• 제목/요약/키워드: Observation frequency

검색결과 926건 처리시간 0.026초

ACOUSTIC TIME DOMAIN CORRELATION TECHNIQUE (ATDCT) IN OCEAN WAVE AND CURRENT OBSERVATION

  • I.N. Dienkulov;E.J. Kim;S.W. Yoon;V.V. Frolov
    • 한국음향학회:학술대회논문집
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    • 한국음향학회 1993년도 학술논문발표회 논문집 제12권 1호
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    • pp.210-214
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    • 1993
  • There are two general techniques to observe particle movements in fluid. One is the acoustic time domain correlation technique and another is the frequency domain Doppler-shift techniques. Both techniques were reviewed and mentioned their some merits and demerits in ocean wave and current observation. Some possible application of acoustic time domain correlation technique in ocean wind wave measurement was discussed.

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Study on the Forest Observation in Kushiro Wetland by using Dual-Frequency and Fully Polarimetric Airborne SAR (Pi-SAR) Data

  • Nakamura Kazuki;Wakabayashi Hiroyuki;Shinsho Hisashi;Maeno Hideo;Uratsuka Seiho;Nadai Akitsugu;Umehara Toshihiko;Moriyama Toshifumi
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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    • pp.405-409
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    • 2004
  • We chose the Kushiro wetland in Hokkaido, Japan, as a test site to monitor wetland areas. Synthetic aperture radar (SAR) can carry out continuous observation in any weather conditions, and can therefore be used to observe high humidity areas such as wetlands. We applied multi-parameter SAR data (dual-frequency, multi-polarization, and multi-incidence angle) to monitoring the wetland forest. To find the optimum incidence angle and polarization for monitoring the wetland biomass, a simple backscattering model of wetland vegetation was developed and applied to estimate backscattering coefficients for different biomass and surface conditions.

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아동의 ADHD 진단 보조를 위한 기계 학습 기반의 뇌전도 분류 (Machine Learning-Based EEG Classification for Assisting the Diagnosis of ADHD in Children)

  • 김민기
    • 한국멀티미디어학회논문지
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    • 제24권10호
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    • pp.1336-1345
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    • 2021
  • Attention Deficit Hyperactivity Disorder (ADHD) is one of the most common neurological disorders in children. The diagnosis of ADHD in children is based on the interviews and observation reports of parents or teachers who have stayed with them. Since this approach cannot avoid long observation time and the bias of observers, another approach based on Electroencephalography(EEG) is emerging. The goal of this study is to develop an assistive tool for diagnosing ADHD by EEG classification. This study explores the frequency bands of EEG and extracts the implied features in them by using the proposed CNN. The CNN architecture has three Convolution-MaxPooling blocks and two fully connected layers. As a result of the experiment, the 30-60 Hz gamma band showed dominant characteristics in identifying EEG, and when other frequency bands were added to the gamma band, the EEG classification performance was improved. They also show that the proposed CNN is effective in detecting ADHD in children.

치위생 임상실습에 대한 실습기간별 관찰/수행실습의 정도와 만족도 분석 (A Study on length of Clinical Practice Observation/Performance of Dental and Hygiene the Degree of Satisfaction)

  • 노미경
    • 한국치위생학회지
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    • 제5권2호
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    • pp.185-199
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    • 2005
  • The purpose of this research is to suggest a new desirable direction to a positive educational program for dental hygeine students, through the analysis of the degrees of observation and performance practice and the student satisfaction. This researched 471 senior dental hygien students from 5 separate universities. SPSS 10.0 for Windows was used to transform the results data analysis into statistics. The students' degree of satisfaction and length of observational/performance practice level were measured. For statistical anlysis the Mean and Standard Deviation were computed and the t-test and ANNOVA were carried out. The significant level of these statistics was a=0.05. 1. 12 weeks practice is the highest in the satisfaction of observation practice was the highest in clinical settings, followed by 16 weeks practice, and 8 weeks practice. 2. 12 weeks practice is the highest in the satisfaction of performance practice, followed by 16 weeks practice, and 8 weeks practice. 3. 8 weeks practice is the highest in the satisfaction of performance practice, followed by 12 weeks practice, and 16 weeks practice. 4. According to the frequency of clinical practice and satisfaction 12 week program of observation/performance practice is the most desirable, followed by 16 weeks practice, and 8 weeks practice.

