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1.
Jaehoon Lee Seongha Kim Yonghoon Kim Yunje Oh Seongtaek Hwang Jichai Jeong 《Lightwave Technology, Journal of》2003,21(2):521-527
Optically preamplified receiver performance according to the vestigial sideband (VSB) filtering has been numerically investigated for 40-Gb/s optical signals modulated with nonreturn-to-zero, duobinary nonreturn-to-zero (NRZ), return-to-zero (RZ), carrier-suppressed RZ, and duobinary carrier-suppressed RZ formats. The VSB filtering enables the spectral widths of NRZ, duobinary NRZ, and RZ signals to be reduced without severe power penalties at the receiver. On the other hand, carrier-suppressed RZ and duobinary carrier-suppressed RZ signals have no large advantages over VSB filtering because of the characteristics of their signals. Our results suggest that RZ signals are the most suitable modulation format for VSB filtering, without considering the filter loss, because of the tolerance of the intersymbol interference and a large spectral width. However, duobinary NRZ signals are the most suitable modulation format for VSB filtering, considering the filter loss, because of their narrow spectral width. 相似文献
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Attacks by adult stages of the soft tick Argas (Argas) neghmei (Acari: Argasidae) on inhabitants of the High Andean plateau of Argentina are reported. This is the first local report of this species, which was previously found in the north of Chile. Taxonomic differences between A. (A.) neghmei and other neotropical and exotic species of the genus are underlined. The status of the knowledge about the Argentine argasid fauna is briefly described. 相似文献
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Yong Bae Park Keum Cheol Hwang Ikmo Park 《Microwave and Wireless Components Letters, IEEE》2008,18(3):152-154
A tapered coaxial tip in a parallel plate waveguide is investigated. A boundary-value problem of electromagnetic scattering from a tapered coaxial monopole is solved rigorously based on the Fourier transform, eigenfunction expansion, and mode matching. Scattering parameters are represented in a series and computed to understand the behavior of the scattering in terms of the coaxial tip geometry. 相似文献
6.
Yun‐Seok Cho Bheong‐Uk Lee Kye‐Heon Oh 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2008,83(9):1211-1217
BACKGROUND: Environmental contamination by nitroaromatic compounds such as 2,4,6‐trinitrotoluene (TNT), hexahydro‐1,3,5‐trinitro‐1,3,5‐s‐triazine (RDX), atrazine, and/or simazine (TRAS) generated as waste from military and agricultural activities is a serious worldwide problem. Microbiological treatment of these compounds is an attractive method because many explosives and herbicides are biodegradable and the process can be made cost‐effective. We explored the feasibility of using cultures of Pseudomonas putida HK‐6 for simultaneous degradation of TRAS with the aim of microbial application in wastewater treatment in bench‐scale bioreactors. RESULTS: Experiments were conducted to study the effects of supplemental carbons, nitrogens, and Tween‐80 on the degradation of Ps. putida HK‐6 in media containing TRAS as target substrate(s). The most effective TRAS degradation was shown in the presence of molasses. Addition of nitrogen sources produced a delayed effect for the target substrate(s). Tween‐80 enhanced the degradation of target substrate(s). Simultaneous degradation of these compounds proceeded to completion within the given period. CONCLUSIONS: Ps. putida HK‐6 was capable of growth with TRAS, and the effects of supplements on TRAS degradation and simultaneous TRAS degradation were evaluated in bench‐scale bioreactors. The results of this study have practical applications in the processes of industrial waste stream treatment where the disposal of TRAS may be problematic. Copyright © 2008 Society of Chemical Industry 相似文献
7.
Gang Chen Zhonghua Yang Chor Ping Low 《Industrial Informatics, IEEE Transactions on》2006,2(4):269-280
In this paper, we address agent coordination from a dynamic systems perspective and propose a dynamic coordination model, which is inspired by biological metabolic systems. A new coordination mechanism through dynamic local adjustment (CDLA) is presented, and coordination is achieved when every agent utilizes explicitly the global system dynamics and performs iteratively a dynamic local adjustment procedure. The CDLA mechanism is investigated in an example multiagent shop floor system. The results show that the example manufacturing process is well-coordinated and the coordination approach is practically applicable and effective 相似文献
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We propose a new service for digital mobile communication systems. The service enables two or more users to hold a secure conference. Two requirements must be considered: privacy and authentication. Privacy involves ensuring that an eavesdropper cannot intercept the conversations of the parties holding the conference. Authentication involves ensuring that service is not obtained fraudulently in order to avoid usage charges. We present two new conference key distribution schemes for digital mobile communication systems. In these schemes, a group of users can generate a common secret keg over a public channel so that they may hold a secure conference 相似文献