• Title/Summary/Keyword: 다중시기 접근

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Multi-temporal NDVI Change Patterns and Global Land Cover Dynamics (다중시기 NDVI 변화 패턴과 토지 피복상태의 변화에 관한 연구)

  • Seong, Jeong-Chang
    • Journal of the Korean Association of Geographic Information Studies
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    • v.3 no.3
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    • pp.20-30
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    • 2000
  • Average annual NDVI values from the NOAA/NASA Pathfinder AVHRR Land Data Sets from 1982 to 1994 showed comprehensive systematic displacement patterns in Asia. Inter-annual growing season data, however, did not show such systematic patterns. The most likely cause for the abrupt displacements, which appear especially in 1982, 1989 and 1990, may be changes in satellite sensors, although global warming, El Ni$\tilde{n}$o-Southern Oscillation events, changes in processing algorithms, and changes in land-use patterns in various parts of Asia may also play some role. The results suggest that researchers must be extremely careful in their inter-annual global change research, since direct use of the raw data could cause unexpected results. Growing-season NDVI shows decreases throughout most of Southeast Asia and modest gains in northern China and some parts in India, which could be related to land-use and land-cover changes.

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Crop Classification for Inaccessible Areas using Semi-Supervised Learning and Spatial Similarity - A Case Study in the Daehongdan Region, North Korea - (준감독 학습과 공간 유사성을 이용한 비접근 지역의 작물 분류 - 북한 대홍단 지역 사례 연구 -)

  • Kwak, Geun-Ho;Park, No-Wook;Lee, Kyung-Do;Choi, Ki-Young
    • Korean Journal of Remote Sensing
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    • v.33 no.5_2
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    • pp.689-698
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    • 2017
  • In this paper, a new classification method based on the combination of semi-supervised learning with spatial similarity of adjacent pixels is presented for crop classification in inaccessible areas. Iterative classification based on semi-supervised learning is applied to extract reliable training data from both the initial classification result with a small number of training data, and classification results of adjacent pixels are also considered to extract new training pixels with less uncertainty. To evaluate the applicability of the proposed method, a case study of the classification of field crops was carried out using multi-temporal Landsat-8 OLI acquired in the Daehongdan region, North Korea. From a case study, the misclassification of crops and forests, and isolated pixels in the initial classification result were greatly reduced by applying the proposed semi-supervised learning method. In addition, the combination of classification results of adjacent pixels for the extraction of new training data led to the great reduction of both misclassification results and isolated pixels, compared to the initial classification and traditional semi-supervised learning results. Therefore, it is expected that the proposed method would be effectively applied to classify areas in which it is difficult to collect sufficient training data.

A Review of Change Detection Techniques using Multi-temporal Synthetic Aperture Radar Images (다중시기 위성 레이더 영상을 활용한 변화탐지 기술 리뷰)

  • Baek, Won-Kyung;Jung, Hyung-Sup
    • Korean Journal of Remote Sensing
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    • v.35 no.5_1
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    • pp.737-750
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    • 2019
  • Information of target changes in inaccessible areas is very important in terms of national security. Fast and accurate change detection of targets is very important to respond quickly. Spaceborne synthetic aperture radar can acquire images with high accuracy regardless of weather conditions and solar altitude. With the recent increase in the number of SAR satellites, it is possible to acquire images with less than one day temporal resolution for the same area. This advantage greatly increases the availability of change detection for inaccessible areas. Commonly available information in satellite SAR is amplitude and phase information, and change detection techniques have been developed based on each technology. Those are amplitude Change Detection (ACD), Coherence Change Detection (CCD). Each algorithm differs in the preprocessing process for accurate automatic classification technique according to the difference of information characteristics and the final detection result of each algorithm. Therefore, by analyzing the academic research trends for ACD and CCD, each technologies can be complemented. The goal of this paper is identifying current issues of SAR change detection techniques by collecting research papers. This study would help to find the prerequisites for SAR change detection and use it to conduct periodic detection research on inaccessible areas.

