http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : J.N.D. Torrão (검색결과 3 건)
- 무료
- 기관 내 무료
- 유료
-
SPIF-A: on the development of a new concept of incremental forming machine
R.J. Alves de Sousa,J.A.F. Ferreira,J.B. Sá de Farias,J.N.D. Torrão,D.G. Afonso,M.A.B.E Martins 국제구조공학회 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.49 No.5
This paper presents the design and project of an innovative concept for a Single PointIncremental Forming (SPIF) Machine. Nowadays, equipment currently available for conducting SPIF resultmostly from the adaptation of conventional CNC machine tools that results in a limited range of applicationsin terms of materials and geometries. There is also a limited market supply of equipment dedicated toIncremental Sheet Forming (ISF), that are costly considering low batches, making it unattractive forindustry. Other factors impairing a quicker spread of SPIF are large forming times and poor geometricalaccuracy of parts. The following sections will depict the development of a new equipment, designed toovercome some of the limitations of machines currently used, allowing the development of a sounding basisfor further studies on the particular features of this process. The equipment here described possesses sixdegrees-of freedom for the tool, for the sake of improved flexibility in terms of achievable tool-paths and anextra stiffness provided by a parallel kinematics scheme. A brief state of the art about the existing SPIFmachines is provided to support the project’s guidelines.
-
An optimal-estimation-based aerosol retrieval algorithm using OMI near-UV observations
Jeong, U.,Kim, J.,Ahn, C.,Torres, O.,Liu, X.,Bhartia, P. K.,Spurr, R. J. D.,Haffner, D.,Chance, K.,Holben, B. N. Copernicus GmbH 2016 Atmospheric Chemistry and Physics Vol.16 No.1
<P>Abstract. An optimal-estimation(OE)-based aerosol retrieval algorithm using the OMI (Ozone Monitoring Instrument) near-ultraviolet observation was developed in this study. The OE-based algorithm has the merit of providing useful estimates of errors simultaneously with the inversion products. Furthermore, instead of using the traditional look-up tables for inversion, it performs online radiative transfer calculations with the VLIDORT (linearized pseudo-spherical vector discrete ordinate radiative transfer code) to eliminate interpolation errors and improve stability. The measurements and inversion products of the Distributed Regional Aerosol Gridded Observation Network campaign in northeast Asia (DRAGON NE-Asia 2012) were used to validate the retrieved aerosol optical thickness (AOT) and single scattering albedo (SSA). The retrieved AOT and SSA at 388 nm have a correlation with the Aerosol Robotic Network (AERONET) products that is comparable to or better than the correlation with the operational product during the campaign. The OE-based estimated error represented the variance of actual biases of AOT at 388 nm between the retrieval and AERONET measurements better than the operational error estimates. The forward model parameter errors were analyzed separately for both AOT and SSA retrievals. The surface reflectance at 388 nm, the imaginary part of the refractive index at 354 nm, and the number fine-mode fraction (FMF) were found to be the most important parameters affecting the retrieval accuracy of AOT, while FMF was the most important parameter for the SSA retrieval. The additional information provided with the retrievals, including the estimated error and degrees of freedom, is expected to be valuable for relevant studies. Detailed advantages of using the OE method were described and discussed in this paper. </P>
-
Optical properties of aerosol mixtures derived from sun‐sky radiometry during SAMUM‐2
TOLEDANO, C.,WIEGNER, M.,GROß, S.,FREUDENTHALER, V.,GASTEIGER, J.,MÜ,LLER, D.,MÜ,LLER, T.,SCHLADITZ, A.,WEINZIERL, B.,TORRES, B.,O'NEILL, N. T. Blackwell Publishing Ltd 2011 Tellus. Series B, Chemical and physical meteorolog Vol.63 No.4
<P><B>ABSTRACT</B></P><P>The SAMUM‐2 experiment took place in the Cape Verde islands in January–February 2008. The colocated ground‐based and airborne instruments allow the study of desert dust optical and microphysical properties in a closure experiment. The Meteorological Institute of the University of Munich deployed one sun‐sky photometer and two tropospheric lidar systems. A travelling AERONET‐Cimel sun‐sky radiometer was also deployed. During the measurement period the aerosol scenario over Cape Verde mostly consisted of a dust layer below 2 km and a smoke‐dust layer above 2–4 km a.s.l. The Saharan dust arrived at the site from the NE, whereas the smoke originated in the African equatorial region. This paper describes the main results of the Sun photometer observations, supported by lidar information. An analysis of the variations in the aerosol optical depth (AOD) in the range 340–1550 nm, the Ångström exponent, volume size distributions and single scattering albedo is presented. The aerosol mixtures are analysed by means of the fine mode fraction of the AOD provided by the sun‐sky inversion data and the Spectral Deconvolution Algorithm. The mean AOD (500 nm) was 0.31, with associated low Ångström exponent of 0.46. Several types of events were detected within the data set, with prevalence of dust or mixtures as characterized by the Ångström exponents of extinction and absorption and the fine mode fraction. Aerosol properties derived from sunphotometry were compared to in situ measurements of size distribution, effective radius and single scattering albedo.</P>
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
