A Review on International Carbon Credit Certification Methodologies for Biochar as a Soil Amendment

한경화,윤석인,곽진협,이선일 한국토양비료학회 2023 한국토양비료학회지 Vol.56 No.4

The high organic carbon (Corg) sequestration ability of biochar can greatly contribute to atmospheric CO2 removal for global C neutrality. These climate-positive services of biochar are traded as C credits on international C trading platforms through reliable methodologies. Here, we reviewed the international biochar C credit certification methodologies and quality standards to build foundations for biochar C credit trading in Korea. The quality of biochar includes the quantity of Corg sequestered over 100 years, the content of toxic contaminants below their threshold values, and the biochar properties related to soil fertility, as described by European Biochar Certificate (EBC) and International Biochar Initiative (IBI) certification guidelines. The higher amount of Corg sequestered over 100-year in biochar is ascribed to the lower the molar H/Corg and O/ Corg ratios, resulting from pyrolysis of feedstock at a high temperature over 350°C. For assuring the permanence of biochar, the threshold value of molar H/Corg ratio is 0.7 in both EBC and IBI. Besides, EBC standards also have the threshold value 0.4 of a molar O/Corg ratio for all biomass and require a pyrolysis condition of exceeding 500°C for 3 min at minimum for animal-derived biomass. Quality-certified biochar can be used for C credits. Biochar C credit is the amount of net CO2-eq removed over 100-year by the biochar activity, i.e., biochar Corg sequestered over 100-year minus greenhouse gas (GHG) emissions over the biochar life cycle. The three voluntary C credit trade platforms with their own biochar methodologies are Puro.earth with life cycle assessment, Carbonfuture with C-sink certification, and Verra with UNFCCC Clean development mechanism (CDM) methodology. All three methodologies present standards for permissible biomass for feedstock, energy efficiency and by-product treatment for production, permissible matrices and tracking system for end use, and the third-party verrification. On a regional basis in Korea, where biochar feedstock is mainly biogenic waste, GHG emissions during biochar lifetime mainly depend on the production stage. In pyrolysis facilities that meet EBC and Verra’s high-tech standards, GHG emissions during the production stage could be assumed to be very low. However, low-tech facilities with high GHG emissions during biochar production could deteriorate biochar C credits. Therefore, securing biochar C credits could be achieved through the modernization of pyrolysis facilities. Besides, it is essential to establish a process-oriented measurement, reporting, and verification systems, to ensure scientific reliability of biochar C credit certification

수학 교실의 사회적 규범이 수학적 신념에 미치는 영향

한경화,강순자,정인철 한국학교수학회 2005 韓國學校數學會論文集 Vol.8 No.3

본 연구는 수학적 신념에 대한 검사지를 활용한 조사연구와 수학 교실 비디오 촬영을 통해 수학 교실에 새로운 사회적 규범이 형성되었을 때 수학적 신념의 변화가 일어나는지 알아보고 수학 교실의 문화 분석을 통해 학생들의 수학적 신념에 영향을 주는 수학 교실의 사회적 규범을 찾고자 하였다. 연구 결과는 일반적인 사회적 규범에만 초점을 두는 수업으로는 학생들의 수학적 신념을 변화시키기에 충분하지 않았다. 또한 수학 교실의 문화분석을 통해 살펴본 수학 교실의 사회수학적 규범은 학생들의 수학적 신념에 영향을 미쳤다.

How to Develop, Validate, and Compare Clinical Prediction Models Involving Radiological Parameters: Study Design and Statistical Methods

한경화,송기준,최병욱 대한영상의학회 2016 Korean Journal of Radiology Vol.17 No.3

Clinical prediction models are developed to calculate estimates of the probability of the presence/occurrence or future course of a particular prognostic or diagnostic outcome from multiple clinical or non-clinical parameters. Radiologic imaging techniques are being developed for accurate detection and early diagnosis of disease, which will eventually affect patient outcomes. Hence, results obtained by radiological means, especially diagnostic imaging, are frequently incorporated into a clinical prediction model as important predictive parameters, and the performance of the prediction model may improve in both diagnostic and prognostic settings. This article explains in a conceptual manner the overall process of developing and validating a clinical prediction model involving radiological parameters in relation to the study design and statistical methods. Collection of a raw dataset; selection of an appropriate statistical model; predictor selection; evaluation of model performance using a calibration plot, Hosmer-Lemeshow test and c-index; internal and external validation; comparison of different models using c-index, net reclassification improvement, and integrated discrimination improvement; and a method to create an easy-to-use prediction score system will be addressed. This article may serve as a practical methodological reference for clinical researchers.

친환경농업 - 토양 떼알구조 안정화로 온실가스 줄인다.