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제주도 북동부 연안에서 추동계 파랑특성과 JONSWAP 스펙트럼의 적용성 평가 (Evaluation of Wave Characteristics and JONSWAP Spectrum Model in the Northeastern Jeju Island on Fall and Winter)

  • 강동협;이병걸
    • 한국해양환경ㆍ에너지학회지
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    • 제17권2호
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    • pp.63-69
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    • 2014
  • 제주도 북동부 연안에서 추 동계에 관측된 파랑자료를 주파수 분석을 통해 파랑의 특성을 검토하였다. 그리고 최대파고를 산정하기 위해 1차 회귀식을 이용하여 유의파고와 최대파고를 비를 계산하였다. 또한, JONSWAP 스펙트럼을 계산하기 위해 계산 된 유의파고와 첨두주파수를 이용하여 관측해역에 맞는 ${\gamma}$값을 추정하였다. 그 결과, 유의파고의 경우 1 m이하의 파랑이 가장 높은 빈도를 가지고 발생하였으며, 1차 관측 시 평균 0.523 m로 관측이 되었고, 2차 관측 시 평균 0.423 m로 관측이 되었다. 그 중 가장 높은 유의파고는 9월 15일부터 9월 17일까지 발생된 태풍으로 인해 4.8 m로 관측되었다. 첨두주파수의 경우 0.12~0.15 Hz(주기는 약 6.67~8.33초)가 가장 높은 빈도로 나타났으며, 유의파고와 첨두 주파수를 이용하여 계산 된 ${\gamma}$값은 평균 2.72를 나타내고 있다. 또한 직선 회귀 식을 이용해 계산 된 유의파고와 최대파고의 비는 $1.635H_s$로 계산되었다.

공간사용자의 본능적 시선탐색활동에 나타난 주사경로 알고리즘 특성 (The feature of scanning path algorithm shown at natural visual search activities of space user)

  • 김종하;김주연
    • 감성과학
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    • 제17권2호
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    • pp.111-122
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    • 2014
  • 본 연구는 지하철 로비공간을 대상으로 한 주시실험을 통해 공간정보의 본능적 시선탐색과정에서 나타나는 주시특성에 나타난 주사경로 알고리즘을 분석하였다. 주시기간 구간별 분석에서 주시시간이 오래 경과할수록 주사유형 횟수가 증가하고 있었는데, 오래 주시할수록 주시단절이 많이 일어난 것으로 해석이 가능하며, 주시에 따른 피로나 활발한 탐색이 자연스러운 공간탐색과정에서 일어나는 과정에서 화상범위를 벗어나는 경우가 많았던 것으로 보인다. 또한 시간구간의 변화에 따른 주사유형의 변화를 추세선으로 살펴본 결과, "집중"은 시간구간의 증가와 함께 가파른 증가, "대각 수직"은 완만한 증가를 보이는 반면, "순환 혼합 수평"은 감소 경향을 보이고 있다. 공간을 주시한 피험자의 주시데이터에는 다양한 시각정보가 포함되어 있는데, "주의집중"에 나타난 주사유형을 분석한 결과, 이상과 같은 의미 있는 결론을 도출할 수 있었다. 이러한 주사유형의 증감특성은 시간의 경과에 따른 주사경향을 파악함에 있어 기초자료가 될 수 있다.

