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991.
Jung Mi Oh Sang Geun Koo Donghan Lee Soo-Jin Park 《Lightwave Technology, Journal of》2008,26(1):144-149
A passive optical network (PON) architecture based on a hybrid wavelength-division multiplexing (WDM) and time-division multiplexing (TDM) PON system with a remotely pumped erbium-doped fiber amplifier (EDFA) is presented as an excellent candidate for use in a next-generation optical access network. The remotely pumped EDFA operates as a bidirectional amplifier and provides a 15-dB gain to both upstream signals and seed light sources, so the sensitivity of upstream transmission is greatly improved. An upstream transmission of 1.25 Gb/s with a low seed channel power of -14 dBm is made feasible over a total reach of 25 km for 32-WDM channels and 16-TDM splits by the use of the remotely pumped EDFA. This scheme has advantages that it uses a single transmission fiber for both down-and up-stream signals and that it reduces the Rayleigh scattering contribution. 相似文献
992.
Jun Hyuk Cheon Jung Ho Bae Jin Jang 《Electron Device Letters, IEEE》2008,29(3):235-237
In this letter, we have studied the inverted staggered thin-film transistor (TFT) using a spin-on-glass (SOG) gate insulator and a low-temperature polycrystalline silicon (poly-Si) by Ni-mediated crystallization of amorphous silicon. The p-channel poly-Si TFT exhibited a field-effect mobility of 48.2 cm2/V ldr s, a threshold voltage of -4.2 V, a gate-voltage swing of 1.2 V/dec, and a minimum off-current of < 4 times 10-13A/ mum at Vds = -0.1 V. Therefore, the gate planarization technology by SOG can be applicable to low-cost large-area poly-Si active-matrix displays. 相似文献
993.
Datta A. Bhunia S. Jung Hwan Choi Mukhopadhyay S. Roy K. 《Very Large Scale Integration (VLSI) Systems, IEEE Transactions on》2008,16(7):806-815
In this paper, a profit-aware design metric is proposed to consider the overall merit of a design in terms of power and performance. A statistical design methodology is then developed to improve the economic merit of a design considering frequency binning and product price profile. A low-complexity sensitivity-based gate sizing algorithm is developed to improve economic gain of a design over its initial yield-optimized design. Finally, we present an integrated design methodology for simultaneous sizing and bin boundary determination to enhance profit under an area constraint. Experiments on a set of ISCAS'85 benchmarks show in average 19% improvement in profit for simultaneous sizing and bin boundary determination, considering both leakage power dissipation and delay bounds compared to a design initially optimized for 90% yield at iso-area in 70-nm bulk CMOS technology. 相似文献
994.
In this paper, we propose a fast‐convergent fairness scheme in IEEE 802.17 resilient packet ring (RPR) networks. In the proposed scheme, each station could rapidly approach fair rate by estimating the number of unbounded flows at each link. In addition, the fast‐convergent scheme could prevent rate oscillations in the RPR aggressive mode scheme under unbalanced traffic. The estimation mechanism is simple and scalable since it is stateless without per‐flow management. Through analytical and simulation evaluations our scheme was found to be stable and speedy when compared with 802.17 RPR fairness scheme or the proposed distributed virtual‐time scheduling in rings scheme. Our scheme could allocate bandwidth fairly and smoothly among flows and achieve high utilization at the same time in the RPR network. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
995.
Jong-Woong Kim Dae-Gon Kim Young-Chul Lee Seung-Boo Jung 《Components and Packaging Technologies, IEEE Transactions on》2008,31(1):65-73
Failure behaviors of anisotropic conductive film (ACF) and non-conductive film (NCF) interconnects were investigated by measuring the connection resistance. The four-point probe method was used to measure the connection resistance of the adhesive joints constructed with Au bump on Si chip and Cu pad on flexible printed circuit. The interconnection reliability was evaluated by multiple reflow process. The connection resistance of the ACF joints was markedly higher than that of NCF joints, mainly due to the constriction of the current flow and the intrinsic resistance of the conductive particles in ACF joints. The connection resistances of both interconnections decreased with increasing bonding force, and subsequently converged to about 10 and 1 mOmega at a bonding force of 70 and 80 N, for the ACF and NCF joints, respectively. During the reflow process, two different conduction behaviors were observed: increased connection resistance and the termination of Ohmic behavior. The former was due to the decreased contact area caused by z-directional swelling of the adhesives, whereas the latter was caused by either contact opening in the adhesive joints or interface cracking. 相似文献
996.