한경화,Han, Gyeong-Hwa 전국농업기술자협회 2010 농업기술회보 Vol.47 No.2

임신기간에 따른 정상 임부가 자각한 피로 정도의 차이

한경화,배효숙,기부성,최선희,김선희,장희영,강지호 이화여자대학교 의과대학 1999 임상간호연구지 Vol.4 No.-

혼합모형을 이용한 반복 측정된 변수들 간의 상관분석

한경화,정인경,Han, Kyunghwa,Jung, Inkyung 한국통계학회 2015 응용통계연구 Vol.28 No.2

Repeated measurements on each variables of interest often arise in bioscience or medical research. We need to account for correlations among repeated measurements to assess the correlation between two variables in the presence of replication. This paper reviews methods to estimate a correlation coefficient between two variables in repeated measurements using the variance-covariance matrix of linear mixed effect models. We analyze acoustic radiation force impulse imaging (ARFI) data to assess correlation between three shear wave velocity (SWV) measurements in liver or spleen and spleen length by ultrasonography. We present how to obtain parameter estimates for the variance-covariance matrix and correlations in mixed effects models using PROC MIXED in SAS. 생명과학 또는 의학 연구에서는 반복 측정된 변수들 간의 상관 관계를 보고자 하는 경우가 발생한다. 반복 측정된 것을 고려하지 않으면 상관관계를 과소 추정하는 경향이 나타나므로 이를 고려해야 하며, 선형혼합모형의 분산-공분산 행렬을 이용하여 상관관계를 추정할 수 있다. 본 연구에서는 변수들의 반복 측정이 동시에 된 경우와 그렇지 않은 경우로 나누어 혼합모형을 이용한 상관계수의 추정방법을 소개한다. 고속 음향 복사력 임펄스 영상(acoustic radiation force impulse imaging; ARFI)으로 간과 비장에서 각각 세 번씩 전단파 속도를 반복 측정하고 복부 초음파 검사로 비장 길이를 측정한 자료에서 전단파 속도와 비장 길이 간의 상관 관계를 분석하기 위해 본 논문에서 소개한 방법들을 적용하였고 SAS의 PROC MIXED를 이용하는 방법을 제시하였다.

공간마케팅 관점에서 본 업사이클링 복합문화공간 특성에 관한 연구

한경화,장다정,남승희,황연숙 한국실내디자인학회 2023 한국실내디자인학회논문집 Vol.32 No.2

Both the global pandemic and technological advancements have driven patterns of consumer consumption online. As a result, companies find themselves needing to diversify their offline channels by offering customers unique experiences that go beyond a run-of-the-mill offering. One such strategy involves the use of upcycling spaces, which has multiple benefits: providing a distinctive customer experience, differentiation of a businesses from its competitors, and a more economical businesses. This study aims to analyze the upcycling of complex cultural spaces from a space marketing perspective to provide customers with an immersive experience. In Seongsu-dong, Seoul, eight former warehouse or industrial facilities that have been transformed into upcycled spaces were selected for the field survey. The spaces were evaluated based on five measures: economic feasibility, historicity, artistry, usability, and participation. The results showed that entertainment-oriented locations had a higher level of spatial composition compared to commercial-oriented locations, and that participation was highest and artistry the lowest across all measures. Although entertainment programs in the space added to the customer experience, there were generally a lack of programs that fully utilized the unique characteristics of the upcycled complex cultural space. The artistic aspect of utilizing existing industrial waste was also insufficient, which is likely, therefore, to limit the space’s uniqueness and desirability. Moreover, preserving the structure of existing spaces can serve as a form of storytelling, connecting the past and present, and appealing to modern consumers. Space marketing can be effectively utilized if it is developed with eco-friendly elements and incorporates the link between environmental

공간마케팅 전략적 요소를 적용한 가구 쇼룸 디자인에 관한 연구

한경화,황연숙 한국실내디자인학회 2023 한국실내디자인학회논문집 Vol.32 No.5

Due to recent improvements in income levels, cultural standards, and an increasing desire for an enhanced quality of life, consumer trends have shifted towards experience-centric consumption. At the same time, the furniture market is growing due to the diversification of lifestyles. Furniture showrooms, as offline spaces for displaying and selling furniture, need to develop competitive design strategies to stand out from other brands. Therefore, The purpose of this study is to analyze the design of furniture showrooms by deriving spatial marketing strategy elements, which can serve as basic data for competitive furniture showroom spaces that can meet consumer needs. The research extracted four strategic elements of space marketing: Spatial elements, Sensory elements, Narrative elements, and Relational elements, and developed a checklist based on these elements. The analysis focused on furniture showrooms of standalone brand furniture located in the metropolitan area. The findings of this study are as follows: In terms of space marketing, Spatial Elements were found to be the most prominent, with showrooms predominantly utilizing an open and inviting exterior to attract consumer interest from the outside. Relational Elements were the least emphasized, indicating a lack of programs aimed at enhancing consumer understanding of the brand and products and effectively conveying brand values and purpose.

분과발표 3 : 경도장애 학생들의 수학적 문제해결을 위한 폴리아의 전략 효과 연구

한경화,김영옥 한국수학교육학회 2016 수학교육 학술지 Vol.2016 No.1

우리나라 관개논에서 토양특성과 대형농기계를 사용한 경작년수에따른 여름 강우기 분산성 점토의 함량

한경화 한국환경농학회 2018 한국환경농학회지 Vol.37 No.4

BACKGROUND: This study was conducted to evaluate the water-dispersible clay content of paddy soils over the country in the summer rainy season as affected by cultivated years using heavy agro-machinery and soil properties such as texture and exchangeable sodium percentage. METHODS AND RESULTS: Water-dispersible clay content of 16 soil series of Korean paddy soils over the country were investigated in summer rainy season from July to August, 2006 by Middleton’s method. Waterdispersible clay content ranged from non-detected to 4.8%, showing maximum value from the fine textured soils and high clay dispersibility in average from the coarse textured soils. Longer cultivated years using agro-machinery more than 40 hp result in higer water-dispersible clay content for 60% of studied paddy soils with less than 5% of exchangeable sodium percentage (ESP). Exceptionally, soils with relatively big difference of ESP at about 10 percent showed higher water-dispersible clay content with higher ESP. CONCLUSION: Long years of cultivation using agromachinery with more than 40 hp enhanced waterdispersiblility of clay in approximately 60% of the studied paddy fields except for salt-affected soils.