• 한국농공학회논문집
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• 제53권5호
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• pp.35-42
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• 2011

This study is to check the applicability of SWAT-APEX (Soil and Water Assessment Tool-Agricultural Policy / Environmental eXtender) model as combined watershed and field models by applying the APEX to paddies in a watershed (465.1 $km^2$) including Yedang reservoir. Firstly, the SWAT were calibrated with 3 years (2000~2002) daily streamflow and monthly water quality (T-N and T-P) data, and validated for another 3 years (2003~2005) data. The average Nash-Sutcliffe model efficiency (ME) of streamflow during validation was 0.73, and the coefficient of determination ($R^2$) of T-N and T-P were 0.77 and 0.73 respectively. Next, running the SWAT-APEX model with the SWAT calibrated parameters for paddies, the $R^2$ of T-N and T-P were 0.80 and 0.76 respectively. The results showed that SWAT-APEX model was more correctly predicted for T-N and T-P loads than SWAT model. The difference results between watershed and field models was predicted to have substantial impact on NPS loads, especially on T-N and T-P loads. Therefore, to improve negative NPS load simulations should be considered the model characteristics as simulating mechanism to properly select the NPS model for agricultural watershed.

• 응용통계연구
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• 제31권6호
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• pp.811-823
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• 2018

호텔링 $T^2$ 통계량에 근거한 다변량 관리도는 공정의 이상상태를 식별하는 통계적 공정관리의 강력한 도구 중 하나이다. 다수의 품질 특성치를 동시에 모니터링하는데 사용된다. $T^2$ 관리도를 통해 이상신호가 탐지된다는 것은 평균 벡터의 변화가 있다는 것을 의미하게 된다. 그러나, 이러한 다변량 통계량의 신호는 이상신호에 대한 원인을 식별하기 어렵게 한다. 이 논문에서는 $T^2$ 통계량을 서로 독립인 항으로 분해한 Mason, Young, Tracy (MYT) 분해에 기반한 원인 식별 방법들을 살펴본다. 또한, R 소프트웨어를 사용하여 사례분석을 하고, 모의실험을 통해 각 절차의 성능을 비교 평가해보고자 한다.

• ETRI Journal
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• 제34권3호
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• pp.454-457
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• 2012

A miniaturized planar digital video broadcasting terrestrial (DVB-T) antenna, which is composed of a patterned helical line, an open stub, and an impedance matching circuit on an FR4 (${\varepsilon}_r$=4.4) substrate for portable media player applications, is presented in this letter. The antenna has monopole-like, omni-directional radiation characteristics and a wide impedance bandwidth (VSWR<3) in the DVB-T band from 174 MHz to 230 MHz at the VHF band.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.210-211
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• 2009

In this study, we propose characteristics improvement methods according to via hole plating method for FBAR Duplexer with US PCS($T_x$:1850MHz~1910MHz, $R_x$:1930MHz~1990MHz) bandwidth which is used for wireless systems. Also, we designed and fabricated 3.8*3.8*1.8mm size microminiature FBAR Duplexer based on this proposal. First of all, in this study, we fabricated pentagon shape resonators by different size to make filter combination, and their quality factor(Q) are 687 with 6.6% of $k_{eff}^2$. Using this resonators, designed 3*2Type $T_x$ filter and 3*4Type $R_x$ filter. The transmission line, which works as phase shifter, is designed with $210{\mu}m$ in width and 18mm in length Stripline type. Inductor, which is used for matching component, is designed with width of $75{\mu}m$, a technically achievable minimum width. And adopted plating method of filling via hole with conductive epoxy for improved grounding and thermal conductivity. Using these configuration with all of the matching component values, we found Duplexer characteristics of -1.57dB ~ -1.73dB in insertion loss, -56dB in attenuation at 1850MHz~1910MHz of $T_x$ band. Also, found -2.71 dB ~ -3.23dB in insertion loss, -58dB in attenuation at 1930MHz~1990MHz of $R_x$ band.

• 한국전기전자재료학회논문지
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• 제23권5호
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• pp.388-396
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• 2010

In this study, we propose characteristics improvement methods according to via hole plating method for FBAR Duplexer with bandwidth($T_x4: 1850 MHz ~ 1910 MHz, $R_x$:1930 MHz ~ 1990 MHz) which is used for wireless systems. Also, we designed and fabricated $3.8{\times}3.8{\times}1.8mm$ size microminiature FBAR Duplexer based on this proposal. First of all, in this study, we fabricated pentagon shape resonators by different size to make filter combination, and their quality factor(Q) are 687 with 6.6% of ${k_{eff}}^2$. Using this resonators, we designed $3{\times}2$ Type $T_x$ filter and $3{\times}4$ Type $R_x$ filter. The transmission line, which works as phase shifter, is designed with 210 ${\mu}m$ in width and 18 mm in length Stripline type. Inductor, which is used for matching component, is designed with width of 75 ${\mu}m$, a technically achievable minimum width. And adopted plating method of filling via hole with conductive epoxy for improved grounding and thermal conductivity. Using these configuration with all of the matching component values, we found Duplexer characteristics of -1.57 dB ~ -1.73 dB in insertion loss, -56 dB in attenuation at 1850 MHz ~ 1910 MHz of $T_x$ band. Also, found -2.71 dB ~ -3.23 dB in insertion loss, -58 dB in attenuation at 1930 MHz ~ 1990 MHz of $R_x$ band.

