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지진관측소 배경잡음 수준의 일변화가 지진 관측 능력에 미치는 영향 (Effect of diurnal variation of background seismic noise level on earthquake detectability)

  • 신동훈;신진수
    • 한국지구물리탐사학회:학술대회논문집
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    • 한국지구물리탐사학회 2009년도 학술대회 초록집
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    • pp.54-59
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    • 2009
  • 지진 관측소의 지진 관측 능력은 관측소의 잡음 수준에 좌우되어 잡음 수준이 높은 관측소는 작은 규모의 지진 또는 원거리의 지진에 의한 약한 지반 진동을 감지하기 어렵다. 그러므로 지진관측망의 지진 관측 능력을 고려하기 위해서는 지진관측소의 분포뿐만 아니라 각 관측소의 잡음 수준을 고려해야 한다. 대부분의 국내 지진관측소는 1 Hz 이상의 주파수 대역에서 인간의 활동에 의한 영향을 받고 있으며, 이로 인해 주간과 야간의 잡음 수준 차이가 나타난다. 이러한 잡음 변화에 따른 지진 관측 능력의 차이와 분포를 살펴보기 위해 2005년부터 2007년까지 한국지질자원연구원과 기상청에서 운영하는 광대역 관측소 30개소의 잡음 분석 결과를 이용하였다. 각 관측소의 잡음 수준을 고려하였을 때 야간에는 규모 2.4 정도 이상의 지진이 내륙에서 발생한 것을 관측할 수 있는 반면, 주간에는 규모 2.6 정도의 지진 관측 능력을 보였다.

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Study on the Ability Level Test of Mathematics Application

  • Dan, Qi;Song, Naiqing;Zhang, Nan
    • 한국수학교육학회지시리즈D:수학교육연구
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    • 제11권4호
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    • pp.235-246
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    • 2007
  • The background and the existing problems in teaching of mathematics application were analyzed. Based on the mathematics knowledge which from the simple application, complicate application, and synthetically application to the mathematics modeling, the ability level test questions of mathematics application was worded out to help the teaching and learning in mathematics application.

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계층적 특징 결합 및 검증을 이용한 자연이미지에서의 장면 텍스트 추출 (Scene Text Extraction in Natural Images using Hierarchical Feature Combination and Verification)

  • 최영우;김길천;송영자;배경숙;조연희;노명철;이성환;변혜란
    • 한국정보과학회논문지:소프트웨어및응용
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    • 제31권4호
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    • pp.420-438
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    • 2004
  • 이미지에 인위적 또는 자연적으로 포함된 텍스트는 이미지의 내용을 함축적이고 구체적으로 표현하는 중요한 정의이다. 이러한 정보를 실시간에 추출하여 정확히 인식할 수 있다면 다양한 분야에서 활용될 수 있다. 본 논문에서는 자연이미지에 포함된 장면 텍스트를 추출하는 방법으로서 텍스트의 색 연속성, 자기 변화 및 색 변화와 같은 낮은 수준의 이미지 특징으로 텍스트 후보 영역을 찾고, 다해상도 (Multi-resolution) 웨이블릿(Wavelet) 변환을 이용하여 높은 수준의 텍스트 특징인 획의 구성 여부로 검증하는 계층적인 구조를 제안한다. 색 연속성 특징은 대부분의 텍스트는 동일한 색으로 구성된다는 특징을 이용하는 것이고, 밝기 변화 특징은 텍스트 영역은 주변과의 밝기 변화가 존재하며 에지 밀도가 높은 특징을 이용한다. 또한, 색 변화 특징은 텍스트 영역은 주변 배경과의 색 변화가 존재하며, 밝기 변화보다 민감한 색 분산 값으로 표현할 수 있다는 장점을 이용한다. 높은 수준의 텍스트 특징으로서 다해상도 웨이블릿 변환을 이용하여 텍스트 획의 방향성 정보를 추출하고, 추출된 정보를 SVM(Support Vector Machine) 분류기로 검증하여 최종 영역을 확정한다. 제안한 방법을 다양한 종류의 이미지에 적용한 결과 배경이 복잡해도 비교적 안정적으로 텍스트 영역을 추출하는 것을 확인할 수 있었다.

어머니의 배경변인에 따른 양육지식과 영아와 상호작용의 관계 (Relationship between Parenting Knowledge and Mother-Infant Interaction According to the Mother's Background)

  • 홍순옥;김성혜
    • 아동학회지
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    • 제29권6호
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    • pp.55-71
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    • 2008
  • This study investigated parenting knowledge, interactions between mother and infant, and relationship between mother's parenting knowledge and mother-infant interaction by mothers' demographic variables. Subjects were 311 mothers. Instruments were the Knowledge of Child Development Inventory (Larsen & Juhasz, 1986) and the Assessment Profile for Early Childhood programs (Abbott-Shim & Sibely, 1987). Data were analyzed by t-test and ANOVA. Results showed (1) differences about parenting knowledge by mothers' employment status, age and education level, (2) differences in mother-infant interaction by mothers' age and education level, (3) parenting knowledge about physical development correlated positively with positive interaction, linguistic modeling, and sensitive response knowledge about linguistic and cognitive development had a large effect on positive mother-infant interaction and linguistic modeling.

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Stable Model for Active Contour based Region Tracking using Level Set PDE

  • Lee, Suk-Ho
    • Journal of information and communication convergence engineering
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    • 제9권6호
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    • pp.666-670
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    • 2011
  • In this paper, we propose a stable active contour based tracking method which utilizes the bimodal segmentation technique to obtain a background color diminished image frame. The proposed method overcomes the drawback of the Mansouri model which is liable to fall into a local minimum state when colors appear in the background that are similar to the target colors. The Mansouri model has been a foundation for active contour based tracking methods, since it is derived from a probability based interpretation. By stabilizing the model with the proposed speed function, the proposed model opens the way to extend probability based active contour tracking for practical applications.

