• 한국초전도학회:학술대회논문집
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• 한국초전도학회 2001년도 High Temperature Superconductivity Vol.XI
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• pp.3-3
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• 2001

• ETRI Journal
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• 제28권3호
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• pp.386-388
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• 2006

Monolithic SiGe heterojunction bipolar transistor (HBT) variable gain amplifiers (VGAs) with a feedforward configuration have been newly developed for 5 GHz applications. Two types of the feedforward VGAs have been made: one using a coupled-emitter resistor and the other using an HBT-based current source. At 5.2 GHz, both of the VGAs achieve a dynamic gain-control range of 23 dB with a control-voltage range from 0.4 to 2.6 V. The gain-tuning sensitivity is 90 mV/dB. At $V_{CTRL}$= 2.4 V, the 1 dB compression output power, $P_{1-dB}$, and dc bias current are 0 dBm and 59 mA in a VGA with an emitter resistor and -1.8 dBm and 71mA in a VGA with a constant current source, respectively.

• 한국초전도ㆍ저온공학회논문지
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• 제17권2호
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• pp.1-17
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• 2015

$MgB_2$ thin films with superior superconducting properties are very promising for superconducting magnets, electronic devices and coated conductor electric power applications. A clear understanding of flux pinning mechanism in $MgB_2$ films could be a big aid in improving the performance of $MgB_2$ by the enhancement of $J_c$. The fabrication advancement and the understanding of flux pinning mechanism of $MgB_2$ thin and thick films fabricated by using hybrid physical-chemical vapor deposition (HPCVD) are reviewed. The distinct kind of $MgB_2$ films, such as single-crystal like $MgB_2$ thin films, $MgB_2$ epitaxial columnar thick films, and a-axis-oriented $MgB_2$ films are included for flux pinning mechanism investigation. Various attempts made by researchers to improve further the flux pinning property and $J_c$ performance by means of doping in $MgB_2$ thin films by using HPCVD are also summarized.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2015년도 춘계학술발표대회
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• pp.567-570
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• 2015

기업, 개인에 있어 현재 많은 사람들이 인터넷을 통해 많은 행위를 하고 있다. 이중에 특히나 많은 Needs와 수요가 일어나고 관심 받고 있는 것은 e-Marketplace 이며 이중 구매하는 비중이 상당히 큰 분야가 B2B 구매시스템이다. 이에 해당 관련 시스템을 변경요청의 특성과 WBS에 미치는 영향을 분석하고 이를 개선해야 하는 방법에 대해 사례 분석을 통해 연구하였다.

• 대한전자공학회논문지SD
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• 제40권9호
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• pp.685-691
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• 2003

본 논문에서는 고속 통신 시스템 응용을 위한 12b 100 MS/s CMOS D/A 변환기(DAC) 회로를 제안한다. 제안하는 DAC는 전력소모, 면적, 선형성 및 글리치 에너지 등을 고려하여, 상위 8b는 단위 전류셀 매트릭스 (unit current-cell matrix)로 나머지 하위 4b는 이진 전류열 (binary-weighted array)로 구성하였다. 제안하는 DAC는 동적 성능을 향상시키기 위해 새로운 구조의 스위치 구동 회로를 사용하였다. 시제품 DAC회로 레이아웃을 위해서는 캐스코드 전류원을 단위 전류셀 스위치 매트릭스와 분리하였으며, 제안하는 칩은 0.35 um single-poly quad-metal CMOS 공정을 사용하여 제작되었다. 측정된 시제품의 DNL 및 INL은 12b 해상도에서 각각 ±0.75 LSB와 ±1.73 LSB이내의 수준이며, 100 MS/s 동작 주파수와 10 MHz 입력 주파수에서 64 dB의 SFDR을 보여준다. 전력 소모는 3 V의 전원 전압에서 91 mW이며, 칩 전체 크기는 2.2 mm × 2.0 mm 이다.

• 대한수학회논문집
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• 제36권4호
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• pp.685-704
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• 2021

The purpose of this paper is to establish a very general Cameron-Storvick theorem involving the generalized analytic Feynman integral of functionals on the product function space C²_a,b[0, T]. The function space C_a,b[0, T] can be induced by the generalized Brownian motion process associated with continuous functions a and b. To do this we first introduce the class ${\mathcal{F}}^{a,b}_{A_1,A_2}$ of functionals on C²_a,b[0, T] which is a generalization of the Kallianpur and Bromley Fresnel class ${\mathcal{F}}_{A_1,A_2}$. We then proceed to establish a Cameron-Storvick theorem on the product function space C²_a,b[0, T]. Finally we use our Cameron-Storvick theorem to obtain several meaningful results and examples.

