• 대기
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• 제24권2호
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• pp.245-251
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• 2014

Statistical trajectory analysis has been widely used to identify potential source regions for chemically and radiatively important chemical species in the atmosphere. The most widely used method is a statistical source-receptor model developed by Stohl (1996), of which the underlying principle is that elevated concentrations at an observation site are proportionally related to both the average concentrations on a specific grid cell where the observed air mass has been passing over and the residence time staying over that grid cell. Thus, the method can compute a residence-time-weighted mean concentration for each grid cell by superimposing the back trajectory domain on the grid matrix. The concentration on a grid cell could be used as a proxy for potential source strength of corresponding species. This technical note describes the statistical trajectory approach and introduces its application to estimate potential source regions of $CO_2$ enhancements observed at Korean Global Atmosphere Watch Observatory in Anmyeon-do. Back trajectories are calculated using HYSPLIT 4 model based on wind fields provided by NCEP GDAS. The identified $CO_2$ potential source regions responsible for the pollution events observed at Anmyeon-do in 2010 were mainly Beijing area and the Northern China where Haerbin, Shenyang and Changchun mega cities are located. This is consistent with bottom-up emission information. In spite of inherent uncertainties of this method in estimating sharp spatial gradients within the vicinity of the emission hot spots, this study suggests that the statistical trajectory analysis can be a useful tool for identifying anthropogenic potential source regions for major GHGs.

• 대한조선학회논문집
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• 제30권2호
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• pp.98-111
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• 1993

2차원 비정상 비선형 자유표면파를 해석하고 자유표면파에서의 점성효과를 관찰하였다. 유동장내의 Navier-Stokes 방정식과 연속방정식을 풀기 위해 유한해석법을 적용하였고, 자유표면의 처리를 위해 MAC 기법을 적용하였다. 그리고, 자유표면에서는 표면장력을 고려한 경계조건을 적용하였으며, 층류에 대한 점성효과만을 고려하였다. 계산모델은 천수역에서의 점성영향, 자유표면 근처에서의 보오텍스 쌍(vortex-pair)의 거동 및 전진하는 부유체 앞에서의 자유표면파문제 등이다. 천수역문제에서는 바닥과의 마찰에 기인한 자유표면파의 변화를 고찰하였으며, 특히 고립파에 대한 적용으로서 파고의 감소정도, 수직벽면에서의 파상승(wave run-up) 및 수심의 변화로 인한 유장변화 등을 살펴보았다. 보오텍스 문제에서는 보오텍스의 이동에 따른 자유표면주위의 유동변화를 관찰하였으며, 사각부유체 주위의 유동문제에서는 전진속도의 차이에 따른 자유표면파의 차이 및 물체주위의 유동특성을 관찰하였다.

• 대한지리학회지
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• 제42권2호
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• pp.196-217
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• 2007

로스앤젤레스 한인타운은 지난 10여 년에 걸쳐 소수민족 이민자들의 엔클레이브(enclave)에서 초국적 경제공간으로 변모하고 있다. 도시정부의 재개발 계획과 지역 한인들의 경제재활성화를 위한 노력이 진행됨과 동시에, 한국으로부터의 초국적 행위자들은 기업부문뿐만 아니라 부동산 시장에 공격적으로 투자하고 있다. 그러나 모순적이게도 이러한 다중스케일적 지리적 변동은 한인타운을 로스앤젤레스에서 가장 빈곤하고 위험한 내부도시의 하나로 전락시키는 데에 기여하고 있다. 본 논문은 장소에 기반한 아래로부터의 접근을 토대로 이러한 공간적 모순의 본질을 탐색하는데, 특히 헤게모니를 쥔 로컬 행위자들, 도시정부, 초국적 행위자들이 형성하는 다중스케일적 네트워크가 최근 한인타운이 지니는 일상적 삶과 유리된 재현의 경제를 발달시키고 있음을 지적한다. 또한, 본 연구는 이러한 한인타운의 도시재생이 이 구역에 거주하는 한인들과 라티노 노동자들을 포함하는 커뮤니티 구성원을 배제시키고 착취하고 있음을 밝히고자 한다. 결론적으로 본 연구는 한인타운의 지속가능한 미래는 민족 담론을 극복하고 인종, 민족을 횡단할수 있는 '장소기반의' 커뮤니티 의식에서 논의되어야 함을 주장한다.

