• The Journal of the Acoustical Society of Korea
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• v.21 no.2
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• pp.120-127
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• 2002

As a new type of a linear decorrelating receiver, the Pseudo-Decorrelator was presented for asynchronous code division multiple access systems by the author. In this paper, the concept of the Pseudo-Decorrelator is extended to derive a multiuser receiver for WCDMA uplink systems over a Rayleigh fading multipath channel. Starting with the analysis of the multiple access components of the decision statistics, a non-square cross-correlation matrix for each bit is obtained. This cross-correlation matrix is then inverted, and the inverted matrix is applied to the decision statistics obtained from a conventional receiver. This receiver is near-far resistant and outperforms conventional receivers even for the cases in which synchronization errors, such as time delay errors and phase errors exist.

• Journal of Korea Port Economic Association
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• v.33 no.4
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• pp.99-116
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• 2017

This paper analyzes the characteristics of change in economic indicators logistics business performance indicators in Japan over the past decade. We compare the differences in management performance of groups related to logistics business strategy. This is because we want to show that the logistics business strategy is reflected in the management performance. Research methods include correlation analysis, crossover analysis, and variance analysis. The main results are as follows. First, logistic companies' sales are highly correlated with economic indicators such as GDP, trade value, and stock price. Second, there is a correlation between the business sectors and the proportion of tangible assets. It is understood that different business strategies are appropriate for each industry and each period. Third, the effects of business strategy variables on business performance variables were significant. In particular, the interaction effect of three variables showed a difference in the effect on the yield. The results of this study provide a better understanding of how logistics companies achieve a high performance in the changing economic environment over the past decade.

• 한국정보통신설비학회:학술대회논문집
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• 2006.08a
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• pp.111-116
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• 2006

통신용 지하 관로 자재로는 주로 100mm관(PVC관, FC관)과 50mm관(FC관)이 사용되고 있으며, 이들 관자재의 품질은 관로 시공 품질 뿐 아니라 케이블 포설을 위한 선로 구성에 큰 영향을 미치고 있어, 관자재의 품질 확보는 매우 중요하다고 할 수 있다. 관자재의 품질 성능을 나타내는 방법으로는 편평시험(5% 및 100% 변형하중)과 충격시험 결과를 많이 사용하고 있으나, 관로 시공 현장에서 이러한 성능 시험을 한다는 것은 현실적으로 불가능하여, 대부분의 현장에서는 관자재의 두께나 무게와 같은 물성치 측정으로 품질관리를 하고 있다. 이에 본 논문에서는 관자재의 물성치와 품질 성능간 상호 관계를 분석한 후, 상관성이 높은 항목들을 도출함으로써, 관종 별의 관자재의 물성치와 품질 성능간에는 상관성이 매우 높은 인자들이 있다는 것을 규명하였으며, 이를 통하여 관자재의 물성치 만으로도 품질 성능을 객관적으로 판단할 수 있는 근거를 제시하였다. 이를 이용하여 관로 시공 현장에서 관자재 품질관리와 시공 품질 향상에 활용할 수 있도록 하였다.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.213-213
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• 2015

밭에서의 점적 관개를 이용한 노지 재배의 경우 적정 관개 계획 수립을 위해서는 작물 및 토양의 수분 정보에 대한 정확한 파악이 필요하다. 본 연구에서는 밭 토양을 GIS(Geographic Information System)를 통해 격자 형태로 분할하여 작물의 증발산량 및 토양의 수분함량을 모의할 수 있는 격자 기반 토양 물수지 모형을 개발하였다. 본 모형을 통해 작물의 소비수량 및 필요 수량을 파악함으로써 작부기간 중 필요한 관개수량을 제시하는 것이 가능하다. 고도화 기상자료로는 국가농림기상센터에서 운영 중인 고해상도 WRF(Weather Research and Forecasting) 모형에서 생산된 격자 형태의 복사, 온도, 바람, 강수 자료를 사용하였고 고도화 기상자료의 격자 해상도 별로 모의되는 작물 및 토양의 수분 정보 간 비교 및 분석을 실시하였다. 토양 물수지 모형에 입력되는 격자형태의 자료로는 기상, 토성 및 토지이용 자료가 있으며 기상자료의 경우 가로 및 세로의 크기가 각 270, 810, 2430m로 동일한 3가지 경우로 나누어 적용했으며 토성 및 토지이용 자료의 경우 기상 격자의 최소 크기에 맞춰 가로 및 세로의 크기가 각 270m인 격자로 분할하였다. 이와 같은 과정에 의한 모의 결과 각 격자별 작물 증발산량, 토양수분함량 및 관개수량의 일 연별 시계열 자료를 얻을 수 있으며 동시간대 격자별 수문인자 값을 산정하고 위치에 따른 공간적 상호 상관성을 분석하였다. 결과적으로, 고도화 기상자료의 격자 크기에 따른 밭 토양 물수지 분석 결과를 통해 고도화 기상 격자의 규모별 밭 토양 물수지 분석 효용성을 파악하고자 하였다. 더불어, 시험 지역(Test Bed) 선정을 통해 토양수분 및 증발산량을 실측하고 본 모형의 모의 결과와 비교함으로써 검정하는 것을 향후 연구 계획으로 한다.

• Korean Journal of Childcare and Education
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• v.10 no.4
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• pp.119-132
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• 2014

The purpose of this study is to see how young children's playfulness and ability to creatively problem solve can affect their behavior. young children's playfulness in creases with in creasing creativity and personality traits and behavioral problems decrease with increasing of playfulness. Young children's behavioral problems increase with increasing of creative personality traits. In addition, young children's playfulness and creative personality characteristics affect their behavioral problems. The impact on the behavioral problems with variables for playfulness and creative personality traits has a negative correlation with creative curiosity, a sense of humor and expression of fun. The cognitive and physical spontaneity of the playfulness are correlated positively to young children's behavioral problems.

