• Title/Summary/Keyword: Ground observation

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Analysis of Optimal Resolution and Number of GCP Chips for Precision Sensor Modeling Efficiency in Satellite Images (농림위성영상 정밀센서모델링 효율성 재고를 위한 최적의 해상도 및 지상기준점 칩 개수 분석)

  • Choi, Hyeon-Gyeong;Kim, Taejung
    • Korean Journal of Remote Sensing
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    • v.38 no.6_1
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    • pp.1445-1462
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    • 2022
  • Compact Advanced Satellite 500-4 (CAS500-4), which is scheduled to be launched in 2025, is a mid-resolution satellite with a 5 m resolution developed for wide-area agriculture and forest observation. To utilize satellite images, it is important to establish a precision sensor model and establish accurate geometric information. Previous research reported that a precision sensor model could be automatically established through the process of matching ground control point (GCP) chips and satellite images. Therefore, to improve the geometric accuracy of satellite images, it is necessary to improve the GCP chip matching performance. This paper proposes an improved GCP chip matching scheme for improved precision sensor modeling of mid-resolution satellite images. When using high-resolution GCP chips for matching against mid-resolution satellite images, there are two major issues: handling the resolution difference between GCP chips and satellite images and finding the optimal quantity of GCP chips. To solve these issues, this study compared and analyzed chip matching performances according to various satellite image upsampling factors and various number of chips. RapidEye images with a resolution of 5m were used as mid-resolution satellite images. GCP chips were prepared from aerial orthographic images with a resolution of 0.25 m and satellite orthogonal images with a resolution of 0.5 m. Accuracy analysis was performed using manually extracted reference points. Experiment results show that upsampling factor of two and three significantly improved sensor model accuracy. They also show that the accuracy was maintained with reduced number of GCP chips of around 100. The results of the study confirmed the possibility of applying high-resolution GCP chips for automated precision sensor modeling of mid-resolution satellite images with improved accuracy. It is expected that the results of this study can be used to establish a precise sensor model for CAS500-4.

Evaluation of bias and uncertainty in snow depth reanalysis data over South Korea (한반도 적설심 재분석자료의 오차 및 불확실성 평가)

  • Jeon, Hyunho;Lee, Seulchan;Lee, Yangwon;Kim, Jinsoo;Choi, Minha
    • Journal of Korea Water Resources Association
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    • v.56 no.9
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    • pp.543-551
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    • 2023
  • Snow is an essential climate factor that affects the climate system and surface energy balance, and it also has a crucial role in water balance by providing solid water stored during the winter for spring runoff and groundwater recharge. In this study, statistical analysis of Local Data Assimilation and Prediction System (LDAPS), Modern.-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2), and ERA5-Land snow depth data were used to evaluate the applicability in South Korea. The statistical analysis between the Automated Synoptic Observing System (ASOS) ground observation data provided by the Korea Meteorological Administration (KMA) and the reanalysis data showed that LDAPS and ERA5-Land were highly correlated with a correlation coefficient of more than 0.69, but LDAPS showed a large error with an RMSE of 0.79 m. In the case of MERRA-2, the correlation coefficient was lower at 0.17 because the constant value was estimated continuously for some periods, which did not adequately simulate the increase and decrease trend between data. The statistical analysis of LDAPS and ASOS showed high and low performance in the nearby Gangwon Province, where the average snowfall is relatively high, and in the southern region, where the average snowfall is low, respectively. Finally, the error variance between the four independent snow depth data used in this study was calculated through triple collocation (TC), and a merged snow depth data was produced through weighting factors. The reanalyzed data showed the highest error variance in the order of LDAPS, MERRA-2, and ERA5-Land, and LDAPS was given a lower weighting factor due to its higher error variance. In addition, the spatial distribution of ERA5-Land snow depth data showed less variability, so the TC-merged snow depth data showed a similar spatial distribution to MERRA-2, which has a low spatial resolution. Considering the correlation, error, and uncertainty of the data, the ERA5-Land data is suitable for snow-related analysis in South Korea. In addition, it is expected that LDAPS data, which is highly correlated with other data but tends to be overestimated, can be actively utilized for high-resolution representation of regional and climatic diversity if appropriate corrections are performed.