• 디지털콘텐츠학회 논문지
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• 제19권1호
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• pp.85-91
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• 2018

대부분의 은행은 고객 세분화를 위해 성별, 나이, 직업, 주소 등 인구통계정보만을 사용하고 있으나, 이는 고객의 다양한 금융행동 패턴을 반영하지 못하는 단점이 있다. 본 연구에서는 은행 내 다양한 빅데이터를 융합하여 문제점을 해결함과 동시에 향후 많은 은행에서 폭넓게 활용될 수 있는 고객 세분화 방법을 개발하는 것을 목표로 한다. 본 연구에서 제안한 블록을 만들어 이 블록을 클러스터링하는 상향식 방식의 세분화는 기법을 제안한다. 이 방식은 기존의 인구통계정보 뿐만 아니라 다양한 거래패턴, 채널접촉패턴에 기반을 둔 고객의 다양한 금융니즈를 정교하게 반영할 수 있다는 장점이 있다. 세분화를 통해 고객의 금융니즈를 보다 정교하게 반영한 적정 동료그룹을 찾아 이를 기반으로 상품추천, 금융니즈 등급 산출, 고객이탈 예측 등 다양한 마케팅 모델을 개발하여 실제 농협은행 마케팅에 활용할 것이다.

• 대한조선학회논문집
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• 제53권2호
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• pp.154-161
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• 2016

There are several existing studies for the weight estimation of offshore plants. However, most of them were applicable at the pre-FEED (Front End Engineering Design) stage. In this paper, a preliminary study on a method for the weight estimation and calculation of offshore EPC (Engineering Procurement Construction) projects is made for the use at the estimation stage after FEED. Based on literature surveys including ISO (International Organization for Standardization) 19901-5 about weight estimation, we proposes new weight factors and a weight curve. Weight factors defined in this study include MTO (Material Take-Off), estimated weight, FEED maturity factor, allowance factor, and contingency factor. The proposed method utilizes bottom-up approach for weight estimation and it can be used for the weight estimation and calculation of offshore EPC projects at the estimation stage.

• 한국어교육
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• 제29권4호
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• pp.169-199
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• 2018

The purpose of this study is to examine Korean teachers' needs in in-service teacher training and variables related to their needs. This study was conducted with teachers from Korean language centers in Korean universities. The following three research questions were investigated: (1) What are the teachers' experiences of Korean language teaching and in-service teacher training? (2) What are the teachers' needs and expectations for the content and components of in-service education programs? Are there any disparity between teachers' needs and institutional needs? (3) What are the variables to be considered in designing an effective in-service teacher education program? In order to answer the research questions, a survey was developed and distributed to university Korean language institutions and Korean language teachers. The results indicated that both institutions and teachers are highly aware of the importance of the need for in-service teacher training. The results also suggested that a more teacher-centered, bottom-up approach should be implemented for successful outcomes of teacher education programs. Based on the results, this study offers a summary of the need for in-service teacher training and variables (both individual teacher variables and environmental variables) to be considered in designing the content and components of a teacher education program.

• Ocean and Polar Research
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• 제45권2호
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• pp.71-87
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• 2023

Climate change causes ocean warming, ocean acidification, sea-level rise, dynamic coastal risk, change of ecosystem structure and function, and degradation of ecosystem services. Not only that, but it has negatively impacted the well-being of people, society, and culture, including food security, water resources, water quality, livelihood, health, welfare, infrastructure, transport, tourism, recreation, and so on, especially by particularly degrading indigenous communities and generating an inequitable distribution of benefits and costs. As pointed out here, these adverse impacts of climate change on the ocean have been emphasized at the international and national levels. In contrast, the ocean field has been neglected in the climate change conversation for too long. However, since the UNFCCC COP 25, the ocean has been drawn into the discussion as a solution to address climate change. Moreover, the U.S. Congress recently unveiled a bill called the 'Ocean-Based Climate Solution Act, OBCSA' that reflects the new paradigm of the international regime. The comprehensive legislative bill includes elements related to climate inequity, a blue economy, and a community-led bottom-up policy mechanism, which will have a significant bearing on the ocean-climate legal system. Therefore, this study reviews the OBCSA and deduces implications with regard to the ocean-climate legal system in Korea.