• Journal of Korea Water Resources Association
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• v.47 no.6
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• pp.537-546
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• 2014

Surface image velocimetry was introduced as an efficient and sage alternative to conventional river flow measurement methods during floods. The conventional surface image velocimetry uses a pair of images to estimate velocity fields using cross-correlation analysis. This method is appropriate to analyzing images taken with a short time interval. It, however, has some drawbacks; it takes a while to analyze images for the verage velocity of long time intervals and is prone to include errors or uncertainties due to flow characteristics and/or image taking conditions. Methods using spatio-temporal images, called STIV, were developed to overcome the drawbacks of conventional surface image velocimetry. The grayscale-gradient tensor method, one of various STIVs, has shown to be effectively reducing the analysis time and is fairly insusceptible to any measurement noise. It, unfortunately, can only be applied to the main flow direction. This means that it can not measure any two-dimensional flow field, e.g. flow in the vicinity of river structures and flow around river bends. The present study aimed to develop a new method of analyzing spatio-temporal images in two-dimension using cross-correlation analysis. Unlike the conventional STIV, the developed method can be used to measure two-dimensional flow substantially. The method also has very high spatial resolution and reduces the analysis time. A verification test using artificial images with lid-driven cavity flow showed that the maximum error of the method is less than 10 % and the average error is less than 5 %. This means that the developed scheme seems to be fairly accurate, even for two-dimensional flow.

• Korean Journal of Childcare and Education
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• v.8 no.6
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• pp.301-322
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• 2012

The purpose of this study is to provide the basic data which can effectively improve young children's peer interaction behavior. For this purpose, this study examined the differences in the peer interactions of 4-year-old or 5-year-old children according to gender and age, and relationship among young children's temperament and emotion regulation, mother's emotional expressiveness, and teacher-child relationships, and then analyzed the relative influence of these variables on peer interaction behavior. The results are as follows. It appeared that boys' positive peer interaction is higher than girls'. Boys' negative peer interaction also is higher than girls'. In addition, the positive peer interaction of 5-year-old children is higher than that of 4-year-old children. As a result of examining the relative influence on peer interactions, children's emotion regulation ability is the most influential variable.

• Journal of Korean Tunnelling and Underground Space Association
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• v.23 no.6
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• pp.485-502
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• 2021

In order to evaluate the impact of ground subsidence and superstructures that are inevitably caused by tunnel excavation, a total of seven major influencing factors of surface subsidence and structural soundness reduction were set, and a Parameter Study using numerical analysis was conducted. Stability analysis was performed using scheme of Boscardin and Cording method and the maximum subsidence amount and the angular displacement, and correlation analysis was performed for each major influencing factor. In addition, it was applied that used the mutual behavior of the ground and the structure by parameter analysis in the site of the 𐩒𐩒𐩒 tunnel located in Hwaseong-si, Gyeonggi-do, and the applicability of the site was analyzed. As a result, the error was found to be 1.0%, and it could be used as a basic material for determining the appropriate tunnel route under various conditions when evaluating the stability of the structure according to tunnel excavating at the design stage.

• Korean Journal of Childcare and Education
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• v.9 no.2
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• pp.97-115
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• 2013

The present study examined the relationships between work related flow (i.e., absorption, work enjoyment, and intrinsic work motivation) and role conflict causes (i.e., teacher's belief, teaching and interaction with young children, comradeship, relationships with parents, workload, supervision, and social awareness of the job). A canonical correlation analysis was performed on the data from a sample of 154 childcare teachers. The results are as follows (1) there was a reciprocal-causal relationship between teachers' role conflict causes and their work-related flow; (2) canonical function 1 showed that absorption and work enjoyment are strongly associated to a teacher's belief and supervision of conflict causes; and (3) canonical function 2 showed that intrinsic motivation has a relatively strong relationship with workload and supervision of conflict causes. It can be concluded that it is important for childcare teachers to have sufficient job resources to promote their flow at work. Further research is needed for investigation of teacher's flow at various conditions of work.

• The Journal of Korean Society for School & Community Health Education
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• v.10 no.2
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• pp.55-68
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• 2009

연구목적: 본 연구는 미국 인디애나 주에 소재하는 중학교와 고등학교 학생들 사이의 methamphetamine, MDMA, GHB, and Rohypnol과 같은 약물사용 특성을 파악하고 청소년 약물사용과 관련된 성과 학교 환경에 대한 인지된 안전도 특성을 분석하였다. 연구방법: 본 분석에 사용된 데이터는 Indiana Prevention Resource Center (IPRC)에서 2007 년도에 수행한 음주, 흡연, 약물사용 설문조사(ATOD) 응답자료로서 인디애나 주에 거주하고 있는 6-12 학년 사이의 학생들을 편의추출하여 조사가 가능했던 158,632명의 응답을 얻었다. 연구결과: 로지스틱 회귀분석에서 조사한 4개 약물을 사용하는 학생들의 관심도는 교실에 있을 때, 복도에서 혼자 있을 때, 방과후 활동을 위해 학교에 남아있을 때 불안전하다고 느끼는 약물 미사용자보다 더 높은 경향을 보였다. GHB, MDMA, Rohypnol을 사용한다고 응답한 학생이 여자보다 남자에서 더 많았고 상관관계분석 결과, 메탐페타민을 비롯한 네 가지 약물 사용의 상호간 상관도가 모두 유의미하게 높았다.