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71.
Subspace information criterion for model selection 总被引:7,自引:0,他引:7
The problem of model selection is considerably important for acquiring higher levels of generalization capability in supervised learning. In this article, we propose a new criterion for model selection, the subspace information criterion (SIC), which is a generalization of Mallows's C(L). It is assumed that the learning target function belongs to a specified functional Hilbert space and the generalization error is defined as the Hilbert space squared norm of the difference between the learning result function and target function. SIC gives an unbiased estimate of the generalization error so defined. SIC assumes the availability of an unbiased estimate of the target function and the noise covariance matrix, which are generally unknown. A practical calculation method of SIC for least-mean-squares learning is provided under the assumption that the dimension of the Hilbert space is less than the number of training examples. Finally, computer simulations in two examples show that SIC works well even when the number of training examples is small. 相似文献
72.
Mitsuhiro Horade Sommawan Khumpuang Kazuya Fujioka Susumu Sugiyama 《Microsystem Technologies》2007,13(3-4):215-219
We have investigated and report in this paper the factors influencing the deformation caused by the dependence between the
absorbed X-ray energy on the resist and the shape of the absorber on the X-ray mask. Based on the measurement of errors that
occurred during the transferring process between the 2-D shape of mask pattern and the resulting wall of the fabricated 3-D
structure, we have developed newly useful graphical data on the absorbed X-ray energy, dosage, and shape of a microstructure.
As a result, it is being reported as a method for compensation for the deformed shape after the fabrication of a quadruplets-microneedle.
We have considered a number of factors affecting the deformation and finally realized that the effect of a dose–depth nonlinear
curve is the most possible cause. Without the compensation of the mask design, we could observe the deformed shapes of the
sloped sidewall on the exposed structures. Polymethylmethacrylate microneedle structures fabricated by X-ray lithography with
an additional plane-pattern to cross-section transfers technique are directly influenced by the absorber on the X-ray mask
pattern. The sidewall of the microneedle was improved by changing the mask pattern from a double right-triangular pattern
to a double semi-circular pattern, modeled by comparing the results from a mask-pattern and the actual structure. 相似文献
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75.
A system procedure is proposed for a multi-robot rescue system that performs real-time exploration over disaster areas. Real-time exploration means that every robot exploring the area always has a communication path to human operators standing by at a base station and that the communication path is configured by ad hoc wireless networking. Real-time exploration is essential in multi-robot systems for USAR (urban search and rescue) because operators must communicate with every robot to support the victim detection process and ad hoc networking is suitable to configure a communication path among obstacles. The proposed system procedure consists of the autonomous classification of robots into search and relay types and behavior algorithms for each class of robot. Search robots explore the areas and relay robots act as relay terminals between search robots and the base station. The rule of the classification and the behavior algorithm refer to the forwarding table of each robot constructed for ad hoc networking. The table construction is based on DSDV (destination-sequenced distance vector) routing that informs each robot of its topological position in the network and other essentials. Computer simulations are executed with a specific exploration strategy of search robots. The results show that a multi-robot rescue system can perform real-time exploration with the proposed system procedure and reduce exploration time in comparison with the case where the proposed scheme is not adopted. 相似文献
76.
This paper describes the fabrication of poly(methyl methacrylate) (PMMA) microstructures with three-dimensional (3-D) sloped sidewalls using synchrotron-radiated (SR) deep X-ray lithography (DXRL). Here, the developer temperature was varied to produce variations in the inclination angle of the sloped sidewalls. We found that the PMMA sidewall inclination angle and height were controlled by the dosage, development time, and development temperature. When the development temperature was low, the inclination angle was nearly 0°, regardless of dosage amounts or exposure time. When the development temperature was high, microstructures with sloped sidewalls were fabricated; as the dosage amount and development time increased, the inclination angle increased. The ability to control the PMMA sidewall inclination angle suggests the application of this technique to microstructure fabrication technologies, such as 3-D microelectromechanical system (MEMS) device components, in which the inclination angle becomes the draft angle for moulding processes. 相似文献
77.
A large discrepancy between defect densities evaluated by constant photocurrent method (CPM) and electron spin resonance (ESR) is investigated for hydrogenated amorphous silicon (a-Si:H) with various thicknesses in the process of light soaking (LS). It is shown by a computer simulation that the inhomogeneous defect distribution across the film thickness caused by a rather small penetration depth of the white light in the thick film is one of the possible origins of the discrepancy. But various other causes should also bring about the discrepancy, and the problem is still a puzzling one. 相似文献
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79.
Tomoya Nagira Shugo Morita Hiroyoshi Yokota Hideyuki Yasuda Christopher M. Gourlay Masato Yoshiya Akira Sugiyama Kentaro Uesugi Akihisa Takeuchi Yoshio Suzuki 《Metallurgical and Materials Transactions A》2014,45(12):5613-5623
Synchrotron X-ray radiography at 125 frames per second was used to study deformation mechanisms in semi-solid Fe-C alloys at high solid fraction and shear strain rates of 10?1/s. An image correlation approach was also used to quantify the shear strain fields and study shear-induced dilation and the origin of shear cracking. It was shown that, at high solid fraction (90 to 93 pct solid), rearrangement including rotation and translation of solid particles became restricted and shear strain localized into narrow liquid-filled channels/fissures. Shear cracking was shown to originate from inadequate liquid flow into the expanding spaces between solid particles caused by shear-induced dilation. At lower solid fraction (~85 pct solid), solid particles rearranged with a significantly higher component of rotation leading to more shear-induced dilation and a wider shear band. 相似文献
80.