• Title/Summary/Keyword: $PSL_2(R)$

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DISCRETE CONDITIONS FOR THE HOLONOMY GROUP OF A PAIR OF PANTS

  • Kim, Hong-Chan
    • Journal of the Korean Mathematical Society
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    • v.44 no.3
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    • pp.615-626
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    • 2007
  • A pair of pants $\sum(0,\;3)$ is a building block of oriented surfaces. The purpose of this paper is to determine the discrete conditions for the holonomy group $\pi$ of hyperbolic structure of a pair of pants. For this goal, we classify the relations between the locations of principal lines and entries of hyperbolic matrices in $\mathbf{PSL}(2,\;\mathbb{R})$. In the level of the matrix group $\mathbf{SL}(2,\;\mathbb{R})$, we will show that the signs of traces of hyperbolic elements playa very important role to determine the discreteness of holonomy group of a pair of pants.

CLASS FIELDS FROM THE FUNDAMENTAL THOMPSON SERIES OF LEVEL N = o(g)

  • CHOI So YOUNG;Koo JA KYUNG
    • Journal of the Korean Mathematical Society
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    • v.42 no.2
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    • pp.203-222
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    • 2005
  • Thompson series is a Hauptmodul for a genus zero group which lies between $\Gamma$o(N) and its normalizer in PSL2(R) ([1]). We construct explicit ring class fields over an imaginary quadratic field K from the Thompson series $T_g$($\alpha$) (Theorem 4), which would be an extension of [3], Theorem 3.7.5 (2) by using the Shimura theory and the standard results of complex multiplication. Also we construct various class fields over K, over a CM-field K (${\zeta}N + {\zeta}_N^{-1}$), and over a field K (${\zeta}N$). Furthermore, we find an explicit formula for the conjugates of Tg ($\alpha$) to calculate its minimal polynomial where $\alpha$ (${\in}{\eta}$) is the quotient of a basis of an integral ideal in K.

Cloning, Expression in Escherichia coli, and Enzymatic Properties of a Lipase from Pseudomonas sp. SW-3

  • An, Sun-Young;Kim, Sang-Wan;Park, Yong-Lark;Joo, Woo-Hong;Lee, Young-Choon
    • Journal of Microbiology
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    • v.41 no.2
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    • pp.95-101
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    • 2003
  • The lipase gene (lipA) and its activator gene (lipB) of Pseudomonas sp. SW-3 were cloned and sequenced. The lipB was found to be present immediately downstream of lipA. The deduced amino acid sequences of lipA and lipB showed a high level of homology to those of other lipases belonging to the family I.1 of bacterial lipases. When lipA was expressed in Escherichia coli using T7 promoter, an active lipase was produced in cells carrying both lipA and lipB, but not in cells harboring only lipA. Recombinant lipase (rPSL) overproduced in an insoluble form was solubilized in the presence of 8 M urea, purified in a urea-denatured form and refolded by removing urea in the presence of the Ca$\^$2+/ ion. rPLS had maximum activity at pH 8.0 and 50$^{\circ}C$, was stable at pHs from 7.0 to 9.0 and below 50$^{\circ}C$, and showed the highest activity toward the p-nitrophenyl ester of palmitate (Cl6).

Back to Faraway Upriver Territories: Forest Products, Decentralization, and Aoheng Dayak's Return Migrations, Indonesian Borneo, 1960-2020

  • Bernard Sellato
    • SUVANNABHUMI
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    • v.16 no.2
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    • pp.215-261
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    • 2024
  • In the 1960s, the Aoheng, a small tribal group with immense territories on the upper Mahakam River, began out-migrating to downstream settlements in search of better living conditions. A trickle of young men, then their families, and more sizable groups, they settled in various towns along the river. In Samarinda, the provincial capital, they came to form a community of several hundred. When the powerful forest product boom (c. 1990) for the P. R. China market opened up the hinterland to extractive ventures, many Aoheng returned home to protect their rich natural resources from forceful outsiders. After 1998, decentralization policies established scores of new provinces, regencies, and districts across the country. Soon, West-Kutai was created as the interior "Dayak" regency, upstream and autonomous from the Moslem-Malay coastal regions. Coal mining and oilpalm plantations massively intensified, while Sendawar, its capital, offered hundreds of civil-service jobs and business opportunities. In 2012, West-Kutai was split to create yet another regency, Upper-Mahakam, prompting robust Aoheng reflux/return moves toward its upstream capital, Ujoh-Bilang. Already open to wild-frontier-style inroads by outsiders, it will soon be flooded by industrial ventures. The Aoheng, bound to become a minority in their own district, are struggling to defer their inevitable final dissolution.

Four-Channel Differential CMOS Optical Transimpedance Amplifier Arrays for Panoramic Scan LADAR Systems (파노라믹 스캔 라이다 시스템용 4-채널 차동 CMOS 광트랜스 임피던스 증폭기 어레이)

  • Kim, Sang Gyun;Jung, Seung Hwan;Kim, Seung Hoon;Ying, Xiao;Choi, Hanbyul;Hong, Chaerin;Lee, Kyungmin;Eo, Yun Seong;Park, Sung Min
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.9
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    • pp.82-90
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    • 2014
  • In this paper, a couple of 4-channel differential transimpedance amplifier arrays are realized in a standard 0.18um CMOS technology for the applications of linear LADAR(laser detection and ranging) systems. Each array targets 1.25-Gb/s operations, where the current-mode chip consists of current-mirror input stage, a single-to-differential amplifier, and an output buffer. The input stage exploits the local feedback current-mirror configuration for low input resistance and low noise characteristics. Measurements demonstrate that each channel achieves $69-dB{\Omega}$ transimpedance gain, 2.2-GHz bandwidth, 21.5-pA/sqrt(Hz) average noise current spectral density (corresponding to the optical sensitivity of -20.5-dBm), and the 4-channel total power dissipation of 147.6-mW from a single 1.8-V supply. The measured eye-diagrams confirms wide and clear eye-openings for 1.25-Gb/s operations. Meanwhile, the voltage-mode chip consists of inverter input stage for low noise characteristics, a single-to-differential amplifier, and an output buffer. Test chips reveal that each channel achieves $73-dB{\Omega}$ transimpedance gain, 1.1-GHz bandwidth, 13.2-pA/sqrt(Hz) average noise current spectral density (corresponding to the optical sensitivity of -22.8-dBm), and the 4-channel total power dissipation of 138.4-mW from a single 1.8-V supply. The measured eye-diagrams confirms wide and clear eye-openings for 1.25-Gb/s operations.