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排序方式: 共有595条查询结果,搜索用时 15 毫秒
41.
Grasso S Bellucci M Cocorullo G Della Corte FG Lodice M Rendina I 《Applied optics》2002,41(18):3601-3612
Rendina et al. recently proposed the original configuration of an electromagnetic power sensor for microwaves and millimeter waves that is based on an optically interrogated all-silicon chip [Electron. Lett. 35, 1748 (1999)]. Here we theoretically analyze and discuss in detail the performances of such a new class of nonperturbing and wideband probe in terms of sensitivity, resolution, intrinsic detectivity, linearity, and response time. Good agreement between theory and experiments is demonstrated. In particular, minimum resolutions of approximately 1 mW/cm2 are obtained at frequencies beyond 10 GHz. The dependence of response on the geometrical and electromagnetic parameters of the sensing element is analyzed, and on this basis the possibility of achieving optimized configurations is discussed. 相似文献
42.
A Scalable Architecture for MPEG-4 Wavelet Quantization 总被引:3,自引:0,他引:3
Bart Vanhoof Mercedes Peón Gauthier Lafruit Jan Bormans Lode Nachtergaele Ivo Bolsens 《The Journal of VLSI Signal Processing》1999,23(1):93-107
Wavelet-based image compression has been adopted in MPEG-4 for visual texture coding. All wavelet quantization schemes in MPEG-4—Single Quantization (SQ), Multiple Quantization (MQ) and Bi-level Quantization—use Embedded Zero Tree (EZT) coding followed by an adaptive arithmetic coder for the compression and quantization of a wavelet image. This paper presents the OZONE chip, a dedicated hardware coprocessor for EZT and arithmetic coding. Realized in a 0.5 m CMOS technology and operating at 32 MHz, the EZT coder is capable of processing up to 25.6 Mega pixel-bitplanes per second. This is equivalent to the lossless compression of 31.6 8-bit grayscale CIF images (352 × 288) per second. The adaptive arithmetic coder processes up to 10 Mbit per second. The combination of the performance of the EZT coder and the arithmetic coder allows the OZONE to perform visual-lossless compression of more than 30 CIF images per second. Due to its novel and scalable architecture, parallel operation of multiple OZONEs is supported. The OZONE functionality is demonstrated on a PC-based compression system. 相似文献
43.
Ivo Babuska Barna Szabo 《International journal for numerical methods in engineering》1982,18(3):323-341
The rate of convergence of the finite element method is a function of the strategy by which the number of degrees-of-freedom are increased. Alternative stragegies are examined in the light of recent theoretical results and computational experience. 相似文献
44.
Manes F De Santis F Giannini MA Vazzana C Capogna F Allegrini I 《The Science of the total environment》2003,308(1-3):133-141
An ozone monitoring network was set up using passive samplers and biological mini-stations of two clones of white clover (Trifolium repens L. cv. Regal), NC-R (O(3)-resistant) and NC-S (O(3)-sensitive). This paper reports on a pilot study performed in the period June-October 1999 in the Rome municipal area by using five biomonitoring mini-stations and ozone passive samplers with a new nitrite based design. This combined methodology can be used to obtain information on the biological implications of the injury due to tropospheric ozone. The two techniques can integrate data for the short-medium period and can be placed in different urban and rural sites, proving to be a very useful tool for ozone concentration mapping. 相似文献
45.
Matthias Schirmer Doris Perseke Eva Zena Daniel Schondelmaier Ivo Rudolph Bernd Loechel 《Microsystem Technologies》2007,13(3-4):335-338
A variety of different photo resists are used for fabrication of MEMS. Presently good results were reported for SU-8, a chemically
amplified negative tone photoresist. But SU-8 has a disadvantage for some applications in LIGA technique, especially in the
X-ray mask fabrication. After processing the finished resist pattern are hardly soluble from the substrate. This paper will
briefly describe the current status of the development of the new negative tone photoresist CAR 44 whose big advantage is
the easy removableness of the cross linked pattern.
This work widely uses the contents of the presentation “A New Removable Resist for High Aspect Ratio Applications” to the
High Aspect Ratio Micro Structure Technology workshop HARMST 2005 held in Gyeongyu (Republic of Korea), June 10–13, 2005. 相似文献
46.
Theofanis Strouboulis Lin Zhang Ivo Babuška 《International journal for numerical methods in engineering》2007,69(2):250-283
In this paper, we address the cost versus accuracy capabilities for the generalized FEM (GFEM) which was developed in (Comput. Methods Appl. Mech. Eng. 2003; 192 :3109–3161, Int. J. Numer. Meth. Engng 2004; 60 :1639–1672, Ph.D. Thesis, Texas A&M University, College Station, TX, August 2003 (Advisor: T. Strouboulis)), and also the construction of two‐sided a posteriori error estimates, which can be used to assess the achieved accuracy at all levels of the method. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
47.
48.
Fábio J.B. Brum Sandro C. Amico Ivo Vedana Jaime A. Spim 《Journal of Materials Processing Technology》2009,209(7):3166-3171
Autoclave processing is commonly used nowadays for dewaxing in the investment casting process. However, since the use of microwave is steadily growing in industrial processes and the wax interacts with the electromagnetic energy of the microwaves, the present work studies the possibility of carrying out dewaxing via microwave. The wax (mineral wax, vegetable resin, low molecular-weight polymer and anti-oxidant) used in this work was prepared by melting in an oven equipped with a mineral oil bath. The chemical and structural stability of the wax were monitored throughout 12 simulated dewaxing cycles, via various analyses, namely, volumetric expansion, hardness, Fourier transform infrared spectroscopy, ultraviolet–visible spectrophotometry, differential scanning calorimetry and viscosity. The results showed that microwave dewaxing is viable, significantly decreasing the incorporation of dirt and water, which is inevitable in the autoclave dewaxing process. 相似文献
49.
Finely ground titanium slag (–400 mesh) dissolves slowly in dilute H2SO4 (2–10 mol/L) in the temperature range 70–110°C, but attrition ground slag dissolves much faster under similar conditions. The process is strongly dependent on the speed of agitation in the region 345–1035 rpm, and has an activation energy of 28 kJ/mole TiO2, thus suggesting that the dissolution is controlled by diffusion through the boundary layer. 相似文献
50.
Antonela Dima Francesco Della Corte Ivo Rendina Mihai O. Dima 《Microelectronics Journal》2007,38(12):1169-1174
Development of memories based on organic soft materials is a current industrial niche aimed at the upper contacts flash memories. The electrical bistability of such materials makes them ideal candidates for cost-effective, fast-programming switching devices. Hybrid thin films of SiO2 with Rose Bengal (bis-triethylammonium) dopant are here reported for the first time, together with their characterisations. Technology-wise the main advantage of the films is the possibility to cast photolithographically, which is also cost-effective. The physical and chemical stability of the films yields reproducible devices, from both the microtechnological and electrical point of view. 相似文献