• 한국농림기상학회:학술대회논문집
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• 한국농림기상학회 2013년도 추계 학술발표논문집
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• pp.30-31
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• 2013

Land use and land cover change (LULCC) due to human activities directly affects natural systems and contributes to changes in carbon exchange and climate through a range of feedbacks. How land use and land cover changes affect carbon exchanges can be assessed using multiyear measurement data from micrometeorological flux towers. The objective of the research is to assess the impact of land use and land cover change on carbon exchange in a heterogeneous cropland area. The heterogeneous cropland area in Haenam, South Korea is also subjected to a land conversion due to rural development. Therefore, the impact of the change in land utilization in this area on carbon exchange should be assessed to monitor the cycle of energy, water, and carbon dioxide between this key agricultural ecosystem and the atmosphere. We are currently conducting the research based on 10 years flux measurement data from Haenam Koflux site and examining the LULCC patterns in the same temporal scale to evaluate whether the LULCC in the surrounding site and the resulting heterogeneity (or diversity) have a significant impact on carbon exchange. Haenam cropland is located near the southwestern coast of the Korean Peninsula with land cover types consisting of scattered rice paddies and various croplands (seasonally cultivated crops). The LULCC will be identified and quantified using remote sensing satellite data and then analyzing the relationships between LULCC and flux footprint of $CO_2$ from tower flux measurement. We plan to calculate annual flux footprint climatology map from 2003 to 2012 from the 10 years flux observation database. Eventually, these results will be used to quantify how the system's effective performance and reserve capacity contribute to moving the system towards more sustainable configuration. Broader significance of this research is to understand the co-evolution of the Haenam agricultural ecosystem and its societal counterpart which are assumed to be self-organizing hierarchical open systems.

• 한국항만경제학회지
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• 제37권4호
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• pp.51-70
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• 2021

본 연구는 각 공항의 2018년 지속가능성 보고서를 바탕으로 21개 국제 공항의 환경 효율성을 측정하였다. 최근 다양한 산업 분야에서 환경 및 사회적 책임에 관심을 기울여왔는데, 특히 항공 분야의 경우 환경 친화적 및 지속가능성 운영에 관심을 보이는 선도적인 부문 중 하나이다. 그럼에도 불구하고, 공항의 환경적 운영에 관련된 연구는 경제적 또는 운영 효율성 연구에 비하면 매우 부족한 실정이다. 따라서 본 연구는 Directional Distance Function (DDF)의 활용을 통해 공항의 환경 비효율성에 대한 개선 여부를 알아보고, Data Envelopment Analysis (DEA)의 적용을 통해 운영 효율성을 측정하는 것을 목적으로 한다. 연구 결과, 주요 공항들은 설비를 효율적으로 운영하고 있으나, 그들 모두가 공항에서 배출되는 물질을 효율적으로 운영하지는 못했다. 게다가, 많은 공항은 여전히 잠재적으로 CO2와 물 소비량을 감소시킬 수 있는 개선의 여지가 존재하였다. 이를 통해 본 연구는 항공 분야에서 실행가능한 환경적 개선점을 제시하고자 하였다. 더 나아가서, 다른 산업 분야에서도 환경 효율성 개선을 위한 기준으로서 이 연구를 활용할 수 있을 것이다.

• 인간식물환경학회지
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• 제23권2호
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• pp.179-189
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• 2020