Fluorometric analysis of borohydride (BH4–) species by the reduction of arylaldehydes to the corresponding arylmethanols was investigated. 9-Anthracenecarboxaldehyde (9-AA) exhibited pronounced ratiometric fluorescence signaling behavior toward borohydride in alkaline aqueous media. The borohydride-selective signaling of 9-AA was unaffected by the presence of commonly encountered metal ions and anions. 1-Pyrenecarboxaldehyde (1-PA) also showed comparable borohydride signaling behavior. The detection limit was found to be 7.4?μM (0.11?ppm) for 9-AA and 15.7?μM (0.23?ppm) for 1-PA. The utility of the probe with μPAD as a convenient tool for the determination of borohydrides was demonstrated. 相似文献
997.
A Brønsted acid-catalyzed asymmetric Friedel–Crafts alkylation of 3-indolylsulfamidates with indoles has been established toward the efficient synthesis of biologically important bisindolylarylmethane derivatives containing the phenylsulfamate group. The reaction using chiral BINOL-derived phosphoric acid as the catalyst was tolerant to a diverse range of 3-indolylsulfamates and indoles, and provided for the first time bisindolylarylmethane sulfamate derivatives in good yields and with moderate to high enantioselectivities (up to 89% yield, 94:6 er). Moreover, some of these novel compounds were evaluated for their biological activities and confirmed to show bioactivity for preventing peripheral nerve degeneration. 相似文献
998.
Beomsue Kim Masahiro Fukuda Jung‐Yeol Lee Dongdong Su Srikanta Sanu Aymeric Silvin Audrey T. T. Khoo Taejoon Kwon Xiao Liu Weijie Chi Xiaogang Liu Sejong Choi Diana S. Y. Wan Sung‐Jin Park Jin‐Soo Kim Florent Ginhoux H. Shawn Je Young‐Tae Chang 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(24):8056-8060
Microglia, the brain‐resident macrophage, are involved in brain development and contribute to the progression of neural disorders. Despite the importance of microglia, imaging of live microglia at a cellular resolution has been limited to transgenic mice. Efforts have therefore been dedicated to developing new methods for microglia detection and imaging. Using a thorough structure–activity relationships study, we developed CDr20, a high‐performance fluorogenic chemical probe that enables the visualization of microglia both in vitro and in vivo. Using a genome‐scale CRISPR‐Cas9 knockout screen, the UDP‐glucuronosyltransferase Ugt1a7c was identified as the target of CDr20. The glucuronidation of CDr20 by Ugt1a7c in microglia produces fluorescence. 相似文献
999.
Jae Hyun Kim Illan Kim Yeonghun Song Min Jung Kim Sanghee Kim 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(32):11134-11138
The total synthesis of (+)‐neooxazolomycin was achieved from the amino‐acid d ‐serine. The efficiency of this approach is derived from the use of principles of memory of chirality and dynamic kinetic resolution in the intramolecular aldol reaction of a serine derivative to build the densely functionalized lactam framework and to install three contiguous stereocenters. The key intermediate was readily elaborated to the target natural product. 相似文献
1000.
Liwen Zhang Chenyu Wu Kenward Jung Yun Hau Ng Cyrille Boyer 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(47):16967-16970
A peculiar radical polymerization reaction is presented in which oxygen serves as a cocatalyst, alongside triethylamine, to provide activation with light in the far‐red (690 nm, 3 mW cm?2) of the PET‐RAFT process in the presence of zinc(II) (2,3,7,8,12,13,17,18‐octaethyl‐5,10,15,20‐tetraphenylporphyrin) as photocatalyst. Apart from the ability to exert temporal control by switching the light on or off, this system possesses the exciting capability of inducing temporal control by removal or reintroduction of oxygen. Furthermore, this multicomponent catalytic system was typified by controlled polymerizations of various acrylate and acrylamide monomers, which all resulted in well‐defined polymers with low dispersity (<1.2). The process displayed excellent living characteristics that were demonstrated through chain extensions and a range of degrees of polymerization (200–1600). 相似文献