NAVER Data Lab data-based Assessment of National Awareness Vulnerability of Past Floods over the Korean Peninsula (2011-2018) (NAVER DATA LAB 데이터 기반 과거 한반도 홍수에 대한 대중 인지도 취약성 평가 (2011-2018))

  • Eun Mi Lee;Young Uk Yu;Young hun Jeong;Jong Hun Kam
    • Proceedings of the Korea Water Resources Association Conference
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    • 2023.05a
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    • pp.59-59
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    • 2023
  • 기후변화로 인한 집중호우와 홍수는 하천의 범람, 내수침수 등을 일으킨다. 최근 발생한 2022년9월 태풍 '힌남노'는 포항시 10명의 인명 피해와 1조 7000억원의 재산 피해로 막대한 피해를 야기시켰다. 본 연구는 2011년부터 2018년까지 시군구 단위의 행정구역별 홍수 기간 강우량, 피해액, 홍수 지역의 인구 자료를 NAVER DATA LAB(2016년부터 자료 제공) '홍수' 검색량 데이터와 비교 분석하였다. 본 연구에서는 다량의 강우량 또는 높은 피해액이 발생한 시기에 홍수 검색량이 낮았던 지역을 홍수에 대한 대중 인지도가 취약한 지역으로 정의하였다. '홍수' 검색량과 강우량, 피해액, 홍수 지역 인구와의 상관관계를 분석한 결과, 강우량과 인구는 각각 0.86, 0.81의 높은 상관계수를 보인 반면, 피해액은 0.52로 상대적으로 낮은 상관관계를 보였다. 2016-2018년 특/광역시단위 분석 결과, 총 17번의 홍수 발생 중 '인천광역시'와 '세종특별시'에서 피해액 규모가 각각 2, 3순위로 높았던 반면 홍수 인지도는 각각 6, 11순위로 홍수 인지도가 취약한 지역으로 평가되었다. 도 단위 평가 시, 총 34번의 홍수 발생 중 '강원도'와 '경상북도'에서 피해액 규모 3순위, 강우량 10순위 일 때, 홍수 인지도는 27순위로 홍수 인지도가 취약한 지역으로 평가되었다. 다중 선형회귀 기법을 통해 2016년부터의 데이터를 기반으로 모델을 훈련하여 2016년 이전의 '홍수' 검색량 예측 자료를 재생산하였다. 2011-2015년 특/광역시 중심의 평가에서, 총 25번의 홍수 발생 중 부산광역시에서 피해액 규모가 1순위, 강우량이 2순위로 높았던 반면 홍수 인지도는 6순위로 홍수인지도가 취약한 지역으로 평가되었다. 도 단위 평가 시, 총 50번의 홍수 발생 중 '충청남도'와 '경기도'에서 피해액 규모가 3순위일 때 홍수 인지도가 7순위로 홍수 인지도가 취약한 지역으로 평가되었다. 본 연구는 물리·사회시스템의 빅데이터를 분석하여, 사회수문학적 접근 방식으로 홍수에 대한 사회적 취약성을 새롭게 제시하며 사회과학과 수자원 분야의 융합연구 필요성을 강조하였다.

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Analysis of Anti-Bias Education Activities in Early Childhood Education (유아교육분야에서의 반편견 교육활동 연구 분석)

  • Jeong, Yu-Ri;Kwon, Kyee-Yum
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.1
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    • pp.321-330
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    • 2018
  • This study aims to analyze anti-bias education activities for young children in Korea by reviewing related research. Focusing on the themes of biases and teaching medium/methods applied in the research, it tends to enhance general understanding about anti-bias education activities for young children. For this purpose, a total of 125 research papers published from 1995- 2017 dealing with anti-bias activities/programs for young children were analyzed. The results of this study were as follows: In terms of the period of research, almost half of the studies (53 studies) were conducted from 2000- 2004. Regarding the themes of biases covered in the education activities, single bias related activities included 64.8% of the total studies reviewed, and the main themes of bias included disability and gender. In studies that included multiple bias themes, more than half investigated from three to five different bias themes, including appearance, family, disability, gender, race, and culture. The most common teaching medium/method applied in activities was children's story, accounting for 60.8% of all activities. The following was utilizing inclusive environment, which was 14.4% of the activities. Based on these findings, this study would help systematize the contents of anti-bias education and develop diverse teaching-learning approaches.

