• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.6
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• pp.17-24
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• 2004

This paper describes a novel bit line structure to minimize coupling noise induced by coupling capacitance between bit lines. In DRAMs coupling capacitance is inherently present bit lines. As in submicron process the bit line space gets narrower. bit line coupling capacitance increases and this increased coupling capacitance sharply raises cross-talk noise. In this paper using different layers of metal for adjacent bit lines has been tested to reduces cross-talk noise and a novel bit line structure capable of reducing capacitance is introduced and verified.

• Proceedings of the KIPE Conference
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• 2015.11a
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• pp.183-184
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• 2015

본 논문은 3상 인버터에 사용되는 전류제어기 모델링을 복소벡터를 이용하여 해석한다. 동기좌표계에서 다중 입 출력 구조로 구성되어 있는 제어기 모델링을 복소 벡터 표기를 이용하여 단일 입 출력 구조로 나타낼 수 있어 제어기 설계 및 해석이 간편하다는 장점이 있다. 동기좌표계에서 RL부하는 커플링 성분이 존재한다. 동기주파수 50Hz, 200Hz일 경우 일반적인 PI 전류제어기 특성을 확인했으며, 동기 주파수가 200Hz이며 커플링 성분인 L값이 ${\pm}30%$인 조건에서 디커플링 및 복소 벡터 전류제어기의 특성을 비교했다. 디커플링 제어기의 특성은 오버슈트가 발생하고 긴 정착시간이 걸리지만 복소 벡터 전류 제어기는 커플링 성분의 오차에 관계없이 안정적으로 제어 수행이 가능하다. 시스템의 파라미터의 불확실성에 대해 복소 벡터 전류제어기가 강인한 특성을 가진다.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.39 no.1
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• pp.49-57
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• 2002

Including RF Package inductance, substrate coupling through conductive silicon(Si)-substrate is modeled and quantitatively characterized. 2-port substrate coupling model is extended for the characterization of multi-port substrate coupling between digital circuit block and analog/RF circuit block. Furthermore, scalable parameter extraction model is developed. Multi-port substrate coupling can be investigated by linearly superposing a frequency-dependent 2-port substrate coupling model using scalable parameters. In addition, Substrate coupling including RF package inductance effect is quantitatively investigated. It is shown that package effect increases substrate coupling and shifts a characteristic frequencies(i.e., poles) to the higher frequency range. The proposed methodology can be efficiently used to the mixed-signal circuit performance verification.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.05a
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• pp.22-25
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• 2009

Development of a curvic-coupling was presented in this paper. The research covers design, structural analysis, hot-temperature-torsion-test, curvic-coupling applied proto-type turbine disk manufacturing, and assembly test of a curvic-coupling rotor system for the turbopump application. Curvic-coupling was designed based on the Gleason-standard-tooth shape. The load capability of the designed curvic coupling was validated by the structural analysis and hot-temperature-torsion-test. A proto-type turbine disk which had adopted designed curvic-coupling was manufactured, assembled and tested to reveal that shaft-disk assembly run-outs in axial and radial directions were much smaller than the design requirements. The development will be finalized after spin test of shaft-disk assembly in near future.

• Polymer(Korea)
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• v.24 no.6
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• pp.770-776
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• 2000

The effect of unreactive coupling agent on mechanical and thermal properties of talc-filled polypropylene (PP) composites was studied. Stearic and oleic acids were introduced as coupling agents, and tensile, flexural, and impact strength, thermal stability and melting transition temperature were measured and analyzed according to the types and concentration of coupling agents. Tensile and flexural strength were enhanced by introduction of coupling agent and the maximum effect was observed at the concentration of 3 wt% of coupling agent. Tensile and flexural strength of PP treated with oleic acid were higher than those of PP treated with stearic acid. but impact strength vice-versa. The reasons for these results were postulated by analyzing morphologies of talc-filled PP observed by SEM.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.3
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• pp.66-73
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• 2003

In this study, a methodology of synchronous control which can be applied to position synchronization of a two-axis rotating system is developed. Based on coupling structure, the synchronous control system is composed of disturbance observer, speed and synchronous controllers. The speed controller is designed to follows speed reference. The disturbance observer is designed to restrain synchronous error. In addition, the synchronous controller is designed for a viewpoint of accurate synchronization in lead compensation law. The effectiveness of the proposed method is verified through simulation.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.10
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• pp.2052-2059
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• 2002

In this study, a synchronous controller algorithm being applicable to two-axis position synchronzation is developed. Based on coupling structure, the synchronous control system is composed of speed and synchronous controllers. The speed controller is designed to follow a speed reference. In addition, the synchronous controller is designed from the viewpoint of accurate synchronization and robust stability in H$\infty$ synthesis. Finally, the effectiveness of the presented controller is demonstrated through extensive experiments.

• Proceedings of the KIEE Conference
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• 1999.11d
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• pp.1126-1127
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• 1999

연산자 분리 시영역 모델을 이용하여 광섬유 커플러 ADM(add-drop multiplexer)의 필터링 효과를 분석하였다. 이 모델은 방향성 결합기나 브래그 격자를 포함하는 소자의 해석에 유용하다. 본 논문에서는 비대칭 구조를 고려했으며 결합계수, 코어의 반경, 개구수, 굴절율 변조 등의 파라미터를 이용하여 최적의 필터링 효과를 얻기 위한 구조를 설계하였다.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.301-304
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• 2008

This paper presented an structural efficiency of steel coupling beam jointed single plate shear connections with seat and top angle. Parameters for the test specimens were are seat and top angle, reinforcing of concrete, embedded length, section loss. Steel coupling beam with angle showed excellent strength, stiffness, energy dissipation capacity. The specimen with no reinforcement around the embedded steel plate showed slightly low deformation capacity because of early failure in the precast concrete walls. However, the specimen with reinforcement around the embedded steel plate showed good deformation capacity. Deformation capacity was not decrease despite short embedded length. The specimen with section loss showed excellent deformation capacity. Because shear strength of steel coupling beam was lesser than of connections. These results showed that for workability and cost efficiency, the proposed system is promising for one of steel coupling beam.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.4
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• pp.635-650
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• 2017

Acoustic emission (AE) sensors have broadly used to monitor the damage of underground structures and tunnels. The reliability of measured signal is determined by the coupling condition of the AE sensors which are embedded in the target underground structure. To secure the reliability of health monitoring results, it is important to understand the characteristics of the coupling materials. In this study, laboratory tests were performed using portland cement, micro cement, and gypsum as coupling materials in order to verify the bleeding characteristics. The effective parameters for bleeding were determined to be water-cement ratio, material type, curing time, and injected volume of coupling materials. As a results of the experimental study, the bleeding rate increases with an increase in a water-cement ratio and an injected volume; for portland cement, water-cement ratio and injected volume effects are larger than the micro cement. However, curing time is not much effective for occurrence of the bleeding phenomenon. It is anticipated that this study may be useful for the selection of suitable coupling materials for installation of acoustic emission sensors.