Aspects of Emotional Customs by the N-po Generation (N포세대의 감정 풍속도)

  • Seo, Yeon-Ju
    • Journal of Popular Narrative
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    • v.25 no.1
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    • pp.55-85
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    • 2019
  • In this article, we examine the real meaning behind the stories in which the N-po Generation (Millennial Generation) is depicted, through the observation of entertainment programs, TV series, and movies. This could be an opportunity to investigate the aspects of emotional customs of our era, which have been described by television media as portraying the complex and multifaceted reality in the most mundane and popular manner while influencing the public. Problems with youth unemployment, the polarization of life, and instability are not only global issues but situations that specifically occur in South Korea. It is thus vital to pay attention to the inner side of the N-po Generation who enjoy Sohwakhaeng (small but certain happiness) by eating alone as the placebo effect of this tough reality. This is an agenda that should be viewed as a problem in the fundamental design of South Korean society. The consciousness of the problem shown in the TV series has been drawing attention. The TV series Because depicts a love narrative that concentrates on emotions in a relationship that started between housemates due to poverty and housing problems, leading to marriage. Thus, the TV series persuasively dramatized 'confluent love' in the N-po Generation. In the movie , Miso can be regarded as a symbol that represents the emergence of a new generation of cultural sensitivity. There is a suggestion in the sequence of that identifies the pursuit of taste with the discovery of identity. The TV series is a growth narrative that deals heavily with youth unemployment, temporary workers, fragmented families, and dating violence. The housemates in find emotional stability through interaction with each other, and courageously approach their individual problems. In the process, images of women, who are empathetic towards others and are willing to jointly solve their problems, are calmly depicted to reveal a story of growth revolving around a ground emotional community. The current problem that South Korean society should contemplate is how to be fully human beyond mere survival, and how to further seek the conditions of human existence. In that sense, what we should pursue is a notion of 'publicness', which can put several generations together. Because of the reality that confliction between generations must be triggered, in order to make a passage of sympathizing, mass media's sensitivity training becomes more important. This may be the duty of mass media.

Retrieval of Hourly Aerosol Optical Depth Using Top-of-Atmosphere Reflectance from GOCI-II and Machine Learning over South Korea (GOCI-II 대기상한 반사도와 기계학습을 이용한 남한 지역 시간별 에어로졸 광학 두께 산출)

  • Seyoung Yang;Hyunyoung Choi;Jungho Im
    • Korean Journal of Remote Sensing
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    • v.39 no.5_3
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    • pp.933-948
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    • 2023
  • Atmospheric aerosols not only have adverse effects on human health but also exert direct and indirect impacts on the climate system. Consequently, it is imperative to comprehend the characteristics and spatiotemporal distribution of aerosols. Numerous research endeavors have been undertaken to monitor aerosols, predominantly through the retrieval of aerosol optical depth (AOD) via satellite-based observations. Nonetheless, this approach primarily relies on a look-up table-based inversion algorithm, characterized by computationally intensive operations and associated uncertainties. In this study, a novel high-resolution AOD direct retrieval algorithm, leveraging machine learning, was developed using top-of-atmosphere reflectance data derived from the Geostationary Ocean Color Imager-II (GOCI-II), in conjunction with their differences from the past 30-day minimum reflectance, and meteorological variables from numerical models. The Light Gradient Boosting Machine (LGBM) technique was harnessed, and the resultant estimates underwent rigorous validation encompassing random, temporal, and spatial N-fold cross-validation (CV) using ground-based observation data from Aerosol Robotic Network (AERONET) AOD. The three CV results consistently demonstrated robust performance, yielding R2=0.70-0.80, RMSE=0.08-0.09, and within the expected error (EE) of 75.2-85.1%. The Shapley Additive exPlanations(SHAP) analysis confirmed the substantial influence of reflectance-related variables on AOD estimation. A comprehensive examination of the spatiotemporal distribution of AOD in Seoul and Ulsan revealed that the developed LGBM model yielded results that are in close concordance with AERONET AOD over time, thereby confirming its suitability for AOD retrieval at high spatiotemporal resolution (i.e., hourly, 250 m). Furthermore, upon comparing data coverage, it was ascertained that the LGBM model enhanced data retrieval frequency by approximately 8.8% in comparison to the GOCI-II L2 AOD products, ameliorating issues associated with excessive masking over very illuminated surfaces that are often encountered in physics-based AOD retrieval processes.