• 의정연구
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• 제27권2호
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• pp.41-70
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• 2021

바이든 행정부의 동북아 정책은 트럼프 행정부의 정책과 어떤 면에서 유사하고 어떤 면에서 다를 것인가? 본 논문은 트럼프 행정부로부터 바이든 행정부로의 이행에 따라 미국의 동북아 정책에 다음과 같은 변화와 연속성이 나타날 것이라고 제시한다. 미국 외교의 전통적 원칙과 관행을 중시하는 바이든 행정부의 성향상, 트럼프 시기와는 달리 미국의 동북아 정책에 있어 높은 안정성과 예측 가능성이 예상된다. 강력한 대중 압박 정책은 바이든 행정부에서도 지속될 것이며, 이에 따라 미중 대립은 더욱 지속·심화될 것이다. 한편 북한에 대해 바이든 행정부는 파격적 '그랜드 바겐'을 시도한 트럼프와는 달리 보수적 상향식 접근법을 취할 것으로 예상되며, 북한 정권의 협상 의도 및 태도에 회의적 관점을 가지고 있어 극적인 북미관계 진전은 당분간 어려워 보인다. 한국과 일본에 대해 바이든은 트럼프와 달리 양국을 동맹으로 중시하고 존중하는 태도를 보일 것이나, 심화되는 미중 갈등 속에서 한일 양국이 중국 견제에 있어 더 큰 역할을 수행하길 요구할 가능성이 높다.

• 한국기후변화학회지
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• 제10권3호
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• pp.237-242
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• 2019

Ammonia is main precursor gas of secondary particulate matter and contributes almost 78% of total ammonia emission from the agricultural sector in Korea. The current method of estimating ammonia emission from fertilizer application, which contributes 7% of the total emission, has high uncertainty and needs to be improved to better predict PM2.5 concentration. In this study, we suggest an improvement method for ammonia emission quantification from fertilizer application. The first improvement was in the emission factor of NPK fertilizer by conducting a field study to verify the currently used factor. The improved NPK emission factor of 52.2 kg NH ton-1N was confirmed by comparing with the value from the EEA (European Environment Agency) and adjusting the value for the Korean climate and soil conditions. We also improved the amount of fertilizer usage by including the sales amount to the fertilizer supply amount of the Korean Farmers Association, increasing total fertilizer usage by 39.8%. As the statistical data on fertilizer supply and sales are compiled yearly, we estimated monthly emission of ammonia by considering cultivated areas and timing of fertilization for each crop. In summary, we suggest a novel and practical method to improve estimation methodology of ammonia emission from the field of fertilizer application: 1) emission factor of NPK fertilizer was reconfirmed; 2) total amount of fertilizer use was revised considering fertilizer sales; and 3) monthly emission of ammonia was realized by considering different crop practices. A bottom-up approach to compile activity data is needed to increase the estimation accuracy of monthly emission of ammonia, which is very helpful for predicting PM2.5 concentration.

• 자원환경지질
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• 제57권1호
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• pp.25-39
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• 2024

The Téra manganese deposit represents the most significant manganese mineralization discovered in Niger up today. The main host rocks of this ore are gondites, which are a garnet and quartz rich metamorphic rocks. The supergene weathering developed an alteration profile on these gondites. This study aims to identify the mineralogical composition of gondites and associated rocks, in order to highlight the origine of rocks and the manganese enrichment. The methodological approach adopted involved a field study followed by polarizing microscopic analysis using transmitted and reflected lights. Additionally, quantitative X-ray diffraction (XRD) analysis was performed to assess the manganese ore minerals present in the gondite and associated rocks, including mica schists, amphibolites, and quartzites. The petrographic study revealed a paragenesis characterized by the presence of kyanite, staurolites, garnets and plagioclases that are generally poikiloblasts with quartz and opaque minerals inclusions, emphasizing the internal schistosity which is planar, helicitic or microfolded. These features indicate a prograde metamorphism until high-pressure amphibolite facies conditions. These conditions are followed by greenschist facies conditions marked by calcite, epidote, muscovite, chlorite and muscovite assemblage which emphasizes the vertical tectonics. Depending on the alteration process, the manganese ore exhibit a granular texture at the bottom of the gondite hills, transitioning to a colloform texture towards the top, passing through the epigenization and replacement texture. The XRD analysis further revealed that the studied rocks originated from a volcano-sedimentary complex, characterized by alternating marly, arenaceous and pelitic sequences associated with submarine exhalations.