• 대한수학교육학회지:학교수학
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• 제17권2호
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• pp.203-222
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• 2015

본 연구의 목적은 고등학교 통계 수업 시간에 발생하는 교사와 학생 사이의 수업담화의 특징을 알아보는 것이다. 이를 위하여 Mehan(1979a)의 이론을 바탕으로 교사와 학생 사이의 수업담화를 분석하였다. 먼저, 연구참여 수학교사의 전형적인 통계 수업담화에 해당하는 1차시를 선정하고 이를 수업의 구조, I-R-E 연속체, 수업의 사회적 참여 구조를 중심으로 분석하였다. 본 연구의 결과, 연구참여 교사의 통계 수업은 Mehan(1979a)의 기본적인 수업 3단계인 도입-전개-정리의 틀이 분명하게 나타나는 지식 전달 위주의 강의식 수업 방식을 따르고 있었다. I-R-E 연속체를 살펴본 결과, 교사가 질문하고 교사가 답을 이야기하는 $I_T-R_T$ 구조가 자주 나타났으며, 학생의 참여가 거의 없는 독백적 수업이었다. 본 연구 결과를 통해 교사는 학생들이 담화에 참여할 수 있는 통계적 맥락을 형성하여 담화 학습 공동체를 만들고 메타과정적 유도행위를 통한 논증적 담화를 유도해야 함을 알 수 있었다.

• STI Policy Review
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• 제4권2호
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• pp.1-18
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• 2013

As the value and role of intellectual property increases in our knowledge-based economy, countries around the world have exerted various efforts to secure, utilize, and protect their intellectual property. The present study diagnoses the level of IP infrastructure of major OECD countries and analyzes their characteristics and impact. According to the diagnosis, the US, Switzerland, and Germany form a leading group followed by the mid-level countries of Korea, Ireland, Australia, and France, with Spain and Italy in the bottom group. In contrast to Korea's competitiveness in S&T and R&D infrastructures, its competitiveness in IP infrastructure is lower than the OECD average. This is thought to be due to Korea's IP infrastructure being hastily formed under the influence of international pressures rather than having been gradually built up by internal needs. A TFP analysis of the impact of IP infrastructure on economic growth shows IP infrastructure positively influences economic growth. Though this analysis is limited due to inability to secure sufficient data and indicators, it is a useful guide for understanding the nature and key characteristics of IP infrastructure.

• Journal of Ship and Ocean Technology
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• 제7권1호
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• pp.29-35
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• 2003

Intensive experimental investigation has been conducted on the characteristics of model tank with intruded flow. The remaining flow inside tank contribute to the dynamic behavior and further closely related to the stability of vessel as well. To understand the importance of the trapped flow and its dynamic effects a series of systematic tests were conducted using a bench tester that could generate periodic roll motion and also complex motions of combined roll-heave-sway. To accommodate experimental conditions and to create three degree freedom of motions, a bench tester was fabricated and verified. Having similarities in terms of flow trapped inside tank, theoretical approaches for A.R.T. were applied to the study. The major parameters including roll angle, period and flow height were varied in the experiments to obtain the characteristics of model tank.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1371-1375
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• 2005

The paper has analyzed the influence of tire design variable on the tire Force and Moment (F&M) characteristics, especially by the belt angle, the Plysteer Residual Aligning Torque (PRAT) which is considered as one of the causing factors for the vehicle pull. To validate the tire FE model, the tire stiffness and the PRAT which can be derived from the simulation data have been compared with the experimental data of test machine. In addition to PRAT characteristic, the tire stiffness and cornering characteristics due to the belt angle have been investigated. The effects of drum's curvature on the PRAT have been also investigated using the tire FE model and the usefulness of the current drum type F&M test machine can be confirmed.

• 한국산학기술학회논문지
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• 제19권6호
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• pp.231-239
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• 2018

본 연구의 목적은 영유아와 어머니의 일반적 특성, 사회적 지지 그리고 모아상호작용이 모아애착에 미치는 영향을 분석하는 것이다. 본 연구는 서술적 조사연구로 자료수집기간은 2016년 3월 1일부터 9월 30일까지였다. 영유아기의 자녀가 있는 어머니 215명을 대상으로 자가 보고형 설문지를 이용하여 일반적 특성, 사회적 지지, 모아상호작용 그리고 애착에 대한 자료를 수집하였다. 수집된 자료는 SPSS 24.0 프로그램을 이용하여 기술통계, 집단간 평균비교, 상관관계 그리고 다중회귀분석으로 분석하였다. 연구결과 영유아의 특성 중 성별(t=3.200, p<.002), 연령(t=4.037, p<.001)과 기질(F=4.614, p<.011)에 따라, 어머니의 특성 중 연령(F=18.028, p<.001)과 학력(F=4.241, p<.016)에 따라 애착의 평균값이 통계적으로 유의한 차이가 있었다. 애착은 사회적 지지(r=.507, p<.001) 및 모아상호작용(r=.571, p<.001)과 통계적으로 유의한 양의 상관관계가 있었다. 애착에 영향을 미치는 요인은 모아상호작용(${\beta}=0.361$, p<.001), 사회적 지지(${\beta}=0.309$, p<.001), 연령(30세미만)(${\beta}=-0.370$, p<.001) 그리고 결혼 기간(10년 미만)(${\beta}=-0.179$, p<.033)이었다. 애착에 중요한 영향을 미치는 사회적 지지와 모아상호작용을 높일 수 있는 중재 프로그램 개발이 필요할 것으로 생각된다.