A Convergence Approach to Exploring Factors Affecting Teacher Efficacy of Early Childhood Teachers (유아교사의 교사효능감 영향요인 탐색을 위한 융합적 접근)

  • Park, Hye Jung;Lee, Yeon Gyu;Kim, Mi Jin
    • Journal of the Korea Convergence Society
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    • v.11 no.11
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    • pp.451-459
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    • 2020
  • In this study, data were collected from currently employed early childhood teachers in order to explore the factors affecting the teacher efficacy of early childhood teachers and 202 data were analyzed. Frequency analysis, correlation analysis, and multiple regression analysis were performed on the subjects' general characteristics, empathy, resilience, and teacher efficacy. As a result of the study, factors influencing early childhood teachers' teacher efficacy were identified as educational experience, job achievement, empathy, and resilience, and the explanatory power of the variable was 57.2% (F=45.848, p<.001). In conclusion, the higher the resilience (β=.480), job achievement (β=.286), teaching experience (β=.197), and empathy (β=.141) of early childhood teachers the higher the teacher efficacy was. Therefore, the development and education of a curriculum that combines regular and non-regular education programs that can improve resilience, job achievement, and empathy from the period as pre-service teachers are required to improve teacher efficacy of early childhood teachers.

The Factors Affecting the Perceived Symptoms of Temporomandibular Disorders in Academic High School Students (일부 인문계 고등학생들의 측두하악장애 자각증상 관련 영향요인)

  • Ji, Min-Gyeong
    • Journal of Convergence for Information Technology
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    • v.11 no.10
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    • pp.215-222
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    • 2021
  • The purpose of this study was to analyze the factors affecting the awareness of temporomandibular disorders in high school students and to provide basic data for the development of easy-to-access program to help the management of temporomandibular disorders. For data collection, convenience sampling was performed among academic high school students in Daejeon and North Jeolla Province to complete a self-administered questionnaire from December 1 to 30, 2019. The statistical analysis was conducted by t-test, one-way ANOVA, and Pearson correlation. Stepwise multiple regression analysis was conducted. Oral parafunctional habits were positively correlated with trait anxiety and both of them were positively correlated with the perceived symptoms of temporomandibular disorders. The most influential factors on the awareness symptoms of temporomandibular disorders in high school students were oral parafunctional habits, health habits, and trait anxiety. It is necessary to make positive communication and intervention, which meets high school age, in coping well with anxiety and managing oral parafunctional habits and apply an oral health promotion program that involves socio-psychological efforts to prevent them.

Understanding sediment characteristics and developing empirical model for specific degradation in South Korean river (국내 하천 유사 특성 이해와 유사량 추정을 위한 경험적 모델 개발)

  • Woochul Kang
    • Proceedings of the Korea Water Resources Association Conference
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    • 2023.05a
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    • pp.133-133
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    • 2023
  • 풍화작용에 의해 생성된 유사는 자연 매체에 의해 이동하고 하천에 도달하기 이전이나 이후 퇴적되며, 해당 과정 중에서 하상변동, 홍수위 상승, 제방 안정성, 두부 침식, 생태환경 변화, 수질문제 등 다양한 침식과 퇴적 관련 문제들이 발생한다. 이러한 유사 문제의 해결과 지속적인 하천관리를 위해서는 유사의 생성, 이송, 그리고 퇴적 과정에 대한 충분한 이해와 정량적인 유사량을 파악하는 것이 필수적이다. 다양한 연구들을 통해서 유사량을 정량적으로 파악하기 위해 여러 종류의 모델과 공식들이 제안 되어져 왔다. 그 중 경험적 모델의 경우 실제로 관측된 값을 기반으로 하며, 복잡한 계산이나 요구하는 자료가 다른 종류의 모델들 보다 적어 쉽게 접근이 가능하다. 이러한 경험적 모델은 유사에 영향을 주는 인자를 규명하거나 특정 유역이나 지역에서 이송 및 퇴적 되는 유사의 출처와 특성을 규명하는 초기 단계에서 유용하게 이용된다. 국내 하천의 경우 여름에 강우가 집중되고 대부분의 국토가 산지로 이루어져있어 상류에서 침식이 주로 발생한다. 또한, 본류 및 하류 지역의 하천은 유사의 퇴적이 주로 일어나서 하천의 형태와 물길이 형성된 충적 하천 형태로 발전 되어있기 때문에 국내 하천에서는 전반적으로 국부적이며 다양한 형태의 유사 관련 문제가 발생한다. 국내 하천에서 발생하는 유사 관련 문제를 해결하기 위해 국내 하천의 유사량을 추정하는 다양한 경험적 모델들이 지속적으로 개발되어왔다. 하지만 과거에 개발된 모델들의 경우 계측 자료가 충분하지 않은 시기에 개발 되었으며, 현재에는 활용하기 불가능하다. 본 연구에서는 국내 하천의 비유사량을 예측하는 동시에 국내 하천의 유사 특성을 이해하기 위해 과거에 국내 하천을 대상으로 비유사량을 추정하기 위해 개발되었던 경험적 모델을 개선하였다. 본 연구를 통해 기존 경험 모델의 경우 주기적인 업데이트가 필요함을 확인하였으며, 개발된 모델의 경우 국내 하천 유사 관리를 위해 미래 유사량 예측하는 등 다양한 방면으로 활용 관리가 가능할 것으로 보인다.

