• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2011년도 춘계학술대회
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• pp.43-46
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• 2011

A novel circuit structure of dual-band bandstop filters is proposed in this paper. This structure comprises two shunt-connected tri-section stepped impedance resonators with a transmission line in between. Theoretical analysis from the equivalent circuit and design procedures are described. We represented graphs for filter design from the derived synthesis equations by resonance condition of circuits. Notably, advantages of the proposed filter structure are compact size in design, wide range of realizable resonance frequency ratio, and more realizable impedances.

• Journal of Magnetics
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• 제16권4호
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• pp.328-331
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• 2011

Here, we describe a dual spin valve structure with distinct switching fields for two pinned layers. A device with this structure has a staircase of three distinct magnetoresistive states. The multiple resistance states are achieved by controlling the exchange coupling between two ferromagnetic pinned layers and two adjacent anti-ferromagnetic pinning layers. The maximum magnetoresistance ratio is 7.9% for the current-perpendicular-to-plane and 7.2% for the current-in-plane geometries, with intermediate magnetoresistance ratios of 3.9% and 3.3%, respectively. The requirements for using this exchange-biased stack as a three-state memory device are also discussed.

• 대한전자공학회논문지TC
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• 제41권2호
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• pp.53-58
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• 2004

본 논문에서는 부성저항을 갖는 발진부의 귀환 경로에 PIN 다이오드를 이용한 스위칭 회로를 추가하여 저 위상잡음 듀얼밴드 전압제어 발진기를 구현하였다. PIN 다이오드에 전원이 인가되지 않았을 때는 5㎓ 대역에서 발진이 일어나고, 인가되었을 때는 1.8㎓ 대역에서 발진이 일어난다. VCO의 위상잡음을 향상시키기 위하여 공진기에 PBG(Photonic Bandgap)구조를 접지 면에 적용하였다. 5.25㎓에서 출력 전력은 -9.17㏈m, 위상잡음은 -102㏈c/㎐이고, 1.8㎓에서 출력 전력은 -5.17㏈m, 위상잡음은 -101㏈c/㎐이다.

• Journal of Information Display
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• 제2권1호
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• pp.1-4
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• 2001

We propose a dual in-plane parallel electrode structure of a vertical configuration of a helix-deformed ferroelectric liquid crystal (HDFLC) mode for better brightness than a single in-plain electrode case. This structure provides high brightness in addition to the analog gray scale capability, fast response, and wide-viewing characteristics. In contrast to a conventional HDFLC in a planar geometry, smectic layers arrange themselves parallel to the substrates and thus extremely uniform alignment of molecules in a large area is naturally achieved in our new configuration.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제49권9호
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• pp.523-526
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• 2000

A dual gate trench emitter IGBT structure is proposed and studied numerically using the device simulator MEDICI. The on-state forward voltage drop latch-up current density turn-off time and breakdown voltage of the proposed structure are compared with those of the conventional DMOS-IGBT and trench gate IGBT structures. The proposed structure forms an additional channel and increases collector current level resulting in reduction of on -state forward voltage drop. In addition the trench emitter increases latch-up current density by 148% in comparison with that for the conventional DMOS-IGBT and by 83% compared with that for the trench gate IGBT without degradation in breakdown voltage when the half trench gate width(Tgw) and trench emitter depth(Ted) are fixed at $1.5\mum\; and\; 2\mum$, respectively

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제17권11호
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• pp.2903-2923
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• 2023

Knowledge recommendation is a type of recommendation system that recommends knowledge content to users in order to satisfy their needs. Although using graph neural networks to extract data features is an effective method for solving the recommendation problem, there is information loss when modeling real-world problems because an edge in a graph structure can only be associated with two nodes. Because one super-edge in the hypergraph structure can be connected with several nodes and the effectiveness of knowledge graph for knowledge expression, a dual-channel hypergraph convolutional neural network model (DCHC) based on hypergraph structure and knowledge graph is proposed. The model divides user data and knowledge data into user subhypergraph and knowledge subhypergraph, respectively, and extracts user data features by dual-channel hypergraph convolution and knowledge data features by combining with knowledge graph technology, and finally generates recommendation results based on the obtained user embedding and knowledge embedding. The performance of DCHC model is higher than the comparative model under AUC and F1 evaluation indicators, comparative experiments with the baseline also demonstrate the validity of DCHC model.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.173-173
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• 2000

This paper discusses a observer based discrete-time controller design and presents a modified control structure for dual-stage hard disk drive systems using piezoelectric microactuator(MA). In plant modeling, dynamic coupling between VCM and MA is not considered. Each controller is organized independently and designed using pole placement. Simulation result shows that 4th-order controller achieves about 3kHz servo bandwidth and 0.22msec of 2% settling time.

• Korean Journal of Mathematics
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• 제17권4호
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• pp.487-493
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• 2009

We study the group structure of the automorphism group of the ternary self-dual tetracode of length 4.

• 한국전자통신학회논문지
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• 제11권9호
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• pp.841-848
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• 2016

본 논문에서는 DGS(: Defected Ground Structure)을 적용하여 WLAN 시스템에 적용 가능한 모노폴 안테나를 설계, 제작 및 측정하였다. 제안된 안테나는 마이크로스트립 급전을 바탕으로 두 개의 선로와 DGS를 갖도록 설계하여 이중대역 특성을 갖도록 하였다. 상용 툴인 HFSS을 사용하여 $W_2$, $L_{10}$, $W_3$과 DGS 파라미터에 대한 시뮬레이션을 수행하여 최적화된 수치를 얻었다. 제안된 안테나는 $21.0{\times}36.0{\times}1.6mm^3$의 크기로 유전율 4.4인 FR-4 기판 위에 설계 및 제작되었다. 제작 결과, 제안된 안테나는 -10 dB 임피던스 대역폭을 기준으로 700 MHz (2.10~2.80 GHz) 그리고 1,780 MHz(5.02~6.80 GHz)의 대역폭을 얻었다. 또한, 제안된 안테나의 측정 이득과 방사패턴 특성이 요구되는 이중대역에서 제시되었다.

• 한국전기전자재료학회논문지
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• 제21권1호
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• pp.44-48
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• 2008

Hole mobility characteristics of two representative biaxially strained SiGe/Si structures with high Ge contents are studied, They are single channel ($Si/Si_{1-x}Ge_x/Si$ substrate) and dual channel ($Si/Si_{1-y}Ge_y/Si_{1-x}Ge_x/Si$ substrate), where the former consists of a relaxed SiGe buffer layer with 60 % Ge content and a tensile-strained Si layer on top, and for the latter, a compressively strained SiGe layer is inserted between two layers, Owing to the hole mobility performance between a relaxed SiGe film and a compressive-strained SiGe film in the single channel and the dual channel, the hole mobility behaviors of two structures with respect to the Si cap layer thickness shows the opposite trend, Hole mobility increases with thicker Si cap layer for single channel structure, whereas it decreases with thicker Si cap layer for dual channel. This hole mobility characteristics could be easily explained by a simple capacitance model.