In order to increase the indoor air purification effect of plants, plants need to be placed on 5-10% of indoor spaces. To increase the density and utilization of plants in indoor spaces, studies on bio-wall, a vertical green wall system, have been recently conducted. The purpose of this study was to investigate the growth characteristics of 7 indoor plants introduced to the system and their rooting zones at different irrigation cycles. This study was conducted to investigate a proper irrigation cycle for the continuous maintenance of bio-wall systems. The conditions of their growth environment were maintained as follows: light intensity, 20-50 μmol·m^-2·s^-1 PPFD; and temperature, 20 - 25℃. For fertilization, Hyponex diluted with water at the ratio of 1:1,000 was supplied to plants. Irrigation was treated at intervals of 1, 3, 5, and 7 days for 1 hour at a time. As a result, there was no significant difference in the growth of plants between different irrigation cycles. Dieffenbachia 'Marianne' showed a significant decrease in the number of leaves at the irrigation cycle of 7 days. In addition, the chlorophyll content was relatively low at the irrigation cycle of 7 days. In terms of the color of leaves, a decrease in L value and b value and an increase in a value were observed, resulting in changes in brightness and color. Ardisia pusilla 'Variegata' showed a slightly higher photosynthetic activity and stomatal conductance when it was watered every day and once per 5 days, while Epipremnum aureum showed a relatively higher photosynthetic activity and stomatal conductance at the irrigation cycle of 3 days. In the case of root activity, it was found that the longer irrigation cycle, the higher root activity compared to daily irrigation. The development of roots of Peperomia clusiifolia was promoted by watering at long intervals. However, in the case of Aglaonema 'Siam-Aurora', the total number of roots decreased at the interval of 7 days. In conclusion, a proper irrigation cycle for the sustainable maintenance of vertical bio-wall systems seems to be 3 days.

• 산업융합연구
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• 제20권11호
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• pp.141-148
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• 2022

본 연구는 청장년층과 노년층의 고혈압 환자의 건강행위 수행정도를 파악하고, 이에 따른 복합만성질환으로의 이행과 합병증 발생을 예방하는데 유용한 기초자료를 얻기 위해 시도 되었다. 연구자료는 2018년 한국의료패널자료를 이용하여 분석하였다. 연구대상은 고혈압을 진단받은 자 중에서 장애 및 활동장애가 없는 3,117명이고 청장년층과 노년층으로 구분하여 분석하였다. 연구결과 첫째, 의료이용율과 약물복용 순응도는 전체적으로 높은 것으로 나타났으며, 노년층에서 더 높게 나타났다. 둘째, 체질량지수(BMI)평균 및 25kg/㎡ 이상 비만인 경우도 청장년층에서 더 높게 나타났다. 셋째, 흡연경험과 음주경험, 흡연량과 음주량은 모두 청장년층이 노년층에 비해 높은 것으로 나타났다. 넷째, 중등도 신체활동 및 걷기는 전체적으로 청장년층이 많이 실행하고, 중등도 신체활동량과 걷기 지속시간에는 차이가 없었다. 다섯째, 주관적 건강상태는 청장년층이 더 긍정적으로 인식하는 것으로 나타났다. 본 연구결과를 토대로 젊을때부터 맞춤형 건강관리의 필요성 인식제고와 지속가능한 실효성 있는 프로그램 개발이 이루어지도록 할 필요가 있다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2023년도 학술발표회
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• pp.179-179
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• 2023

This study suggests a new approach of water level forecasting for extended lead times using original data preprocessing with variational mode decomposition (VMD). Here, two machine learning algorithms including light gradient boosting machine (LGBM) and random forest (RF) were considered to incorporate extended lead times (i.e., 5, 10, 15, 20, 25, 30, 40, and 50 days) forecasting of water levels. At first, the original data at two water level stations (i.e., SW173 and SW269 in Bangladesh) and their decomposed data from VMD were prepared on antecedent lag times to analyze in the datasets of different lead times. Mean absolute error (MAE), root mean squared error (RMSE), and mean squared error (MSE) were used to evaluate the performance of the machine learning models in water level forecasting. As results, it represents that the errors were minimized when the decomposed datasets were considered to predict water levels, rather than the use of original data standalone. It was also noted that LGBM produced lower MAE, RMSE, and MSE values than RF, indicating better performance. For instance, at the SW173 station, LGBM outperformed RF in both decomposed and original data with MAE values of 0.511 and 1.566, compared to RF's MAE values of 0.719 and 1.644, respectively, in a 30-day lead time. The models' performance decreased with increasing lead time, as per the study findings. In summary, preprocessing original data and utilizing machine learning models with decomposed techniques have shown promising results for water level forecasting in higher lead times. It is expected that the approach of this study can assist water management authorities in taking precautionary measures based on forecasted water levels, which is crucial for sustainable water resource utilization.