과학박물관 탐방활동에서 나타난 초등 과학 영재 학생들의 관찰 유형 분석 (Patterns of Observation Type of Elementary Science-gifted Students in Visit Activities of the Science Museum)

  • 김미모아;정진우;김형범
    • 한국콘텐츠학회논문지
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    • 제15권3호
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    • pp.57-67
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    • 2015
  • 이 연구의 목적은 초등 과학 영재 학생들을 대상으로 과학박물관 탐방학습을 실시하여 관찰의 유형을 분류하고 이를 분석하였다. 이를 위해 과학 영재 학생 10명을 선정하여 탐방학습이 진행되는 동안 일어나는 관찰을 언어로 표현하도록 하여 모든 관찰 내용과 대화를 녹음하였다. 그 결과는 다음과 같다. 인지적 측면에서는 응답의 빈도가 높았고 자신의 의견을 배제하고 전시물과 관련하여 질문하고 응답하는 빈도가 높았으며, 정의적 측면에서는 권유의 빈도수가 가장 많았다. 관찰의 유형을 분류하고 이를 분석한 결과에서는 단수의 관찰 대상 전체를 시간 독립적으로 관찰하는 빈도가 높고, 시각을 사용하여 조작을 하지 않고 정성적인 방법으로 관찰하는 빈도가 높았다. 따라서 질문을 통한 언어적 상호작용은 관찰의 빈도와 다양성에 긍정적인 영향을 주며, 과학박물관 탐방학습에서 과학 영재 학생들의 다양한 관찰을 유도하기 위해서는 프로젝트 학습과 같은 특정 전시관이나 전시물을 학생이 직접 선택하여 집중 탐구할 수 있는 시간이나 학습지를 마련하면 더 효과적인 관찰 학습이 이루어질 수 있을 것으로 보인다.

The Analysis of Verbal Interaction on the Process of Elementary Students' Hypothesis Generation Learning

  • Park, Hee-Young;Lee, Il-Sun;Byeon, Jung-Ho;Kim, Won-Jung;Kwon, Yong-Ju
    • 한국과학교육학회지
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    • 제32권8호
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    • pp.1269-1280
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    • 2012
  • The purpose of this study is to analyze the verbal interaction during elementary students' hypothesis generation learning. For this study, 32 6th graders were selected and were assorted into heterogeneous small-groups by achievement levels. The topics of hypothesis generation learning were developed by analyzing the current elementary school curriculum. Each group's verbal interactions were audio/video taped and transcribed. After coding the protocol and having student retrospective interview, types and frequency of verbal interaction were analyzed. The frequency of verbal interaction during observation was highest and that of questioning situation identification was lowest. Regarding to the quality of verbal interactions, low level interactions were significantly frequent during observation. On the other hand, hypothetical explicans generation revealed high frequency of high level interactions. The results revealed that elementary students can make high level verbal interactions through hypothesis generation learning.

연안복합어선의 크기 변화에 따른 어로작업 효율 분석 (Analysis of efficiency of fishing operation by the change in the size of coastal composite fishing boat)

  • 김민선;황보규;장호영
    • 수산해양기술연구
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    • 제56권2호
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    • pp.126-137
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    • 2020
  • This study collected and analyzed the fishing process of existing fishing boat and newly built fishing boat by using the video observation methods to understand the improvement of fishing operation efficiency and safety according to the scale change of coastal composite fishing boat. The fishing operation efficiency was calculated by analyzing the frequency of movement, the movement distance and the moving time per basket used in the fishing process to derive the improvement of the newly built fishing boat compared to the existing fishing boat. It was confirmed that the mean frequency of movements decreased to 13.9%, the average moving time decreased to 21.8%, the mean movement distance increased to 20.5% and the movement through the top of gunwale did not occur. Movement of frequency, increased and time according to the fishing operation were directly affected by the width of side passages and the presence or absence of walking obstruction such as bulwark stay, hatch coaming and fishing gears on deck. The results of this study are expected to be used as basic data for redesigning into a safe and efficient coastal composite fishing boat in the future.