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Analysis of Determinant Factors of Apartment Price Considering the Spatial Distribution and Housing Attributes (공간지리적 요인과 주거특성을 고려한 공동주택 가격결정 분석)

  • Moon, Tae-Heon;Jeong, Yoon-Young
    • Journal of the Korean Association of Geographic Information Studies
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    • v.11 no.1
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    • pp.68-79
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    • 2008
  • Because local cities are different from large cities, they need to reflect their own characteristics of housing market. Thus in order to obtain useful implications for the establishing sound housing market in Jinju City, this paper investigated the characteristics of spatial distribution and determinant factors that affect apartment price in Jinju City. GIS representation of the apartments showed that most of old and small apartments were built in 'land readjustment project' areas executed in 1970s. On the contrary, new and large scale apartment complexes were built quite recently and distributed in the western and southern parts of the city. Next, in order to examine the factors which affect apartment price, this paper subtracted firstly several variables from the related studies. However in order to avoid multi-colinearity, variables were summarized by means of factor analysis. Then, setting apartment price as a dependant variable, 12 hedonic price models were established with 33 independent variables. As results, building age, floor area, accessibility to university and hospital, accessibility to arterial road, and stair-type building were turned out to be significant. These results will be used in making the supply and allocation plan of urban facilities and housing. Finally as conclusions this paper emphasized the need of periodic analysis of local housing market and establishing detailed housing information systems.

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Impact of Perceived Environmental Cues on Festival Satisfaction and Behavior Intention - Focused on Gwangju Chungjang Festival in 2008 - (지각된 환경단서가 축제 만족과 행동의도에 미치는 영향 - 2008 광주충장축제를 중심으로 -)

  • An, Tai-Gi;Kim, Hee-Jin
    • The Journal of the Korea Contents Association
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    • v.9 no.9
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    • pp.380-392
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    • 2009
  • This study aims to understand what aspects among perceived environmental cues affect on satisfaction and behavior intention of visitors with the object of Gwangju Chungjang Festival 2008, which is a city festival. The survey was performed in the festival period, from October 7 through, 12 2008 with 300 visitors who finished the touring of the Festival. All the 300 questionnaires were returned, but only 270 out of 300 were used, except for the unfaithful responses, for the analysis. For statistical process of the collected data, frequency analysis, reliability analysis, factor analysis and multiple regression were performed by using SPSS 12.0 for Windows via the process of data coding. As the result, first, the factor, environmental cues of city festival were shown differently in three dimensions of satisfaction. In other words, 'food factor' is an important factor for festival satisfaction. Second, for re-visit intention, which is the consequence variable and behavior intention of satisfaction regarding the environmental cue factor, 'convenient facility factor' and 'accessibility and promotion factor' were significant and 'promotion and guidance factor' for the recommendation factor was significant. On the contrary, 'food factor' did not have significant impact. Third and finally, as the analysis result of impact of festival satisfaction on re-visit intention and recommendation intention, which are the behavior intentions, festival satisfaction was significant. This study aims suggestion of development strategies for Gwangju Chungjang Festival 2008. It is appropriate time for this study at the point of promoting city festivals. Also, suggestions in this study can help promotion of development direction.