• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.430-432
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• 2005

Although color characteristics of IPS mode are much better than TN or VA mode, there still remains a room for improvement of the color characteristics of IPS mode compared with the conventional CRT. It has been generally as sumed that inherent color variation of IPS mode is entirely owing to dependence of the effective retardation on wavelength and role of optical axis of IPS mode has been little considered. In this study, we investigated the effects of driving voltages on the effective retardation and the effective optical axis by a computer simulation. The result shows that rotation of effective optical axis is dependent on wavelength and tends to be smaller for larger wavelength.

• Journal of the Korean earth science society
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• v.38 no.3
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• pp.173-181
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• 2017

The stability of the steady Rossby-Haurwitz wave (R-H wave) in the nondivergent barotropic model (NBM) on the sphere was investigated with the normal mode method. The linearized NBM equation with respect to the R-H wave was formulated into the eigenvalue-eigenvector problem consisting of the huge sparse matrix by expanding the variables with the spherical harmonic functions. It was shown that the definite threshold R-H wave amplitude for instability could be obtained by the normal mode method. It was revealed that some unstable modes were stationary, which tend to amplify without the time change of the spatial structure. The maximum growth rate of the most unstable mode turned out to be in almost linear proportion to the R-H wave amplitude. As a whole, the growth rate of the unstable mode was found to increase with the zonal- and total-wavenumber. The most unstable mode turned out to consist of more-than-one zonal wavenumber, and in some cases, the mode exhibited a discontinuity over the local domain of weak or vanishing flow. The normal mode method developed here could be readily extended to the basic state comprised of multiple zonalwavenumber components as far as the same total wavenumber is given.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.412-414
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• 2022

Global Navigation Satellite Systems (GNSSs)을 이용한 위치정보 서비스가 다양해짐에 따라, 전파 교란 및 기만에 대한 GNSSs의 취약성에 대한 우려도 점점 커지고 있다. 이에 미국, 러시아, 유럽 등 자체적으로 GNSS를 보유하고 운영하고 있는 국가조차도 GNSS의 취약성을 보완할 수 있는 부가적인 항법시스템을 개발하고 있다. 그 중 현재 운영 중인 Medium Frequency (MF) 주파수 대역의 신호를 이용하여 Differential GNSS (DGNSS) 정보를 전달하는 인프라를 활용하여 항법 신호를 송출하는 Ranging Mode (R-Mode) 시스템이 유럽과 한국을 중심으로 개발 중에 있다. 하지만 MF 주파수 대역의 신호는 일몰 이후에 전리층 일부가 소멸되면서 상위 전리층에서 신호가 반사되어 지표면에서 강한 세기로 수신되는 특성을 갖고 있다. 이런 특성은 지표를 통해 전파하는 원 신호를 수신하는 과정에 큰 오차요소로 작용할 수 있다. 본 논문에서는 현재 송출되고 있는 R-Mode 신호의 야간 특성을 분석하고자 한다. 현재 충주, 어청도 DGNSS 기준국에서 송출하고 있는 R-Mode 신호를 다양한 안테나 종류로 수신해보고, 항법 시스템의 정밀도 성능에 악영향을 줄 수 있는 특성에 대한 보완방법을 모색하였다.

• The Korean Nurse
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• v.33 no.3
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• pp.79-91
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• 1994

The purpose of this study was to identify the meaningful nursing diagnosis in maternity unit and to suggest formally the basal data to the nursing service with scientific approach. The subject for this paper were 64 patients who admitted to Chung Ang University Hospital, Located in Seoul, from Mar. 10, to July 21, 1993. The results were as follows: 1. The number of nursing diagnosis from 64 patients were 892 and average number of nursing diagnosis per patient was 13.9. 2. Applying the division of nursing diagnosis to Roy's Adaptation Model, determined nursing diagnosis from the 64 patients were 621 (69.6%) in physiological adaptation mode and (Comfort, altered r/t), (Injury, potential for r/t), (Infection, potential for r/t), (Bowel elimination, altered patterns r/t), (Breathing pattern, ineffective r/t), (Nutrition, altered r/t less than body requirement) in order, and 139 (15.6%) in role function mode, (Self care deficit r/t), (Knowledge deficit r/t), (Mobility, impaired physical r/t) in order, 122 (13.7%) in interdependence adaptation mode, (Anxiety r/t), (Family Process, altered r/t) in order, 10(1.1%) in self concept adaptation mode, (Powerlessness r/t), (Grieving, dysfunctional r/t) in order. 3. Nursing diagnosis in maternity unit by the medical diagnosis, the average hospital dates were 3.8 days in normal delivery and majority of used nursing diagnosis, (Comfort, altered r/t) 64.6%, (Self care deficit r/t) 13.6% in order, and the average hospital dates were 9.6 days in cesarean section delivery and majority of used nursing diagnosis, (Comfort, altered r/t) 51.6%, (Self care deficit r/t) 15.2%, (Infection, potential for r/t) 9.9%, (Injury, potential "for r/t) 8.1%, (Anxiety r/t) 5.0%, (Mobility, impaired physical r/t) 3.3% in order, and the average hospital dates were 15.8days in preterm labor and majority of used nursing diagnosis, (Comfort, altered r/ t), (Anxiety r/t), (Injury, potential for r/t) in order, and the average short-term hospital dates were 2.5days, long-term hospital dates were 11.5days in gynecologic diseases and majority of used nursing diagnosis, (Comfort, altered r/t). (Self care deficit r/t), (Injury, potential for r/t), (Infection, potential for r/t) in order.

