• Title/Summary/Keyword: change point analysis

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The Analysis of Eulsukdo Shoreline Change Using Multi-temporal Aerial Photo And DSAS Program (다시기 항공사진과 DSAS 기법을 이용한 을숙도 해안선 변화 분석)

  • Lee, Jae One;Kim, Yong Suk;Park, Sung Bae;Park, Chi Young
    • Journal of Korean Society for Geospatial Information Science
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    • v.21 no.1
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    • pp.11-18
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    • 2013
  • Eulsukdo located in the Nakdong Estuary plays important role in ecosystem and coastal wetland. There have been various changes in Eulsukdo up to now. Recently, we expect a great change of the western part of shoreline in Eulsukdo due to the floodgate construction but there is few databases. In this study, shorelines were digitized after we had produced the ortho-images by using aerial photos taken for 30 years(8 times). SCE, NSM and EPR were analysed by DSAS 4.2 program using vector data. In addition, the changes of shoreline were analysed in October 2011 from before Eulsukdo water gate construction to now by adding field surveying with VRS. The amount of years shoreline change is -0.34m/yr in 2009(before water gate construction) and -0.50m/yr in 2011(during the water gate construction), and the change trend shows an accumulation aspect.

Development of an Instrument for Measuring Action Competence on Climate Change within High School Students (고등학생 기후변화 대응 실천역량 검사도구의 개발)

  • Baek, Seongheui;Shin, Hyeonjeong;Kim, Chan-Jong
    • Journal of The Korean Association For Science Education
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    • v.41 no.6
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    • pp.533-542
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    • 2021
  • This study aims to develop an instrument for measuring high school students' action competence on climate change (ACoCC). The instrument is defined as the construct comprised of seven factors and thirty-five items and takes approximately 15 minutes to fill out. A panel of experts and students' content validation were undertaken to modify the items. Five hundred and twenty-eight first and second graders in Korean high schools participated in the instrument survey. To assess the reliability and validity of ACoCC instrument, item analysis (mean, skewness, kurtosis, item-total correlation), internal consistency estimate, and confirmatory factor analysis were used. It was appropriate to use the 7-dimensional ACoCC instrument (knowledge about climate change, climate change sensibility, reflection, communication, integrated thinking, willingness, decision making), with 35 items for high school students. The following instrument was self-report given in the 5-point Likert scale (1=strongly disagree, 2=disagree, 3=neutral, 4=agree, 5=strongly agree). The internal consistency coefficient was shown as a whole was shown as 0.953, and the subscale's internal consistency coefficient ranged from 0.786 to 0.862.

Trend analysis of rainfall characteristics and its impact on stormwater runoff quality from urban and agricultural catchment

  • Salim, Imran;Paule-Mercado, Ma. Cristina;Sajjad, Raja Umer;Memon, Sheeraz Ahmed;Lee, Bum-Yeon;Sukhbaatar, Chinzorig;Lee, Chang-Hee
    • Membrane and Water Treatment
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    • v.10 no.1
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    • pp.45-55
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    • 2019
  • Climate change has significantly affected the rainfall characteristics which can influence the pollutant build-up and wash-off patterns from the catchment. Therefore, this study explored the influence of varying rainfall characteristics on urban and agricultural runoff pollutant export using statistical approaches. For this purpose, Mann-Kendall and Pettitt's test were applied to detect the trend and breakpoint in rainfall characteristics time series. In addition, double mass curve and correlation analysis were used to drive the relationship between rainfall-runoff and pollutant exports from both catchments. The results indicate a significant decreased in total rainfall and average rainfall intensity, while a significant increased trend for antecedents dry days and total storm duration over the study periods. The breakpoint was determined to be 2013 which shows remarkable trend shifts for total rainfall, average rainfall intensity and antecedents dry days except total duration. Double mass curve exhibited a straight line with significant rainfall-runoff relationship indicates a climate change effect on both sites. Overall, higher pollutant exports were observed at both sites during the baseline period as compared to change periods. In agricultural site, most of the pollutants exhibited significant (p< 0.05) association with total rainfall, average rainfall intensity and total storm duration. In contrast, pollutants from urban site significantly correlated with antecedent dry days and average rainfall intensity. Thus, total rainfall, average rainfall intensity and total duration were the significant factors for the agricultural catchment while, antecedents dry days and average rainfall intensity were key factors in build-up and wash-off from the urban catchment.

