A new threshold selection algorithm for multidimensional feature space is proposed, and its applications to colour images are shown. This algorithm is based on tho recursive application of a simple 1-D threshold selection method (valley detection) to the conditional 1-D histograms. Although the performance of the algorithm such as convergence rate etc. is not yet evaluated, uniform colour regions are successfully extracted by the proposed algorithm for several colour images. 相似文献
The purpose of this paper is to describe the implementation of monolithically matching circuits, interface circuits, and RF core circuits to the same substrate. We designed and fabricated on‐chip 1 to 6 GHz up‐conversion and 1 to 8 GHz down‐conversion mixers using a 0.8 µm SiGe hetero‐junction bipolar transistor (HBT) process technology. To fabricate a SiGe HBT, we used a reduced pressure chemical vapor deposition (RPCVD) system to grow a base epitaxial layer, and we adopted local oxidation of silicon (LOCOS) isolation to separate the device terminals. An up‐conversion mixer was implemented on‐chip using an intermediate frequency (IF) matching circuit, local oscillator (LO)/radio frequency (RF) wideband matching circuits, LO/IF input balun circuits, and an RF output balun circuit. The measured results of the fabricated up‐conversion mixer show a positive power conversion gain from 1 to 6 GHz and a bandwidth of about 4.5 GHz. Also, the down‐conversion mixer was implemented on‐chip using LO/RF wideband matching circuits, LO/RF input balun circuits, and an IF output balun circuit. The measured results of the fabricated down‐conversion mixer show a positive power conversion gain from 1 to 8 GHz and a bandwidth of about 4.5 GHz. 相似文献
Nitride-based flip-chip indium-tin-oxide (ITO) light-emitting diodes (LEDs) were successfully fabricated. It was found that the forward voltage and the 20 mA output power of the flip-chip ITO LED were 3.32 V and 14.5 mW, respectively. Although the operation voltage of such a flip-chip ITO LED was slightly larger, it was found that its output power was much larger than those of conventional nonflip-chip LEDs. It was also found that flip-chip ITO LEDs were more reliable. 相似文献
The mixed oxidation of nickel in gases containing both oxygen and chlorine has been investigated using the techniques of thermogravimetric
analysis and examination of the corrosion products by scanning electron microscopy. Two regimes of corrosion behavior have
been detected: one in which a protective oxide film is present and the rate of corrosion is controlled by the transport of
the volatile products of the reaction between the gas phase and the oxide, and one in which the protective film is penetrated
and corrosion occurs rapidly enough to result in the ignition of the specimen. The oxide corrosion products on the specimens
after corrosion have characteristic morphologies, with the products of volatilization type corrosion consisting of large grains
and the products of ignition type attack consisting of fine spherical particles. Ignition is a serious hazard in environments
containing 0.25 pct or more Cl2 and 4 pct or more O2 by volume at temperatures between 1000 K and 1100 K, but is not produced by exposures at higher temperatures. A model based
on the stability of the protective film in steady state corrosion is presented which can be used to predict the transition
from volatilization to ignition type attack. 相似文献
This paper concerns the following problem: given a set of multi-attribute records, a fixed number of buckets and a two-disk system, arrange the records into the buckets and then store the buckets between the disks in such a way that, over all possible orthogonal range queries (ORQs), the disk access concurrency is maximized. We shall adopt the multiple key hashing (MKH) method for arranging records into buckets and use the disk modulo (DM) allocation method for storing buckets onto disks. Since the DM allocation method has been shown to be superior to any other allocation methods for allocating an MKH file onto a two-disk system for answering ORQs, the real issue is knowing how to determine an optimal way for organizing the records into buckets based upon the MKH concept.
A performance formula that can be used to evaluate the average response time, over all possible ORQs, of an MKH file in a two-disk system using the DM allocation method is first presented. Based upon this formula, it is shown that our design problem is related to a notoriously difficult problem, namely the Prime Number Problem. Then a performance lower bound and an efficient algorithm for designing optimal MKH files in certain cases are presented. It is pointed out that in some cases the optimal MKH file for ORQs in a two-disk system using the DM allocation method is identical to the optimal MKH file for ORQs in a single-disk system and the optimal average response time in a two-disk system is slightly greater than one half of that in a single-disk system. 相似文献
A computer program to calculate the strip temperature heated in the continuous annealing furnace was developed, using the
zone method for radiative heat transfer analysis with the measured gas temperature in the furnace. Using theFE Operator, the present study considered the effects of soot and transient species, in addition to the H2O−CO2 gas mixture on the gas radiative heat transfer. The predicted strip temperature distribution forFE=1.05 represented well the measured data. The maximum difference in the heat flux transfered to the strip from the combustion
gas forFE=1.0 (without soot and transient species gas radiation) and 1.05 (with soot and transient species gas radiation) was about
15%. The present study also investigated the effects of line speed and thickness variations on the strip temperature, establishing
the bases for the on-line computer model. 相似文献