144,107 research outputs found
Control and Filtering for Discrete Linear Repetitive Processes with H infty and ell 2--ell infty Performance
No full textRepetitive processes are characterized by a series of sweeps, termed passes, through a set of dynamics defined over a finite duration known as the pass length. On each pass an output, termed the pass profile, is produced which acts as a forcing function on, and hence contributes to, the dynamics of the next pass profile. This can lead to oscillations which increase in amplitude in the pass to pass direction and cannot be controlled by standard control laws. Here we give new results on the design of physically based control laws for the sub-class of so-called discrete linear repetitive processes which arise in applications areas such as iterative learning control. The main contribution is to show how control law design can be undertaken within the framework of a general robust filtering problem with guaranteed levels of performance. In particular, we develop algorithms for the design of an H? and dynamic output feedback controller and filter which guarantees that the resulting controlled (filtering error) process, respectively, is stable along the pass and has prescribed disturbance attenuation performance as measured by and – norms
Ctenosciara mutisetosa Wu & Zhang, sp. nov.
No full textCtenosciara mutisetosa Wu & Zhang sp. nov. Fig. 1 A–E Specimens examined. Holotype, male. China, Yunnan province, Tengchong, Jietou, Shaba, Mt. Tiantaishan, 2142 m, 25 ° 24.524 ΄N, 98 ° 42.735 ΄E, sweep-net, 13.V. 2009, Su-Jiong Zhang [SM00927]. Paratypes. 1 male, same data as holotype [SM00924]. Mid leg lost in the holotype. Description (Male). Body length: 1.68 mm. Color. Antenna bicolored, flagellomeres brown, scape and pedicel yellow; thorax, abdomen, hypopygium, and coxae yellowish-brown; palpus and legs yellow; wing fumose. Head (Fig. 1 A, B). Eye bridge three facets wide. Prefrons with 17 setae. Basal segment of palpus with three setae, with an indistinct sensory pit; 2 nd segment with eight setae; 3 rd segment with eight setae. Length of 4 th flagellomere: 0.13 mm, length/width: 2.70. Thorax. Anterior pronotum with four setae, episternum 1 with seven setae. Apex of fore tibia with a comb-like row of setae, subdivided into two parts (Fig. 1 C). Length of spur/width of tibia: fore leg 2.00. Length of metatarsus/length of tibia: fore leg 0.79, hind leg 0.48. Length of hind tibia/length of thorax: 1.76. Tarsal claws not toothed. Wings (Fig. 1 D). Wing length 1.87 mm, width/length: 0.43. CuA 1, CuA 2, and r-m with dorsal setae. bM bare. R 1, R 5, M 1, and M 2 with both dorsal and ventral setae along their entire length. stM weakly visible, with some setae. Haltere with one row of setae. c/w: 0.70. R 1 /R: 0.97. r-m/bM: 1.43. Hypopygium. Gonostylus rather slender, attenuated apically, and with apical tooth and six subapical megasetae (Fig. 1 F). Tegmen longer than broad, with very fine aedeagal teeth; aedeagal apodeme slender (Fig. 1 E). Female. Unknown. Remarks. The species is similar to C. constrictans (Edwards, 1927) in having dorsal setae on r-m, stM, and CuA 2, and both dorsal and ventral setae on R 1, R 5, M 1, and M 2. However, it is distinguished by having a gonostylus that is slender and attenuated apically, while C. constrictans is almost equally wide along entire length. Additionally, length/width of the 4 th flagellomere is 2.70 in the new species, while it is 4 in C. constrictans. Moreover, the body length of C. mutisetosa was 1.68 mm, which is much smaller than C. constrictans, which was about 3 mm. Etymology. This species is named after its setose ventral R 1, M 1, and M 2 veins.Published as part of Wu, Hong, Zhang, Su-Jiong & Huang, Junhao, 2010, The genus Ctenosciara Tuomikoski in China, with descriptions of three new species (Diptera, Sciaridae), pp. 42-50 in Zootaxa 2560 on page 44, DOI: 10.5281/zenodo.19701
Discovery of an optical counterpart to the hyperluminous X-ray source in ESO 243-49