Experimental Study on the Thermal Characteristics According to the Content Change of Biodiesel Mixture (바이오디젤 혼합물의 함량변화에 따른 열적 특성에 대한 실험적인 연구)

  • Ju Suk Kim;Jae Sun Ko
    • Journal of the Society of Disaster Information
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    • v.19 no.3
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    • pp.532-544
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    • 2023
  • Purpose: To identify and evaluate the risk of chemical fire causative substances by using thermal analysis methods (DSC, TGA) for the hazards and physical property changes that occur when newly used biofuels are mixed with existing fuels It is to use it for identification and evaluation of the cause of fire by securing data related to the method and the hazards of the material according to it. Method: The research method used in this experiment is the differential scanning calorimeter (DSC: Difference in heat flux) through quantitative information on the caloric change from the location, shape, number, and area of peaks. flux) was measured, and the weight change caused by decomposition heat at a specific temperature was continuously measured by performing thermogravimetric analyzer (TGA: Thermo- gravimetric Analyzer). Result: First, in the heat flux graph, the boiling point of the material and the intrinsic characteristic value of the material or the energy required for decomposition can be checked. Second, as the content of biodiesel increased, many peaks were identified. Third, it was confirmed through analysis that substances with low expected boiling points were contained. Conclusion: It was shown that the physical risk of the material can be evaluated by using the risk of biodiesel, which is currently used as a new energy source, through various physical and chemical analysis techniques (DSC + TGA).In addition, it is expected that the comparison of differences between test methods and the accumulation and utilization of know-how on experiments in this study will be helpful in future studies on physical properties of hazardous materials and risk assessment of materials.

Measurement Accuracy for 3D Structure Shape Change using UAV Images Matching (UAV 영상정합을 통한 구조물 형상변화 측정 정확도 연구)

  • Kim, Min Chul;Yoon, Hyuk Jin;Chang, Hwi Jeong;Yoo, Jong Soo
    • Journal of Korean Society for Geospatial Information Science
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    • v.25 no.1
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    • pp.47-54
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    • 2017
  • Recently, there are many studies related aerial mapping project and 3 dimensional shape and model reconstruction using UAV(unmanned aerial vehicle) system and images. In this study, we create 3D reconstruction point data using image matching technology of the UAV overlap images, detect shape change of structure and perform accuracy assessment of area($m^2$) and volume($m^3$) value. First, we build the test structure model data and capturing its images of shape change Before and After. Second, for post-processing the Before dataset is convert the form of raster format image to ensure the compare with all 3D point clouds of the After dataset. The result shows high accuracy in the shape change of more than 30 centimeters, but less is still it becomes difficult to apply because of image matching technology has its own limits. But proposed methodology seems very useful to detect illegal any structures and the quantitative analysis of the structure's a certain amount of damage and management.

An Analysis of the Course Fulfillment Change in Fisheries Business Administration Curriculum with Business Education Accreditation (경영교육인증에 따른 수산경영학 교과과정 및 학업이수의 변화 분석과 과제)

  • Lee, Dong-Ho
    • The Journal of Fisheries Business Administration
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    • v.45 no.2
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    • pp.39-59
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    • 2014
  • Recently the rapid changes of the social environment make both university and every each department should have to renovate and adjust all of the educational components. The most dominant and issuable change of business administration education is the Business Education Accreditation which was certified by the KABEA(Korean Association of Business Education Accreditation). And the only two department of fisheries business administration which in Gyeongsang National University and Pukyong National University has been accredited recently. Though The department of fisheries business administration in Korea has been influenced by that Accreditation, there is few research and analysis on educational change. So it is very important that research on the curricular constitution and change of the curriculum for considering the its own effect and influence. This paper aims to explore the curricular constitution, change and course fulfillment of fisheries business administration after the business education accreditation based on the case of the department of fisheries business administration in Gyeongsang National University. The analysis of fisheries business administration change will help develop sustainable curriculum and give more guideline for identifying the core of fisheries business administration. The method of analysing that in this research has adopt the social network analysis(SNA) and automated software tool which is the most dominant technique in contents analysis including the Krkwics and Pajek. The SNA is evaluated that most popular, rigorous and firm methodology for analyzing, examining and revising some concepts or objects in the context of semantics. The result of this study shows that the ratio of fisheries business administration class has been decreased but still the most fulfilled course. And English mediated class has been avoided though that sort of the class has been increased. In the view point of course fulfillment, it has been potential and inefficient problems that some classes that including financial related and accounting related class would not been accomplished appropriately. The findings of a graduate depth interview which has been done about 4 years for understanding that student show that there's some recognition gap of fisheries business administration in staffs of human resource management. And the level of job satisfaction in fisheries business still somewhat low and even worse the chance of recruitment also unsteady.

