Browsing by Author "Huang, KL"

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Cascade-CMAC neural network applications on the color scanner to printer calibration
(1997)
Huang, KL
;
Hsieh, SC
;
Fu, HC
;
交大名義發表
;
光電工程學系
This paper presents an application of using a Cascade-CMAC (Cerebellar Model Articulation Controller) neural network to solve some color calibration problems, which include color differences induced from gamuts mis-match and the non-linear transformation characteristics between color scanning input devices and color printing output devices. For this purpose, we proposed a scalable learning architecture ''Cascade-CMAC'' to implement an adaptive color calibration system. By analyzing the preliminary learning situation, the scalable architecture can dynamically create a new learning unit to better represent a finer color resolution, so that the learning capacity as well as the color details of the system can be greatly improved. From the experimental results, the proposed Cascade-CMAC architecture can improve the rate of convergence and also can adjust the learning architecture effectively. The learning speed can be 2 similar to 4 times faster than the conventional CMAC. The effectiveness of this neural network has been tested by observing the differences between the calibrated and the un-calibrated output on a number of known samples. By using Macbeth Color-Checker which contains 24 color ptaches as benchmark, tile average color differences between the original and the calibrated print-out is improved from 15 Delta E-ab to 8 Delta E-ab under the 3 Delta E-ab convergent criterion for training. The calibration performance is somewhat significant.
Influence of the condenser on sample tracking via forward scattering pattern detection
(2004)
Tsai, CL
;
Chang, BJ
;
Huang, KL
;
Hsu, L
;
電子物理學系
Sample tracking with a high spatial sensitivity is highly desired in force measurement with optical tweezers. However, the trick that sample tracking via forward scattering pattern detection would provide a higher sensitivity than that via regular image detection has never been investigated. In this paper, we systematically study the influences of the position and the numerical aperture of the condenser on sample tracking via forward scattering pattern detection. In our experiment, a 60X condenser is used to form the forward scattering pattern of a sample bead upon a CCD camera. As the bead is transversely shifted at a step size of 30nm by a PZT XYZ stage, we measure the magnitude of the corresponding shift of the forward scattering pattern when the 60X condenser of different angular apertures is placed at various locations along the optical axis. Our result shows that the most sensitive forward scattering pattern occurs when the condenser collimates the forward scattering light from the sample bead. We also find that the larger the numerical aperture is, the higher the sensitivity of forward scattering pattern detection will be.
Performance analysis for serially concatenated FEC in IEEE802.16a over wireless channels
(2004)
Huang, KL
;
Hang, HM
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
To design an IEEE802.16a wireless transmission system, we investigate the performance of its serially concatenated forward error correction (FEC) system for both additive white Gaussian noise (AWGN) channel and the fully interleaved Rayleigh fading channel (FI-RFC). We derive the union upper bounds on the bit error rate (BER) for the Reed-Solomon (RS) code and the rate-compatible punctured convolutional codes (RCPC). These theoretical bounds are compared with the simulation results and it shows that the derived bounds are fairly tight. In addition, simulation results of the packet error rate (PER) are also presented. We thus in this paper provide researchers a suitable operational range of IEEE802.16a in terms of signal-to-noise ratio and acceptable performance.