Motion-based grouping of optical flow fields: the extrapolation andsubtraction technique

The goal of three-dimensional (3-D) motion segmentation is to identify the image areas projected by different moving objects in 3-D space. However, many prevailing methods merely detected the discontinuity of optical flow field and usually considered these boundaries as that produced by different 3-D motions. In fact, the flow discontinuity can be generated either by two different 3-D motions or by the structural discontinuity on the same moving object. The wrong identification causes several problems in 3-D motion estimation. A simple method called the extrapolation and subtraction (ES) technique is proposed to solve these problems. The input image flow field is first partitioned into several functionally analytic regions. Each analytic region is assumed to be projected by a roughly planar patch moving in 3-D space. Based on the parameterization of these analytic flow fields, the ES technique provides a very simple and fast method to test the 3-D motion compatibility between two interested analytic flow fields.     

Handprinted character recognition based on spatial topologydistance measurement

In this work we present a self-organization matching approach to accomplish the recognition of handprinted characters drawn with thick strokes. This approach is used to flex the unknown handprinted character toward matching its object characters gradually. The extracted character features used in the self-organization matching are center loci, orientation, and major axes of ellipses which fit the inked area of the patterns. Simulations provide encouraging results using the proposed method     

Optimization of on-chip ESD protection structures for minimal parasitic capacitance

Diodes are key components in on-chip electrostatic discharge (ESD) protection design. As the operating frequency of the microchip being protected against the ESD continues to increase, the parasitic capacitance associated with the diodes in the ESD structure starts to impose problems for RF operation. This paper presents a systematic approach to optimize the diode structure for minimal parasitic capacitance based on the requirements of breakdown voltage and heat dissipation. Device simulator Atlas with mix-mode simulation capability is calibrated against measurement data and used to carry out the optimization. An optimized diode structure with a parasitic capacitance of less than 30 fF at an operating frequency of 10 GHz and ESD charging voltage of 1 kV has been suggested. Furthermore, a case study to implement and optimize the ESD protection structure based on an existing 0.13-μm CMOS technology has been presented and verified.     

Fabrication and field emission properties of ultra-nanocrystalline diamond lateral emitters

Field emission characteristics of ultra-nanocrystalline diamond (UNCD) have recently caught much attraction due to its importance in technological applications. In this work, we have fabricated lateral-field emitters comprised of UNCD films, which were deposited in CH₄/Ar medium by microwave plasma-enhanced chemical vapor deposition method. The substrates, silicon-on-insulator (SOI) or SiO₂-coated silicon, were pre-treated by mixed-powders-ultrasonication process for forming diamond nuclei to facilitate the synthesis of UNCD films on these substrates. Lateral electron field emitters can thus be fabricated either on silicon-on-insulator (SOI) or silicon substrates. The lateral emitters thus obtained possess large field enhancement factor (β = 1500–1721) and exhibit good electron field emission properties, regardless of the substrate materials used. The electron field emission can be turned on at 5.25–5.50 V/μm, attaining 5500–6000 mA/mm² at 12.5 V/μm (100 V applied voltage).     

Improved and physics-based model for symmetrical spiral inductors

Recent growth in RF applications has increased the use of spiral inductors and thus demanded a more accurate model for such devices. In this paper, the authors focus on the model development of spiral inductors with symmetrical terminals, but the same approach can be applied readily to asymmetrical inductors. Relevant and important physics such as the current crowding in metal line, frequency-dependent permittivity in oxide, and overlap parasitics are accounted for. Experimental data and results calculated from the existing inductor models are included in support of the model development.     

Mode stability of a two-wavelength Fabry-Perot/distributed-feedbacklaser

A theory based on a Fokker-Planck equation has been developed to analyze the two-mode operation of a Fabry-Perot/distributed-feedback (FP/DFB) laser. Simultaneous oscillation of the DFB mode and the FP mode near the gain peak with negligible mode power fluctuation can be achieved if the DFB mode is detuned sufficiently from the gain peak. Calculated results for the design of stable two-wavelength lasers are presented     

An improved model for four-terminal junction field-effecttransistors

The junction field-effect transistor (JFET) has isolated top- and bottom-gate terminals and therefore is useful for signal mixing applications. Existing models for the four-terminal JFET often have the same form as the three-terminal JFET model, however, in which only a single pinch-off voltage is used to describe the current-voltage characteristics. In this paper, a more general four-terminal JFET model is developed. Two different pinch-off voltages are involved in the improved model to account more comprehensively for the effects of both depletion regions associated with the top- and bottom-gate junctions. Results simulated from a device simulator are also included in support of the model     

Diels-Alder Reaction of [60]Fullerene with Dienes Having an Ester Substituent at 1-Position

Treatment of [60]fullerene with ethyl trans, trans-hexa-2,4-dienoate (1) and methyl trans, trans-octa-2,4-dienoate (2) at 70 ∼ 100 °C afforded products 3 and 4, respectively, which are resulted from Diels-Alder addition of the dienoates to a 6/6 ring junction of [60]fullerene.     

An expert system for respirator selection

A Respirator Selection Expert System (RSES) is described which assists the user in selection of a respirator for a specific application. In addition to determining the minimum class of respirator which should be used by following the NIOSH Respirator Decision Logic, RSES also provides all necessary calculations, data for common industrial contaminants and on-line reference material.