• Bulletin of the Korean Chemical Society
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• 제20권3호
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• pp.307-313
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• 1999

2,4-Di-(2'-vinyloxyethoxy)benzylidenemalononitrile (la), methyl 2,4-di-(2'-vinyloxyethoxy)benzylidenecyanoacetate (lb), 3,4-di-(2'-vinyloxyethoxy)benzylidene malononitrile (2a), methyl 3,4-di-(2'-vinyloxyethoxy)benzylidenecyanoacetate (2b), 2,5-di-(2'-vinyloxyethoxy)benzylidenemalononitrile (3a), methyl 2,5-di-(2'-vinyloxyethoxy)benzylidenecyanoacetate (3b), 2,3-di-(2'-vinyloxyethoxy)benzylidenemalononitrile (4a), and methyl 2,3-di-(2'-vinyloxyethoxy)benzylidenecyanoacetate (4b) were prepared by the condensation of 2,4-di-(2'-vinyloxyethoxy)benzaldehyde, 3,4-di-(2'-vinyloxyethoxy)benzaldehyde, 2,5-di-(2'-vinyloxyethoxy) benzaldehyde, and 2,3-di-(2'-vinyloxyethoxy)benzaldehyde with malononitrile or methyl cyanoacetate, respectively. Trifunctional divinyl ether monomers 1-4 were polymerized readily with boron trifluoride etherate as a cationic initiator to give optically transparent swelling poly(vinyl ethers) 5-8 havina oxybenzylidenemalononitrile and oxycyanocinnamate, which is presumably effective chromophore for second-order nonlinear optical applications. Polymers 5-8 were not soluble in common organic solvents such as acetone and DMSO due to crosslinking. Polymers 5-8 showed a thermal stability up to 300 ℃ in TGA thermograms, which is acceptable for electrooptic device applications.

• ETRI Journal
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• 제33권2호
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• pp.169-175
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• 2011

This paper presents a double-sharpened decimation filter based on the application of a Kaiser and Hamming sharpening technique for multistandard wireless systems. The proposed double-sharpened decimation filter uses a pre-droop compensator which improves the passband response of a conventional cascaded integrator-comb filter so that it provides an efficient sharpening performance at half-speed with comparison to conventional sharpened filters. In this paper, the passband droop characteristics with compensation provides -1.6 dB for 1.25 MHz, -1.4 dB for 2.5 MHz, -1.3 dB for 5 MHz, and -1.0 dB for 10 MHz bandwidths, respectively. These results demonstrate that the proposed double-sharpened decimation filter is suitable for multistandard wireless applications.

• 한국항행학회논문지
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• 제10권2호
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• pp.138-144
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• 2006

본 논문에서는 와이브로와 무선랜 응용을 위한 이중 모우드 FET 믹서를 단일 게이트의 두 개 pHEMT를 캐스코드(cascode)로 연결하여 이중게이트 FET 믹서 형태로 구현하였다. 설계된 이중게이트 믹서는 와이브로와 무선랜 응용에서 DC 전력소모를 최소화하기위해 가변적인 변환이득을 갖도록 최적화되었다. 설계 믹서의 LO-RF간 격리도 특성은 2.3GHz~2.5GHz에서 약 20dB이다. LO신호가 0dBm이고 RF신호가 -50dBm일 때 믹서는 15dB의 변환이득을 갖는다. 수신되는 RF신호가 -50dBm에서 -20dBm까지 증가할 때 변환이득은 15dB에서 -2dB까지 바이어스에 따라 감소하게 된다. 가변 변환이득은 몇 가지 장점이 있다. 즉 IF단에서 AGC의 넓은 동작영역의 부담을 줄일 수 있고, 또한 믹서의 DC전력소모를 약 90% 절약할 수 있다.

• 한국기술혁신학회:학술대회논문집
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• 한국기술혁신학회 2000년도 추계 학술대회(The 2000 Autumn Conference of korea Technology Inovation Society)(한국기술혁신학회)
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• pp.69-87
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• 2000

Models and Strategies for Network Operator's B2B Ecommerce The B2B ecommerce market is one of the fastest growing areas in the telecom industry. However network operators have been slow to enter the arena, Network operator have been held back by their general unsurety about the Internet business. Network operators'core business(the supply of connectivity and transport service) is becoming unprofitable. As a result they are looking to diversify into areas where margins are higher. B2B ecommerce offers them a major way to achieve this. It is possible to identify various business models for offering ecommerce services to end user, ranging from the provision of complete packaged applications to the implementation and management of customized ecommerce solution. In this study the three main approaches available to network operators are the traditional IT outsourcing model, the ASP model and the community builder model.