767 research outputs found
Toward seamless networking in indoor environments in millimeter wave bands
No full textThis thesis investigates the possibility of applying the 60GHz band to the indoor networking environment at the systemand link control levels. The work presented in this thesis aims at developing novel systemconcepts for seamless and cost-effective broadband local area networks operating in the 60GHz band in particular andmillimeter-wave bands in general. Different from many efforts today targeting point-to-point cable replacement solutions, this thesis attempts to apply the 60 GHz band to a broader context, i.e., the local area network environment in which multiple users and multiple applications share the network resource simultaneously. The utilization of this millimeter wave band, however, leads to smaller radio cell coverage due to propagation losses and line-of-sight requirements. Indoor networks operating at this band will comprise a large number of pico-cells corresponding to that many of antenna stations. As a result, the cost of many antenna stations has become a major contributor for the total cost of the networks infrastructure. To reduce the systems cost, it is therefore crucial that the complexity of an antenna station is simplified.Radio over fiber (RoF) techniques can be employed to achieve this goal. Particularly, this thesis is based on a RoF technique called Optical Frequency Multiplication (OFM) that is able to generate pure millimeter wave carriers remotely. Instead of placing all the signal processing functions in antenna stations, it is now possible to concentrate those complex functions in a single processing block, i.e., the central station (CS). since the propagation of 60 GHz signals is highly obstructed by objects, it is generally difficult to obtain good signal coverage in the indoor environment. In this thesis, we propose the novel Extended Cell concept that is able to overcome the problem of insufficient signal coverage. In this solution, a number of adjacent radio cells are grouped into an extended cell. Furthermore, all the antenna stations in an extended cell are set to operate in the same radio channel. By controlling the cells to be included into an extended cell, overlap areas between extended cells can be created in transitional areas in the floor to ensure seamless handovers of ongoing connections. To optimize the performance of the system with regards to variable realtime traffic patterns, we propose an algorithm to dynamically form extended cells based on the actual traffic under each cell. The performance of twoMediumAccess Control protocols, i.e., IEEE 802.11 representing the distributed protocol family and IEEE 802.16 representing the centralized protocol one, when applied to the proposed RoF and extended cell based architecture is also discussed in this thesis. A major effect when an optical distribution system is inserted in a traditional wireless network is the additional propagation delay introduced by the fiber links. This additional propagation delay can exceed the timing boundary of the MAC protocols and eventually stop them from working. Another problem also arises when the utilization of the 60 GHz band is combined with the extended cell concept. Specifically, mobile stations in a room will be completely hidden to other stations in other rooms.We show that the throughput of both protocols degrades when the length of optical distribution network increases, but this degradation is not significant.With regards to the hidden terminal problem, the performance of distributed and carried sense based protocols is severely affected. Finally, this thesis concerns the issues of maintaining quality of services (QoS) when the MAC protocols are applied to the proposed network architecture. We have shown that the proposed architecture does not affect the service differentiation mechanisms of the MAC protocols. Moreover, in this architecture, since the central station has the full control of the network, QoS and mobility control algorithms can also be greatly simplified to improve the performance of the network.Electrical Engineering, Mathematics and Computer Scienc
The life and works of James Miller, 1704-1744, with particular reference to the satiric content of his poetry and plays.
No full textPhDJames Miller was born the son of a Dorset rector in 1704. He
was himself ordained, but acquired no benefice until just before his
early death, probably because of a scathing portrayal of the Bishop
of London in one of his verse satires. At Oxford he wrote a vivacious
comedy of humours, set in the University. Its production in 1730
began his dramatic career, at a time when the number of London
theatres had just doubled, and new dramatic forms were being invented.
In 1731 his poem Harlequin-Horace, a witty inversion of
the Ars Poetica, attacked pantomime and opera, but also painted a
lively portrait of the entire theatrical world, in the tradition of
the Dunciad.
After collaborating in a translation of Moliere's works Miller
wrote two plays based on this author. Of all his dramatic works
these were the most successful with his contemporaries, and were
followed by a modernisation of Much Ado, and a ballad-opera adapted
from an afterpiece by Jean-Baptiste Rousseau, and rendered highly
topical. Miller made similar use of a recent French comedy showing
a Red Indian's reactions to civilisation, a satiric "fable" by Walsh
and Voltaire's Mahomet. A large quantity of original material was
incorporated into most of these, and this is generally satirical in
nature. The Indian is made to voice almost egalitarian sentiments.
An afterpiece, "The Camp Visitants", satirised military inaction
in the war, and was apparently banned. The manuscripts of the six
plays produced after the Licensing Act bear the examiner's deletions,
and illustrate the nature of the censorship at this time.