A Study of the Impractical Area and Boundary of an Outer Royal Garden "Hamchunwon" Attached to Gyeonghuigung Palace (경희궁 별원(別苑) 함춘원의 실지(實地) 경역 고찰)

  • Jung, Woo-Jin;Hong, Hyeon-Do;So, Hyun-Su
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.40 no.1
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    • pp.26-42
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    • 2022
  • The purpose of this study is to examine and understand the area and the original outer boundaries of Hamchunwon(含春苑), which was the outer royal garden of Gyeonghuigung Palace, which existed before the site of the Russian legation. The results of the study are as follows. First, examining the 3 types of drawings prepared for securing the Russian legation's site and constructing a new building, it was confirmed that two low peaks, which appear to be the original terrain of Hamchunwon, existed in the north and south directions inside the site. According to the initial plan of the of the legation's site, it appears that the entrance of the legation building is connected to the Saemunan-ro in the northwest. However, according to the report made at the time when the Russian temporary minister Veber purchased the legation's site, it was recorded that the site already had a narrow entrance and a dirt road in place, and hence, it was connected to Saemunan-ro. This fact makes it possible to learn that the line of movement for officials and the original gate were located to the northwest of the site planned as the entrance of the legation building towards Hamchunwon. Second, the site was created by cutting the top of the high hill at the time of the construction of the legation building, and as a result, a two tiered staircase typed terrace was built. The ground on which the main building and the secretary's building, etc., were erected was made by cutting the highest peak and solidifying it flat, and a large quantity of soil was used for grading. In the case of the northern area of the main building, the traces of leveling the terrain by cutting the mountains are apparent, and an observation typed garden with a walking path and pavilion was formed by utilizing the physical environment equipped with an easy view. This may be considered as a use which is consistent with the topographical conditions of creating an outer royal garden to block the civilian views on a high terrain overlooking the palace. Third, Hamchunwon's fences were partially exposed in the photos from the 1880s through the 1890s, which demonstrate the spatial changes made around the US, UK, and the Russian legations. As a result of the photo analysis performed, Hamchunwon occupies the northern area of the Russian legation's site, and it is estimated that the north, west, and east walls of the legation resembled those of Hamchunwon. The area to the south of the Russian legation was originally a place made available for civilian houses, and it was possible to examine the circumstances of purchasing dozens of civilian houses and farmlands according to various materials. Fourth, Hamchunwon, which was formed as the outer royal garden of Gyeongdeokgung Palace of Lord Gwanghaegun, lost its sense of place as an outer royal garden when the entire building of Gyeonghuigung Palace was torn down and used as a construction members during the reconstruction of Gyeongbokgung Palace, and faded away as the site was sold to Russia around 1885. The area where Hamchunwon used to be located transformed into a core space of the Russian legation where the main building and garden were located after the construction of the new building. Hence, Hamchunwon, which was limited to the northern area of the Russian legation, does not carry the temporal and spatial context with Gyeongungung Palace and Seonwonjeon which were constructed after 1897, and it is determined that the view of Seonwonjeon as Baehoorim or Baegyeongrim is not valid.

A Study on the Religiosity of Filial Piety Ethics in Daesoonjinrihoe (대순진리회의 효 윤리에 나타난 종교성 연구)