No full textThe existence of black holes of masses similar to 10(2)-10(5)M(circle dot) has important implications for the formation and evolution of star clusters and supermassive black holes. One of the strongest candidates to date is the hyperluminous X-ray source (HLX1), possibly located in the S0- a galaxy ESO 243-49, but the lack of an identifiable optical counterpart had hampered its interpretation. Using the Magellan telescope, we have discovered an unresolved optical source with R = 23.80 +/- 0.25 mag and V = 24.5 +/- 0.3 mag within HLX1's positional error circle. This implies an average X-ray/optical flux ratio similar to 500. Taking the same distance as ESO 243-49, we obtain an intrinsic brightness M-R = -11.0 +/- 0.3 mag, comparable to that of a massive globular cluster. Alternatively, the optical source is consistent with a main-sequence M star in the Galactic halo (for example an M4.4 star at approximate to 2.5 kpc). We also examined the properties of ESO 243-49 by combining Swift/Ultraviolet/Optical Telescope (UVOT) observations with stellar population modelling. We found that the overall emission is dominated by a similar to 5-Gyr-old stellar population, but the UV emission at approximate to 2000 angstrom is mostly due to ongoing star formation at a rate of similar to 0.03M(circle dot) yr(-1). The UV emission is more intense (at least a 9 sigma enhancement above the mean) north-east of the nucleus, in the same quadrant as HLX1. With the combined optical and X-ray measurements, we put constraints on the nature of HLX1. We rule out a foreground star and a background AGN. Two alternative scenarios are still viable. HLX1 could be an accreting intermediate mass black hole in a star cluster, which may itself be the stripped nucleus of a dwarf galaxy that passed through ESO 243-49, an event which might have caused the current episode of star formation. Or, it could be a neutron star in the Galactic halo, accreting from an M4-M5 donor star
Ctenosciara pseudoinsolita Wu & Zhang, sp. nov.
No full textCtenosciara pseudoinsolita Wu & Zhang sp. nov. Fig. 2 A–F Specimens examined. Holotype, male. China, Zhejiang province, Wenzhou, Taishun, Wuyanling Nature Reserve, 700 m, 27 ° 21.193 ΄N, 119 ° 38.133 ΄E, malaise trap, 20.VII. 2005, Xiao-Qing Cheng [SM00813]. Paratype. 1 male, China, Zhejiang province, Lishui, Mt. Fengyangshan, plant nursery, 28 °04΄N, 119 °08΄E, malaise trap, 12.VII. 2007, Sheng-Long Liu [SM00293]. Description (Male). Body length: 3.02 mm. Color. Antenna brown; thorax, abdomen, hypopygium, and coxae yellowish-brown; palpus and legs yellow; wing fumose. Head (Fig. 2 A, B). Eye bridge three facets wide. Prefrons with 16 setae. Palpus three-segmented, basal segment with four setae and an indistinct sensory pit, 2 nd segment with ten setae, 3 rd segment with ten setae. Length of 4 th flagellomere: 0.14 mm, length/ width: 3.55. Thorax. Anterior pronotum with three setae, episternum 1 with six setae. Apex of fore tibia with a comb-like row of setae, and subdivided into two part (Fig. 2 C). Length of spur/width of tibia: fore leg 1.84. Length of metatarsus/length of tibia: fore leg 0.60, mid leg 0.58, hind leg 0.52. Length of hind tibia/length of thorax: 1.45. Tarsal claws not toothed. Wings (Fig. 2 D). Wing length 2.24 mm, width/length: 0.42. M 1, M 2, CuA 1, CuA 2, and r-m with dorsal setae. bM bare. R 5 with dorsal and ventral setae only on the apical third. stM well visible, with dorsal setae. Halter with two rows of setae. c/w: 0.72. R 1 /R: 0.97. r-m/bM: 1.27. Hypopygium. Gonostylus rather slender, slightly attenuated apically, and with an apical tooth and four subapical megasetae (Fig. 2 F). Tegmen attenuated at apex, with no distinct aedeagal teeth; aedeagal apodeme long (Fig. 2 E). Female. Unknown. Remarks. This species is similar to C. insolita (Sasakawa, 1994) in having unicolor antenna; 4–5 setae on basal segment of palpus; r-m, stM, and CuA 2 with setae; R 1 nearly as long as R and subequal body length. It differs from C. insolita by having R 5 with dorsal and ventral setae only on the apical third, claws not toothed and tegmen attenuated at the apex. The most obvious difference is in the subapical megasetae of the gonostylus: the new species has four, while C. insolita has 7–9. Etymology. The species is named after its similarity to C. insolita.Published as part of Wu, Hong, Zhang, Su-Jiong & Huang, Junhao, 2010, The genus Ctenosciara Tuomikoski in China, with descriptions of three new species (Diptera, Sciaridae), pp. 42-50 in Zootaxa 2560 on pages 44-47, DOI: 10.5281/zenodo.19701