Miller's greatest strength is probably his flexible, vigorously
colloquial dialogue. His political satire is mostly contained in
the poetry, which attacks Walpole's administration with increasing
vehemence through the seventeen-thirties, until its fall. In 1740
two poems that used Pope in symbolic contrast to Walpole caused a
sensation. In both poetry and plays Miller is also a social satirist,
who lays unusually strong emphasis on false taste and the deterioration
of culture
Tele-operated climbing and mobile service robots for remote inspection and maintenance in nuclear industry
No full textBactrothrips brevitubus Takahashi
No full textBactrothrips brevitubus Takahashi (Figs 31, 38– 39) Bactrothrips brevitubus Takahashi, 1935: 61. Meiothrips baishanzuensis Duan & Li, 1995: 211. Syn. n. Described originally from Japan, this species is recorded widely in South China based on details given by Okajima (2006), and Meiothrips baishanzuensis Duan & Li is here considered a synonym based on examination of the holotype. Individuals are variable in morphology; in particular, the tubercles on abdominal segment VI are long in large males but short in small males (Figs 38, 39). The COI results support the interpretation that this variation is intraspecific. The species is identified by the long postocellar setae (about 3–5 times as long as diameter of one postocellus, sometimes a little shorter than the longest mid-dorsal setae) and short epima (always shorter than one third of epim). Material examined. CHINA, holotype female of baishanzuensis, Zhejiang Prov. (Baishanzu Mountain), 20.vii. 1994, H. Wu, in B.S. Duan collection; Hubei Prov. (Xingshan County), 3 females 8 males, 11.ix. 1994, F.S. Li; Fujian Prov. (Meihua & Liangye Mountains), 7 females 7 males on dead tree leaves, 6–14.xi. 2008, H.H. Zhang; Guangxi Auto. Reg. (Daming Mountain & Huaping County), 35 females 12 males on dead hanging tree leaves, 27.v– 8.vi. 2011, L.H. Dang; Yunnan Prov. (Xishuangbanna District), 1 male, 16.iii. 1957, D.H. Liu; Yunnan Prov. (Menghai County, Nannuo Mountain), 3 females, 1.iii. 1957, F.J. Pu; Yunnan Prov. (Nangun River), 1 female on dead hanging tree leaves, 16.xi. 2009, J. Chen & X.N. Zhang; Hainan Prov. (Xinglong County), 10 females 4 males on dead tree leaves, 16.iv– 7.vi. 1963, B.L. Zhang; Hainan Prov. (Limu Mountain), 9 females 4 males on dead tree leaves, 15–26.iv. 2010, M.Y. Lin; Hainan Prov. (Ledong County, Jianfengling Mountain), 1 male on dead hanging tree leaves, 18.v. 2009, L.H. Dang & F.Q. Chen; Hainan Prov. (Ledong County), 1 female, 4.xii. 2009, L.N. Huang. Distribution. China (Hubei, Anhui, Fujian, Guangxi, Zhejiang, Guangdong, Yunnan, Hainan, Taiwan); Japan.Published as part of Dang, Lihong & Qiao, Gexia, 2012, The genus Bactrothrips in China (Thysanoptera: Idolothripinae): morphological and molecular data, and a key with two new species, pp. 47-61 in Zootaxa 3449 on page 50, DOI: 10.5281/zenodo.21451
Optimizing green space locations to reduce daytime and nighttime urban heat island effects in Phoenix, Arizona
No full textabstract: The urban heat island effect is especially significant in semi-arid climates, generating a myriad of problems for large urban areas. Green space can mitigate warming, providing cooling benefits important to reducing energy consumption and improving human health. The arrangement of green space to reap the full potential of cooling benefits is a challenge, especially considering the diurnal variations of urban heat island effects. Surprisingly, methods that support the strategic placement of green space in the context of urban heat island are lacking. Integrating geographic information systems, remote sensing, spatial statistics and spatial optimization, we developed a framework to identify the best locations and configuration of new green space with respect to cooling benefits. The developed multi-objective model is applied to evaluate the diurnal cooling trade-offs in Phoenix, Arizona. As a result of optimal green space placement, significant cooling potentials can be achieved. A reduction of land surface temperature of approximately 1–2 °C locally and 0.5 °C regionally can be achieved by the addition of new green space. 96% of potential day and night cooling benefits can be achieved through simultaneous consideration. The results also demonstrate that clustered green space enhances local cooling because of the agglomeration effect; whereas, dispersed patterns lead to greater overall regional cooling. The optimization based framework can effectively inform planning decisions with regard to green space allocation to best ameliorate excessive heat.Corresponding Author:
Yujia Zhang
Arizona State University
[email protected]
Sicily and the Sicilians
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Previous issue date: 1889Thesis (B.L.)--University of Illinois, 1889.Ms.Lacking title page; title and author information from table of contents at beginning of volume. IU-RBound with 11 other B.L. theses from UIUC, 1889. IU-
On the MAC protocols for Radio over Fiber indoor networks
No full textRadio over Fiber (RoF) techniques have been long recognized as the promising solution for indoor networking at millimeter-wave bands. We discuss the possible deployment scenarios of an RoF network for indoor environment. In this paper, we try to find the answer to the question as to which Medium Access Control (MAC) protocol is suitable for an RoF network. To substantiate our claims, performance analysis of two popular MAC protocols employing RoF - IEEE 802.11 representing the distributed control protocol family and ETSI HiperLAN/2 representing the centralized family - is presented. We show that RoF techniques can be applied to both protocols. We also show that the centralized control protocol is an appropriate candidate for RoF networks. This study is expected to contribute to the speedy deployment of RoF for indoor network deployment.TelecommunicationsElectrical Engineering, Mathematics and Computer Scienc
Onderzoek naar de bruikbaarheid van het hoogtevliegtuig voor verkeersdoeleinden
No full textMechanical, Maritime and Materials Engineerin
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