The condition and the analysis of the problems of the Japanese - The change of the Korean geriatric security law - (일본 유료 노인홈의 현황과 그 문제점 분석 - 우리나라 노인 복지법 개정에 즈음하여 -)

  • 신경주
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 1993.09a
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    • pp.13-20
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    • 1993
  • In Korea, the elderly support has been accomplished by the families in the extended family system with the influence of the transmigration and the confucianism thought. But in Korea the drastic changes of society such as, the growth of the elderly pollution, the urbanization, the decrease of the birth rate, the increase of the working women, the growth of the nuclear families, etc., make the family difficult to take care of the elderly. Therefore, some people insist on the construction of the elderly home as the way to solve the elderly problems and some of corporations including profit-organizations are ready to participate the construction of the elderly home. They force the change of the current social security law because it is impossible to carry out the plans uncer the law. At this point, the conditions of the elderly home in Japan which is geographically close to Korea and has facillicated the elderly home business were examined at the consumer perspectives. The purpose of this study were to consider the possible problems in the elderly home and to prevent from happening another elderly problems in the future.

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Evaluation of regional ecosystem by landscape ecological measure - Case study in Yongin City - (경관지수를 이용한 지역생태계 평가 - 용인시를 대상으로 -)

  • Cho, Yong-Hyeon
    • Journal of Environmental Impact Assessment
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    • v.9 no.4
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    • pp.349-362
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    • 2000
  • In the study, the feasibility of landscape ecological measures as indices system for interpretation and evaluation of regional ecosystem was investigated through the application to Yongin City. Each patch metrics well showed the class structure and supplemented the class metrics, and class metrics also showed well the landscape structure and supplemented the landscape metrics. And the change analysis through subtraction of two set of landscape ecological measurement in two point of time showed the dynamic trends very well. One of the dynamic trends in Yongin City was the rapid fragmentation. While there was no landcover data on Yongin City, using Landsat data and remote sensing techniques were proved to be efficient and effective to produce the digital landcover data.

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Derivation of Design Flood Using Multisite Rainfall Simulation Technique and Continuous Rainfall-Runoff Model

  • Kwon, Hyun-Han
    • Proceedings of the Korea Water Resources Association Conference
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    • 2009.05a
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    • pp.540-544
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    • 2009
  • Hydrologic pattern under climate change has been paid attention to as one of the most important issues in hydrologic science group. Rainfall and runoff is a key element in the Earth's hydrological cycle, and associated with many different aspects such as water supply, flood prevention and river restoration. In this regard, a main objective of this study is to evaluate design flood using simulation techniques which can consider a full spectrum of uncertainty. Here we utilize a weather state based stochastic multivariate model as conditional probability model for simulating the rainfall field. A major premise of this study is that large scale climatic patterns are a major driver of such persistent year to year changes in rainfall probabilities. Uncertainty analysis in estimating design flood is inevitably needed to examine reliability for the estimated results. With regard to this point, this study applies a Bayesian Markov Chain Monte Carlo scheme to the NWS-PC rainfall-runoff model that has been widely used, and a case study is performed in Soyang Dam watershed in Korea. A comprehensive discussion on design flood under climate change is provided.

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The Analysis of the Slope Stability for the Small Dam (Small Dam의 斜面安定 解析)

  • Choi, Ki-Bong;Bae, Woo-Soek
    • Journal of the Korean Society of Safety
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    • v.19 no.2
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    • pp.88-92
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    • 2004
  • The paper decribes a procedure for the evaluation of the effect of seepage force on stability of slopes. The stability of an embankment impounding a water reservoir is highly depend upon the location of seepage line with the embankment. To evaluate the accurate safety factor of an embankment, it is important to illustrate the seepage phenomenon. Of particular interest is the stability following a rapid change of reservoir level. Seepage forces in embankments are easily determined interest is the stability following a rapid change of resrvoir level. Seepage forces in embankments are easily detemined if frictional forces are expressed in relation to hydraulic gradient I. If a piezometer is inserted into a body of embankment, the level to which fee water rises is a measure of the energy at that point.