Selective amplification of frequency comb modes via optical injection locking of a semiconductor laser: influence of adjacent unlocked comb modes
No full textOptical injection locking can be used to isolate and amplify individual comb modes from an optical frequency comb (OFC). However, it has been observed that for narrow spaced OFCs (e.g. 250 MHz), the adjacent comb modes are still present in the output of the locked laser. These residual modes experience some amplification relative to the injected signal, however the gain is significantly less than for the locked mode. We report the measurement of this sidemode amplification for a semiconductor laser injection locked to a 250 MHz spaced OFC. It was found that this amplification can be well suppressed by tuning the frequency difference between the free running laser and the OFC mode it was locked to. The sidemode amplification was then investigated numerically by solving the laser rate equations under optical injection. It was found that the main contribution to the sidemode amplification was due to phase modulation induced by the residual comb modes. The detuning dependent suppression occurs due to destructive interference between pairs of equidistant comb modes
Minimum R Squared Method (MRS)
No full textVersion 20200220
Minimum R Square Method (MRS) initially proposed by Millet et al. (2005) is a useful method to determine the primary ratio in the tracer method. The purpose of the program is to feasible MRS calculation via a user-friendly GUI. The MRS application is not limited in OC/EC tracer method, but can also be extended to other applications as long as a reliable tracer is available.
MRS calculation can be done by different temporal cycles (batch calculation): by year, by year&season, by season, by year&month, by month, by year&month&hour. Data filter is also available to calculate MRS on a specific subset of data.
For more details regarding the evaluation of the MRS method, please refer to
Wu, C. and Yu, J. Z.: Determination of primary combustion source organic carbon-to-elemental carbon (OC / EC) ratio using ambient OC and EC measurements: secondary OC-EC correlation minimization method, Atmos. Chem. Phys., 16, 5453-5465, doi:10.5194/acp-16-5453-2016, 2016.
Wu, C., Wu, D., and Yu, J. Z.: Quantifying black carbon light absorption enhancement with a novel statistical approach, Atmos. Chem. Phys., 18, 289-309, doi:10.5194/acp-18-289-2018, 2018.
Please cite these two papers if MRS is used in your publication.
The latest version of the program can be found on my website:
https://sites.google.com/site/wuchengust/
https://wucheng.weebly.com
List of programs I developed:
ScatterPlot
Histogram and Boxplot
MRS
RT-ECOC raw data processor
Benchtop Sunset ECOC analyzer data processor
DRI 2001A data Sorter
SMPS Toolkit
Mie Scattering
Aethalometer data correction
MRS approach adoption in literature:
Sun, J. Y., Wu, C., Wu, D., Cheng, C., Li, M., Li, L., Deng, T., Yu, J. Z., Li, Y. J., Zhou, Q., Liang, Y., Sun, T., Song, L., Cheng, P., Yang, W., Pei, C., Chen, Y., Cen, Y., Nian, H., and Zhou, Z.: Amplification of black carbon light absorption induced by atmospheric aging: temporal variation at seasonal and diel scales in urban Guangzhou, Atmos. Chem. Phys., 20, 2445-2470, doi: https://doi.org/10.5194/acp-20-2445-2020, 2020.
Kaskaoutis, D. G., Grivas, G., Theodosi, C., Tsagkaraki, M., Paraskevopoulou, D., Stavroulas, I., Liakakou, E., Gkikas, A., Hatzianastassiou, N., Wu, C., Gerasopoulos, E., and Mihalopoulos, N.*: Carbonaceous Aerosols in Contrasting Atmospheric Environments in Greek Cities: Evaluation of the EC-tracer Methods for Secondary Organic Carbon Estimation, Atmosphere, 11, 161, doi: https://doi.org/10.3390/atmos11020161, 2
Wu, C., Wu, D., and Yu, J. Z*.: Estimation and Uncertainty Analysis of Secondary Organic Carbon Using One‐Year of Hourly Organic and Elemental Carbon Data. J. Geophys. Res.-Atmos, 124, 2774-2795 doi:https://doi.org/10.1029/2018JD029290, 2019
Ji, D., Gao, M., Maenhaut, W., He, J., Wu, C., Cheng, L., Gao, W., Sun, Y., Sun, J., Xin, J., Wang, L., and Wang, Y.: The carbonaceous aerosol levels still remain a challenge in the Beijing-Tianjin-Hebei region of China: Insights from continuous high temporal resolution measurements in multiple cities, Environment International, 126, 171-183, doi: https://doi.org/10.1016/j.envint.2019.02.034, 2019.
