposed. This system utilizes a personal digital assistant (PDA) device to generate the correct sound pressure level (SPL) from an audiometric transducer such as an earphone. The calibrated sound intensities for an audio-logical examination can be obtained in terms of the sound pressure levels of pure-tonal sinusoidal signals in eight-banded frequency ranges (250, 500, 1 000, 2 000, 3 000, 4 000, 6 000 and 8 000 Hz), and with mapping of the input sound pressure levels by the weight coefficients that are tuned by the delta learning rule. With this scheme, the sound intensities, which evoke eight-banded sound pressure levels by 5 dB steps from a minimum of 25 dB to a maximum of 80 dB, can be generated without volume displacement. Consequently, these sound intensities can be utilized to accurately determine the hearing threshold of a subject in the ambulatory audiometric testing environment.
基金This work was supported by 973 Project of China (No. G2000067102) the National Natural Science Foundation of China (Grant No. 59971041).
文摘The discrete variational (DV) and DMol methods within the framework of density functional theory are used to study the effect of alloying element Nb on Fe γ phase.The impurity formation energy in bulk and segregation energies at grain boundary and free surface are calculated.The results show that Nb prefers to segregate at grain boundary.The difference in segregation energies between the grain boundary and the corresponding free surface is -0.39 eV for solute Nb.According to Rice-Wang model,it can be predicted that Nb can enhance grain boundary cohesion.The calculated results of interatomic energy and charge density show that charge would be redistributed,and the bonds across grain boundary are strengthened by the substitution of Nb for Fe.As a result,it is difficult for the grain boundary to move.Thus the dragging effect of Nb is explained electronically.