아동기 자녀의 환경에 대한 관심과 보전행동에 관한 연구 (The Childrnes' Concern and Behavior on the Environmental Preservation)

  • 이정우
    • 대한가정학회지
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    • 제36권5호
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    • pp.75-88
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    • 1998
  • The purpose of this study is to investigate (1) the level of childrens' concern and behavior on the environmental preservation, (2) the influential factors related to the two dependent variables above mentioned. The subjects were 286 childrens, in October, 1997, in kwangju. The data obtained were analyzed by Mean, Person's correlation, Stepwise Regression and Path Analysis. The major findings were as follows: 1) The general tendency of the childrens' concern and behavior on the environmental preservation was over the average level. 2) According to the background variables(ie: environment information contracting time, family cohesion and adaptability, biospheric orientation, egoistic orientation), the childrens' concern on the environment was significantly different. 3) According to (1) the background variables(ie: environment information contracting time, family cohesion and adaptability, concern on the environment, biospheric orientation), (2) intermediated variable(ie: concern on the environment), the childrnes' behavior on the environmental preservation was significantly different. 4) The indirect variable of the positive influence for childrnds' behavior on the environment, environment information contracting time. The indirect variable of the negative influence for childrens' the environmental behavior was egoistic orientation.

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A Modified Ramp Reset Waveform for High Contrast Ratio in AC PDPs

  • Kim, Jae-Sung;Yang, Jin-Ho;Ha, Chang-Hoon;Whang, Ki-Woong
    • Journal of Information Display
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    • 제3권4호
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    • pp.13-18
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    • 2002
  • In general, the background light that is produced during the reset period deteriorates the dark room contrast ratio in AC PDP. In this paper, we propose a modified ramp reset pulse that can reduce the background light to an imperceptible level. In the new reset waveform, the discharges between the scan and sustain electrodes are minimized by applying a positive bias voltage to the sustain electrode and only the weak discharges between the scan and address electrodes are found to occur during the reset period. We also adopted the MgO coated phosphor layer to improve the address voltage margin that was reduced when the bias voltage in the modified ramp reset waveform was applied. As a result, the address voltage margin of 45 V which is the same level of the conventional method was ortained and the dark room contrast ratio was improved up to 7500 : 1.

Barriers to English Communication at the Korean EFL Adult Level

  • Jung, Woo-Hyun;Oh, Hyun-Ju
    • 영어어문교육
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    • 제11권3호
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    • pp.1-23
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    • 2005
  • This paper is a qualitative and quantitative study. The main purpose of the paper is to diagnose what makes English communication difficult at the Korean EFL adult level. In order to obtain data, this study employed interviews and a questionnaire. We identified thirty three factors blocking pathways to oral communication. Qualitative analysis repeatedly revealed patterns such as lack of grammar, lack of vocabulary, lack of background knowledge, and peer pressure, but quantitative analysis yielded somewhat different results: lack of colloquial expressions, lack of vocabulary, lack of various topics, problems in the educational system, difficulty in using existing knowledge, and lack of grammar. Findings which were common to both qualitative and quantitative analyses suggest that lack of linguistic knowledge and lack of background knowledge are major barriers learners encounter in communication. On the basis of the results, suggestions are made for overcoming these barriers.

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발전용 증기밸브 누설량 평가에 관한 연구 (Study on Evaluation of the Leak Rate for Steam Valve in Power Plant)

  • 이상국;박종혁;유근배
    • 동력기계공학회지
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    • 제11권1호
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    • pp.45-50
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    • 2007
  • Acoustic emission technology is applied to diagnosis the internal leak and operating conditions of the major valves at nuclear power plants. The purpose of this study is to verify availability of the acoustic emission as in-situ diagnosis method. In this study, acoustic emission tests are performed when the pressurized high temperature steam flowed through gate valve(1st stage reheater valve) and glove valve(main steam dump valve) on the normal size of 4 and 8". The valve internal leak diagnosis system for practical field was designed. The acoustic emission method was applied to the valves at the site, and the background noise was measured for the abnormal plant condition. To improve the reliability, a judgment of leak on the system was used various factors which are AE parameters, trend analysis, signal level analysis and RMS(root mean square) analysis of acoustic signal emitted from the valve operating condition internal leak.

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보령 담수호 유역의 논토양 및 하천수질 특성 -비영농기간을 중심으로 (A Study on the Paddy Soil and Water Quality in Boryung Freshwater Reservoir Watershed-During the non-cropping season-)

  • 최진규;구자웅;손재권;한강완;조재영;김선주
    • 한국농공학회:학술대회논문집
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    • 한국농공학회 1999년도 Proceedings of the 1999 Annual Conference The Korean Society of Agricutural Engineers
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    • pp.651-656
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    • 1999
  • This study was carried out to investigate the paddy soil and water quality in Boryung freshwater reservoir watershed during the non-cropping season. Soil pH of the Boryung freshwater reservoir watershed were 5.39∼5.78. Total-N and P contents were high by the accumulation of chemical fertilizer partly. Heavy metal content of paddy soils were natural background level. Water pH of the Boryung freshwater reservoir watershed ranged from 6.82 to 8.64. Total-N content affected by a livestock wastes and sewage water were the higher than that of others and total-P content showed below 0.1mg/L. Nitrate nitrogen contents was very high according to the influence a livestock waste and sewage water partly. Heavy metal contents of wateers were natural background level.

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