  • Cha, Seon-keun
    • Journal of the Daesoon Academy of Sciences
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    • v.27
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    • pp.171-200
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    • 2016
  • This paper will analyze the filial piety based ethics of Daesoonjinrihoe (大巡眞理會) and the traditional filial piety of Confucianism (儒敎), Buddhism (佛敎) and Taoism (道敎) through comparing and contrasting their unique systems. The traditional Korean ethics regarding filial piety are in great need of reformation as the relationship between the parents and children should not be vertical or unilateral but parallel and reciprocal. However, there have not been sufficient in-depth studies on this specific ideology and alternative approaches. Regarding this prospect, one representative Korean indigenous new religion, Daesoonjinrihoe has emerged and directly engages in the collision between traditionalism and modernity. The modernity of Daesoonjinrihoe, enables the observation of how the filial piety based ethics have developed within a system of doctrine and thereby provides an exemplary model of traditional filial piety reimagined in accordance with modern sensibilities. A brief summary of comparative findings is as follows: First, Daesoonjinrihoe and Confucianism have taken serving parents with respect as an ethic within filial piety, but Confucianism engenders this ideal through the unilateral and unconditional sacrifice of younger people based on patriarchal feudalism whereas Daesoonjinrihoe has rejected such unilateral sacrifice and instead promotes mutual beneficience between parents and children. This difference occurs, in part, due to the filial piety of Confucianism rising in the midst of the feudal order whereas the ideology of Daesoonjinrihoe contains ideals such as "the reciprocation of favor for mutual beneficence (報恩相生)" and "respect for humanity (人尊)," both of which serve as key principles of the new religious world as envisioned by Daesoonjinrihoe. Second, filial piety in Buddhism and Taoism tends to be passive and inactive and is often expressed by praying for happiness and longevity for one's parents while they are alive and later praying for the heavenly rebirth of one's parents after they die. The filial piety of Daesoonjinrihoe also partially contains such ideas, however; they are extended much further and arrive upon novel and profound expressions. The spectrum of the filial piety in Daesoonjinrihoe expands to the extent children perform actions to resolve their parent's sins and pave a new road for their parents. This filial piety requires a cultivation practice from both parents and children. This system of dual cultivation was established because the world-view of Daesoonjinrihoe enables both parents and children to enjoy happiness and wealth both of which are achieved through the completion of religious objectives following cultivation practice. Third, Confucianism and Daesoonjinrihoe hold memorial services for ancestors with sincerity as an expression of filial piety. Filial piety in the Confucian context excludes ideas from Shamanism and thereby memorial services are held for impersonal entities, however; in the Daesoonjinrihoe context, memorial services are held for personal-entities. Accordingly, holding a memorial service for ancestors with sincerity has a greater sense of realism in Daesoonjinrihoe than it does in Confucianism. Fourth, while Confucianism and Daesoonjinrihoe both aim to requite the grace received from ancestors, the contents of grace and reciprocation of favors (報恩) are viewed differently. In Confucianism, since the ancestors existed previously and bestowed the gift of life to their children and indirectly, all of their descendents. Therefore, memorial services for ancestors are held to convey gratitude and filial piety. However, in Daesoonjinrihoe, ancestors not only bestowed the gift of earthly life to their descendents, in the spirit realm, ancestral spirits also spend sixty years accumulating the merit necessary to imbue each of their descendents with spiritual insight. Consequently, filial piety is expressed through memorial services as well as spiritual cultivation. Fifth, in Confucianism, achieving the fame and prestige indicative of success in the mundane world can be an act of filial piety as it would bring pride to one's ancestors, but in Daesoonjinrihoe, succeeding in religious objectives through spiritual cultivation is considered to be a higher form of filial piety. Sixth, Confucianism, Buddhism and Taoism all observe filial piety as system of familial ethics based in morality. This is likewise true of Daesoonjinrihoe, however; Daesoonjinrihoe confers greater importance on filial piety as an essential form of ethics for religious redemption. This is due to the Daesoon interpretation that the absence of filial piety was the direct cause which led to the sickened state of the world and its collapse. Forgetting the grace of parents who have given the gift of life or the grace of ancestral spirits who have accumulated merit on behalf of their descendents are acts of ingratitude which are unacceptable during the period of Reordering of the Universe. Judging from these findings, Daesoonjinrihoe embraces parts of traditional filial piety as it exists in Confucianism, Buddhism and Taoism, but it does so on the ground of its own unique culture. Through re-interpretation and re-creation, ideas regarding filial piety are being further developed. Namely, filial piety in Daesoonjinrihoe is regulations founded upon the reciprocation of favors for mutual beneficence and respect for humanity. Therefore, it is understood as a concept wherein one's own cultivation practice is performed in order to reach religious objectives, the perfection of personal character, and spiritual insight. This requires that even recipents of filial piety (i.e., parents) perform certain cultivation practices to enjoy happiness and wealth. Additionally, filial piety in Daesoonjinrihoe manifests a reinforced religious character and also serves as a system ethics which is soteriologically essential for salvation during the period known as the Reordering of the Universe.