• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.212-213
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• 2008

This paper describes the analysis of the device characteristics of the NPT type 1200V Insulated gate Bipolar Transistor. In case of NPT type IGBT devices, optimized n-epi layer thickness and concentration is important to obtain low on-state voltage and breakdown voltage characteristics. In this paper, we analyzed on-state and off-state characteristics of NPT type IGBT. Breakdown voltage of designed IGBT was higher than 1200V when we optimized Field Limiting Ring structures. And also, on-state voltage characteristics was shown less then 2.5V at 25A of drain current.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제53권6호
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• pp.300-304
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• 2004

We have proposed the junction termination design employing shallow trench filled with silicon dioxide and field limiting ring (FLR). We have designed trenches between P+ FLRs to decrease the junction termination radius without sacrificing the breakdown voltage characteristics. We have successfully fabricated and measured improved breakdown voltage characteristics of the Proposed device for 1200 V-class applications. The junction termination radius of the proposed device has decreased by 15%-21% compared with that of the conventional FLR at the identical breakdown voltage. The junction termination area of the proposed device has decreased by 37.5% compared with that of the conventional FLR. The breakdown voltage of the proposed device employing 7 trenches was 1156 V, which was 80% of the ideal parallel-plane .junction breakdown voltage.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 D
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• pp.2169-2171
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• 2001

The vacuum gauge control system has been designed and implemented using multi-serial communication controllers (MSCC) for the 2.5 Gev storage ring at the Pohang Accelerator Laboratory (PAL). There are 20 Balzers vacuum gauges and 17 Granville-Phillips vacuum gauges at the storage ring. A MSCC have two RS485 (max speed 460.8Kbps) field network port, 8 channel serial communication ports (max speed 460.8Kbps) connected to gauge controller for serial communication control. 12 MSCCs are connected to a personal computer (PC) through the RS485 field network. The PC can automatically control the MSCCs by sending set of commands through the network. The commands specify the duration of the MODBUS protocol. Upon receiving a command from a PC running under Windows2000 through the network, the MSCC communicate through the serial output ports to gauge controller. In this paper, we describe control structure and scheme of the vacuum gauge control system.

• Transactions on Electrical and Electronic Materials
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• 제17권4호
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• pp.222-226
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• 2016

This paper investigated the trench process, unified field limit ring, and other products for the development of a 500 V-level unified trench gate power MOSFET. The optimal base chemistry for the device was found to be SF₆. In SEM analysis, the step process of the trench gate and field limit ring showed outstanding process results. After finalizing device design, its electrical characteristics were compared and contrasted with those of a planar device. It was shown that, although both devices maintained a breakdown voltage of 500 V, the Vth and on-state voltage drop characteristics were better than those of the planar type.

• Journal of Astronomy and Space Sciences
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• 제40권2호
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• pp.89-90
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• 2023

• 한국통신학회논문지
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• 제25권5A호
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• pp.763-771
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• 2000

적외선 탐색기에 널리 사용되는 레티클 시스템은 시계(field of view ; FOV) 상에 존재하는 표적의 위치를 구하는 대표적인 방법이다. 본 논문에서는 동심원(concentric annular ring) 레티클 탐색기의 표적 추적 성능을 시뮬레이션할 수 있는 효과적인 툴이 제안된다. 동적인 시뮬레이션을 위해 대상 탐색기는 Matlab-Simulink 상에서 구성되었으며, 이는 탐색기 및 무기의 개발 등이 필수적이다. 시계상에 섬광탄 등의 대응능력이 존재하는 경우, 표적에 대한 정확한 추적은 매우 어렵게 된다. 본 연구에서는 이러한 대응능력의 영향을 줄이기 위해 입력 신호와 기준 신호와의 상관 관계를 이용하는 반대응 기법이 제안된다. 구성된 툴 상에서 제안된 방법이 기존 방법에 비해 보다 효과적인 표적 추적 결과를 보임을 확인하였다.

• 대한수학회지
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• 제54권2호
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• pp.417-426
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• 2017

We explicitly determine fundamental units and regulators of an infinite family of cyclic quartic function fields $L_h$ of unit rank 3 with a parameter h in a polynomial ring $\mathbb{F}_q[t]$, where $\mathbb{F}_q$ is the finite field of order q with characteristic not equal to 2. This result resolves the second part of Lehmer's project for the function field case.

• 충청수학회지
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• 제34권4호
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• pp.317-326
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• 2021

Let K be an imaginary quadratic field other than ℚ(${\sqrt{-1}}$) and ℚ(${\sqrt{-3}}$), and let 𝒪_K be its ring of integers. Let N be a positive integer such that N = 5 or N ≥ 7. In this paper, we generate the ray class field modulo N𝒪_K over K by using a single x-coordinate of an elliptic curve with complex multiplication by 𝒪_K.

• 대한수학회지
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• 제38권5호
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• pp.915-935
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• 2001

Let V be any valuation domain and let E be a subset of the quotient field K of V. We study the ring of integer-valued polynomials on E, that is, Int(E, V)={f$\in$K[X]｜f(E)⊆V}. We show that, if E is precompact, then Int(E, V) has many properties similar to those of the classical ring Int(Z).In particular, Int(E, V) is dense in the ring of continuous functions C(E, V); each finitely generated ideal of Int(E, V) may be generated by two elements; and finally, Int(E, V) is a Prufer domain.

• 대한수학회지
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• 제49권6호
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• pp.1197-1214
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• 2012

The classes of $G_C$ homological modules over commutative ring, where C is a semidualizing module, extend Holm and J${\varnothing}$gensen's notions of C-Gorenstein homological modules to the non-Noetherian setting and generalize the classical classes of homological modules and the classes of Gorenstein homological modules within this setting. On the other hand, transfer of homological properties along ring homomorphisms is already a classical field of study. Motivated by the ideas mentioned above, in this article we will investigate the transfer properties of C and $G_C$ homological dimension.