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351.
The short-term wave characteristics are required for design and operation of industrial facilities within the coastal areas. Water surface displacement measured using waverider buoy moored at 13 m water depth in the eastern Arabian Sea off the west coast of India have been analyzed to study the short-term statistics of waves covering full one year period. The study indicates that the values of the observed maximum wave height as a function of duration are not consistent with the theoretical expected value. There is significant variation (1.29–2.19) in the ratio between highest 1% wave and significant wave height compared to the theoretical value of 1.67. The data recorded at 13 m water depth indicates that the significant wave height is ∼8% lower than that predicted by the conventional Rayleigh distribution. The theoretical bivariate log-normal distribution represents the joint distributions of wave heights and periods for the study area. 相似文献
352.
Long-term data sets are discussed for three locations – a southern North Sea location, where sea states are typically dominated by wind-sea conditions, a Northwest Shelf of Australia location, where sea states are often a mix of wind-sea and swell conditions, and a Guinea Gulf location offshore Nigeria, where sea states are dominated by swell. Various types of sea state statistics that have application to availability studies are presented; but databases of these type that also include wind and current data can also be used to estimate response parameters, which can give a more direct assessment of availability, and some example statistics of these are also given. Finally, the availability of offloading an FLNG barge to carrier is evaluated for each of the data sets, for specific operability criteria. Two types of operability criteria are used in the availability evaluations, and the results compared. 相似文献
353.
1996—2013年上海虹桥机场低能见度及低跑道视程特征分析 总被引:5,自引:0,他引:5
利用1996—2013年上海虹桥机场逐时地面观测资料,对影响机场正常运行的主导能见度低于800 m(低能见度)和跑道视程(RVR)低于550 m(低RVR)时次的出现次数进行统计分析,得到以下结论:1996—2013年虹桥机场除2002年低RVR时次出现较多外,其余年份均为低能见度时次出现更多;低能见度及低RVR时次出现次数分别以57次/年和26次/年的速率减少;季节变化特征显示两者均在12月出现最多,9月出现最少,11月至次年2月是两者出现的高频季节,5—9月为低频季节;一天中低能见度及低RVR多集中出现于19:00—01:00(世界时),其中23:00达各自峰值;进入夜间后低能见度时次的出现比率首先较大,后半夜开始低RVR影响逐渐凸显。虹桥机场低能见度时次出现次数随能见度数值的降低呈先减少后增多趋势,低RVR时次则在150~200 m及0~50 m两个区间出现次数较多。 相似文献
354.
X.‐F. Deng 《Astronomische Nachrichten》2015,336(10):1017-1024
In this study, I attempt to apply for a new statistical method and investigate the environmental dependence of stellar mass and stellar velocity dispersion in the CMASS sample of the Sloan Digital Sky Survey Data Release 9 (SDSS DR9). I divide the CMASS sample with redshifts 0.44 ≤ z ≤ 0.59 into many subsamples with a redshift binning size of Δz = 0.01, and analyze the environmental dependence of stellar mass and stellar velocity dispersion of subsamples in each redshift bin. It is found that stellar mass and stellar velocity dispersions of CMASS galaxies are very weakly correlated with the local environment. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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Tad W. Patzek 《Natural Resources Research》2006,15(3):205-212
This paper analyzes the Illinois State Variety Test results for total and extractable starch content in 708 samples of 401
commercial varieties of corn. It is shown that the normally distributed extractable starch content has the mean of 66.2% and
the standard deviation of 1.13%. The corresponding maximum theoretical yield of ethanol is 0.364 kg EtOH/kg dry corn, and
the standard deviation is 0.007. In the ethanol industry units, this yield translates to 2.64 gal EtOH/nominal wet bushel,
and the standard deviation is 0.05 gal/bu.
The U.S. ethanol industry consistently has inflated its ethanol yields by counting 5 volume percent of # 14 gasoline denaturant
(8% of energy content) as ethanol. Also, imports from Brazil and higher alcohols seem to have been counted as U.S. ethanol.
The usually accepted USDA estimate of mean ethanol yield in the U.S., 2.682 gal EtOH/bu, is one standard deviation above the
rigorous statistical estimate in this paper.
相似文献
Tad W. PatzekEmail: |
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360.
基于局部空间统计的产业集群空间分析——以北京市制造业集群为例 总被引:4,自引:2,他引:2
将集群识别与空间分析相结合,通过全国集群模板识别产业集群,进而利用局部空间统计方法,探测产业集群的空间布局特征。利用2008年北京市和全国经济普查数据,从产业联系的角度识别了北京市制造业集群,在此基础上进一步测度了北京市制造业集群的空间分布现状与布局特征。研究发现,北京市制造业集群主要分布在近郊区并向远郊区延伸,资源条件、政策环境、交通区位、历史因素等多种区位因子均对集群的区位选择产生影响。从总体分布来看,北京市制造业集群的空间布局存在分布比较分散、功能重叠或与区县功能定位不符等问题。未来在政策制定时,应进一步强化北京市制造业集群的空间集聚,发挥区域产业政策的引导作用,并不断依托产业园区优化集群发展环境,引导符合区县功能定位的制造业集群发展。 相似文献