Angular memory and frequency interferometry for mean heightprofiling of a rough surface

The polarimetric angular memory effect is applied to obtain the average topographic height of a rough surface. This novel effect improves the height sensitivity while maintaining a good degree of correlation between the sensors. By using a reference flat surface, the interferometric phase is linearly related to the mean topographic height. The combination of angular memory and wideband frequency interferometry (AMFI) is realized and offers a means to design a robust interferometric system. Extension of the technique to the pulse scattering problem is studied through the two-frequency mutual coherence function, and its time-domain transform provides an equivalent way to obtain the mean topographic height by combining both spatial and temporal diversity. Millimeter-wave (MMW) experiments are conducted with rough surfaces of different statistics and scattering media of different types (gravel, sand, and rough surfaces) to prove the effectiveness of the technique     

Constituents isolated from Glehnia littoralis suppress proliferations of human cancer cells and MMP expression in HT1080 cells

Crude extract and solvent-partitioned fraction of Glehnia littoralis were found to possess different anti-proliferative effects against AGS, HT1080 and U937 human cancer cells. The crude extracts and solvent fractions dose-dependently inhibited cell proliferation. Especially, n-hexane and 85% aqueous MeOH fractions exhibited comparatively higher anti-proliferative effects and reduced expressions of Bcl-2, COX-2 and iNOS genes. Systematic separation of all solvent fractions by chromatographic methods led to the isolation of three glucopyranosides, four furanocoumarins and two polyacetylenic alcohols. All the nine compounds were evaluated for their inhibitory effects against both proliferation of human cancer cells and expressions of MMP-2 and -9 in HT1080 cells. Two polyacetylenic alcohols exerted the highest inhibitory activity against both human cancer cell lines, and MMP-2 and -9. These results suggest that G. littoralis may possibly be used as a valuable chemopreventive agent or food supplement for reducing cancer risk.     

Resampling, Antialiasing, and Compression in Multiview 3-D Displays

Multiview three-dimensional (3-D) displays offer viewing of high-resolution stereoscopic images from arbitrary positions without glasses. This article surveyed different approaches to develop signal processing algorithms for these displays. Such displays consist of view-dependent pixels that reveal a different color according to the viewing angle. Therefore, the left and right eye of an observer sees slightly different images on the screen. This leads to the perception of 3-D depth and parallax effects when the observer moves. Although the basic optical principles of multiview auto-stereoscopy have been known for over a century, only recently displays with increased resolution, or systems based on multiple projectors, have made this approach practical.     

Gas-phase driven nano-machined TiO2 ceramics

A simple, inexpensive gas phase reaction termed as “nanocarving process” converts TiO₂ grains into arrays of single crystal nanofibers by selective and anisotropic etching. This process is conducted by exposing dense polycrystalline TiO₂ to a H₂/N₂ environment at 700 °C. The dimensions of nanofibers are around 20 nm in diameter and 1 μm in length. The preferred crystallographic orientation for the nanocarving process is the <001> direction. Nanoparticles composed of Fe and Ni were observed on the surface of TiO₂ that formed nanofiber tips. Sintering parameters before the nanocarving treatment play a critical role in the formation of nanofibers. As sintering temperature and time increased, the rate of nanofiber generation decreased. Moreover, it was observed that by varying the heat treatment conditions, it is possible to create other structures like nanowhiskers and nanofilaments. Nanowhiskers were formed by reoxidation of nanofiber-formed TiO₂ over 600 °C. Nano-filaments were generated by heat treating sintered TiO₂ in N₂-carrying water vapor at 700 °C.     

Production planning in semiconductor wafer fab considering variable cycle times

Recent research in the semiconductor manufacturing area has addressed some industrial engineering and operations research applications to solve the challenging production planning and scheduling problems. Relative to the other industries, the number of practical production management techniques and supporting software in the semiconductor industry is limited. The conventional models proposed use fixed or averaged cycle time and yield to get the results. However, in the actual wafer fabs, cycle time is spread widely and skewed due to the large variations in the operations. Therefore, the use of averaged cycle time and yield makes significant differences between the plan and the actual shop performance. Thus, we focus on the production planning problem in the wafer fabrication (“fab”), introducing a planning methodology that explicitly considers the variable cycle time and the shop status. We also evaluate some different types of input policies.     

NEURAL NETWORK-BASED PREDICTIVE CONTROL FOR MULTIVARIABLE PROCESSES

In this paper, the systematic derivations of setting up a nonlinear model predictive control based on the neural network are presented. This extends our previous work (Chen, 1998) into a multivariable system to explore the characteristics of the design. There are two stages for the development of nonlinear neural network predictive control: a neural network model and a control design. In the neural network model design, a parallel multiple-input, single-output neural network autoregressive with a model of exogenous inputs (NNARX) is proposed for multistep ahead predictions. In control design, the controller with extended control horizon is developed. The Levenberg-Marquardt algorithm is applied to training the NNARX model. Also, the sequential quadratic programming is used to search for the optimal manipulated inputs. The gradient of the objective function and constraints that require computation of Jacobian matrices are completely derived for optimization calculation. To demonstrate the control ability of MIMO cases, the proposed method is applied through two nonlinear simulation problems.     

海洋放线菌发酵产物的乙酰胆碱酯酶抑制活性研究

利用海洋高氏一号培养基对36株海洋放线菌进行培养。发酵处理4 d天后发酵液用乙酸乙酯进行提取。用Ellman法检测发酵产物的乙酰胆碱酯酶抑制活性。21株海洋放线菌的发酵产物对乙酰胆碱酯酶具有显著的抑制活性,其中,放线菌LYG22对乙酰胆碱酯酶的抑制活性最好,对AChE的抑制率达到48.58%。