• Journal of Korean Elementary Science Education
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• v.33 no.4
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• pp.724-735
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• 2014

The purpose of this study was to confirm correlation between elementary school students' VARK Learning styles test and Scientific Communication Skills through VARK questionnaire (version 7.3) for Youngers and Scientific Communication Skills Test. The subjects were 99 in 6th grade students of an elementary school located in Gyeonggi-do, Korea. The results of this study were as follows: 64% of the students had multiple learning styles, but only 36% of the students preferred a single mode of information presentation. Among students had a single mode preference, the aural ("A") was the highest unimodal preference. Among "V(visual)" mode, "A" mode, "R(read/write)" mode, and "K(kinesthetic)" mode, "A" mode was the commonest learning mode which students had. In Scientific Communication Skills Test, students' overall average was 26.19p [scientific explanation type (11.85p), scientific insistence type (14.34p)]. Girls' scores were higher than boys in scientific explanation type, but not in scientific insistence type. The scores by communication forms were Text (5.67p), Number (6.87p), Table (6.15p), and Picture (7.49p). Girls' scores were higher than boys in Text and Picture forms but not in Number and Table forms. In result of correlation analysis (Spearman's rho) between VARK Learning Styles and the types & forms of Scientific Communication Skills, there were common correlation in "Read/write (R) learning style-Scientific insistence type", "Read/write (R) learning style-Grounds of Scientific insistence", "Read/write (R) learning style-Description of Scientific explanation", and "R learning style-Text form".

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.2A
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• pp.147-154
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• 2009

Antenna grouping algorithm is hybrid of beamforming and spatial multiplexing. In antenna grouping system, we partition $N_t$ transmit antennas into $N_r$ groups and use beamforming in a group, spatial multiplexing between groups. We can transmit $N_r$ data streams in the $N_t{\times}N_r$ antenna grouping system. With antenna grouping, we can achieve diversity gain through beamforming, and high spectral efficiency through spatial multiplexing. But if channel is ill-conditioned or there are some correlations between antennas, the performance of antenna grouping is seriously degraded and in that case, beamforming is the best transmit strategy. By selecting the antenna grouping mode when channel is well-conditioned and by selecting the beamforming mode when channel is ill-conditioned, we can prevent serious fluctuation of BER performance caused by varying channel condition and achieve the best BER performance. In this paper, we investigate mode selection algorithm which can select antenna grouping mode or beamforming mode. we also propose a simple mode selection criterion.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2021.11a
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• pp.8-9
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• 2021

중파대역의 전파는 지표면을 따라 전파되는 지표파와 전리층에 반사되어 전파되는 공간파가 있다. 중파 R-Mode는 TOA추정을 통해 위치를 결정한다. 전리층에 반사되는 공간파를 수신할 경우 TOA 오차는 커질 수밖에 없다. 측위 정확도 향상을 위해 안테나 기반 중파 R-Mode의 수신성능을 향상하는

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.1049-1052
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• 2004

In general, contrary to the CRTs with impulsive emission, liquid crystal displays have motion artifacts such as blurring. ghost image, decrease of dynamic CR(contrast ratio), and stroboscopic motion due to hold type driving method. In this paper, to improve motion picture quality of LCDs. impulsive driving method of black data insertion was applied to the OCB mode which is well known for its fast LC response time and wide viewing angle properties. Subject evaluation was carried out with CRT, TN, SIPS(Super IPS). and impulsive driving OCB. Moving picture image quality near CRT was obtained in impulsive OCB driving mode

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2000.05a
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• pp.249-255
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• 2000

HRIV(Hybrid Rule-Interval Variation) method is presented to stabilize a class of nonlinear systems, where SMC(Sliding Mode Control) and ADC (ADaptive Control) schemes are incorporated to overcome the unstable characteristics of a conventional FLC(Fuzzy Logic Control). HRIV method consists of two modes: I-mode (Integral Sliding Mode PLC) and R-mode(RIV method). In I-mode, SMC is used to compensate for MAE(Minimum Approximation Error) caused by the heuristic characteristics of FLC. In R-mode, RIV method reduces interval lengths of rules as states converge to an equilibrium point, which makes the defined Lyapunov function candidate negative semi-definite without considering MAE, and the new uncertain parameters generated in R-mode are compensated by SMC. In RIV method, the overcontraction problem that the states are out of a rule-table can happen by the excessive reduction of rule intervals, which is solved with a dynamic modification of rule-intervals and a transition to I-mode. Especially, HRIV method has advantages to use the analytic upper bound of MAE and to reduce Its effect in the control input, compared with the previous researches. Finally, the proposed method is applied to stabilize a simple nonlinear system and a modified inverted pendulum system in simulation experiments.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2016.05a
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• pp.40-41
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• 2016

위성전파항법시스템은 이용의 편리성으로 인해 다양한 분야에서 측위, 항법 및 시각동기 정보를 획득하기 위한 목적으로 널리 활용되고 있다. 그러나 위성전파항법시스템은 낮은 신호전력특성 때문에 전파간섭에 매우 취약하다. 전파간섭으로 인한 위성전파항법시스템의 가용성 저하 사례가 빈번해짐에 따라 백업 시스템에 대한 필요성과 국제적 공조를 통한 백업 시스템 마련에 대한 기술 협력의 공감대가 높아지고 있다. R-Mode는 현재 해상에서 활용되고 있는 전파신호를 이용하여 거리측정을 하는 방법으로써 신규 전파항법 인프라 구축에 따른 큰 투자 없이 적은 비용으로 위성전파항법시스템의 백업 시스템을 구현한다는 장점을 갖는다. 본 논문에서는 R-Mode의 기술 현황과 국제 표준화 동향에 대해 살펴본다. 그리고 R-Mode를 국내에 적용하기 위해 고려해야 할 사항들을 설명한다.