Ying, Q., Feng, M., Song, D., Wu, L., Hu, J., Zhang, H., Kleeman, M. J., and Li, X.: Improve regional distribution and source apportionment of PM2.5 trace elements in China using inventory-observation constrained emission factors, Sci.Total.Environ., 624, 355-365, doi: https://doi.org/10.1016/j.scitotenv.2017.12.138 2018.
Ji, Y., Qin, X., Wang, B., Xu, J., Shen, J., Chen, J., Huang, K., Deng, C., Yan, R., Xu, K., and Zhang, T.: Counteractive effects of regional transport and emission control on the formation of fine particles: a case study during the Hangzhou G20 summit, Atmos. Chem. Phys., 18, 13581-13600, https://doi.org/10.5194/acp-18-13581-2018, 2018.
Bian, Q., Alharbi, B., Shareef, M. M., Husain, T., Pasha, M. J., Atwood, S. A., and Kreidenweis, S. M.: Sources of PM2.5 carbonaceous aerosol in Riyadh, Saudi Arabia, Atmos. Chem. Phys., 18, 3969-3985, doi: https://doi.org/10.5194/acp-18-3969-2018, 2018.
Xu, J., Wang, Q., Deng, C., McNeill, V. F., Fankhauser, A., Wang, F., Zheng, X., Shen, J., Huang, K., and Zhuang, G.: Insights into the characteristics and sources of primary and secondary organic carbon: High time resolution observation in urban Shanghai, Environ Pollut, https://doi.org/10.1016/j.envpol.2017.10.003, 2017.
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由Millet (2005)最初提出的最小相关系数法(MRS)是确定性示踪法中的一次比值的有效方法。本程序的目的是通过一个用户友好的图形界面来执行MRS计算。MRS的应用不仅限于OC/ EC示踪法,只要一个可靠示踪物,就可扩展到其他的应用中(例如计算黑碳吸光增强系数Eabs)。
本程序的MRS计算可以通过不同的时间维度(批处理计算)来完成:年,年/季,季,年/月,月,按年及月和小时。数据筛选功能也被提供了用以抓去特定的数据子集进行MRS计算。
详情关于MRS方法的模式论证及应用,请参考 (如果你在文章中用到了本软件,请引用以下文章)
Wu, C. and Yu, J. Z.: Determination of primary combustion source organic carbon-to-elemental carbon (OC / EC) ratio using ambient OC and EC measurements: secondary OC-EC correlation minimization method, Atmos. Chem. Phys., 16, 5453-5465, doi:10.5194/acp-16-5453-2016, 2016.
Wu, C., Wu, D., and Yu, J. Z.: Quantifying black carbon light absorption enhancement with a novel statistical approach, Atmos. Chem. Phys., 18, 289-309, doi:10.5194/acp-18-289-2018, 2018.
本程序的相关信息可以在我的网站找到:
https://www.x-mol.com/groups/wucheng
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Identification of the novel KI and WU polyomaviruses in human tonsils
No full textThree novel polyomaviruses have been recently discovered: KI, WU and MC polyomaviruses. Their role in human pathology is debated while tissue tropism and site of latency remain unknown
Thermal expansion anomalies of R(Fe, M)(12) (R=Y, Nd; M=Mo and Si)
No full textStructural and thermal-expansion anomaly studies on R(Fe,M)(12) (R=Nd and and Y, M=Mo and Si) compounds were performed by x-ray diffraction. Mo atoms occupy the 8i site. While Si atoms occupy the 8f and 8j sites but not the 8i site. Thermal-expansion anomaly shows only in ab plane in the Mo compounds, while becomes very weak and along with only the c axis in the Si compounds. The anomaly was attributed to the contribution of the interactions of short Fe-Fe distances similar to the previous explanation on other R-Fe intermetallics and that of other strongly positive interactions such as 8j-8j. (c) 2005 American Institute of Physics.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000230168300025&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Physics, AppliedSCI(E)EICPCI-S(ISTP)
R source code
No full textR code for improved inference of epidemic modelsThis repository is intended to support the manuscript:Estimation of the basic reproductive number and mean serial interval of a novel pathogen in a small, well-observed discrete population(by Kendra M Wu, Steven Riley)</p
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