• 한국초지학회:학술대회논문집
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• 한국초지조사료학회 2002년도 창립 30주년 International Symposium
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• pp.103-127
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• 2002

독일에서 초지를 근거로 한 가축경영의 중요한 문제는 목초보다는 옥수수나 곡류로 아주 쉽게 얻어질 수 있는 사료인 고에너지 농후사료가 필수적인 고능력우의 사육에 있다. 그러므로 우유생산은 초지지역에서 사료작물 지역으로 이동하는 추세이다. 아마 미래에는 우유생산은 초지지역에서 사료작물 지역으로 이동하는 추세이다. 아마 미래에는 우유생산에 있어서 농후사료에 의한 과잉영양분은 정부에 의해 제약을 받게 될 것이며, 발생되는 문제는 가장 좋은 초지를 이용하고, 최적의 사일리지 및 분료이용 기술을 이용하므로 해결될 수 있다. 지속적인 조사료 생산의 가장 중요한 단계는 특히, 사일리지 목초지에서 일반적인 보파기술을 포함한 초지관리에 있다. Hessian 초지의 약 40% 정도가 초지이용을 유지하기 위하여 그리고 자연자원을 보호하기 위하여 농업-환경 프로그램들(agri-environmental programs)로 관리를 받고 있다. 선택적인 조치들이 자연 및 산림보존에 대한 특별한 문제들을 해결하기 위하여 수행되어지고 있다.

• 자원리싸이클링
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• 제31권6호
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• pp.3-17
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• 2022

이산화탄소 배출량 및 에너지 사용이 많은 시멘트 산업은 탄소중립 실현 및 지속적인 발전을 위한 전략이 필요하다. 에너지 효율 향상을 위해 국내 대부분의 시멘트 업체에서 폐열 회수 시스템을 구축하여 전력을 생산하고 있으나, 이와 관련된 에너지 재활용 연구는 거의 없는 실정이다. 시멘트 생산이 많은 국가에서는 기존의 폐열 회수 시스템을 보완하기 위해 온도에 따라 적용하는 랭킨사이클 변경, 작동유체 비교, 2단 이상의 랭킨 사이클 적용 및 타 산업과의 연계 등을 통해 폐열 회수를 극대화하기 위한 연구를 수행하는 것으로 확인되었다. 본 연구에서는 국내외 시멘트 산업에서의 폐열 회수 및 활용에 대해 정리하여 에너지 효율 향상을 위해 필요한 연구 방향을 도출하고자 하였다.

• 농업과학연구
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• 제48권4호
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• pp.975-985
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• 2021

The sufficient amount of protein supply is crucial for improving the growth performance of growing beef cattle. In addition, due to the improvement in the genetic potential of the carcass weight of Hanwoo steers, dietary protein requirements may be increased during the rapid growth period. Accordingly, the dietary crude protein (CP) level in growing Hanwoo steers has been increasing in the field. However, little scientific evidence is available in relation to this. Therefore, this study was conducted to test whether a higher dietary CP level than convention would improve the growth performance and body metabolism in growing Hanwoo steers. Fifty growing Hanwoo steers were randomly divided into two groups and fed either a commercial diet (CON) or a higher CP (HCP) concentrate mix, provided with a similar level of dietary energy. Tall fescue hay was provided ad libitum. The dietary CP level did not affect growth performance and blood metabolite. Nitrogen intake, predicted nitrogen excretion, and retained nitrogen were higher in the HCP group than in the CON group (p < 0.01). Although there was no difference in the nitrogen utilization efficiency, the growth efficiency per retained nitrogen decreased in the HCP group (p = 0.02). A higher dietary CP level may increase nitrogen retention in growing Hanwoo steers without improving growth performance, which leads to reduced growth efficiency per retained nitrogen. Furthermore, considering the high price of feed protein and increased nitrogen excretion to the environment, a further increase in the protein level may not be sustainable.

• 한국환경과학회:학술대회논문집
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• 한국환경과학회 2019년도 정기학술대회 발표논문집
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• pp.134-134
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• 2019

Utilization of organic waste as a renewable energy source is promising for sustainability and mitigation of climate change. Pyrolysis converts organic waste to gas, oil, and biochar by incomplete biomass combustion. Biochar is widely used as a soil conditioner and adsorbent. Biochar adsorbs/desorbs metals and ions depending on the soil environment and condition to act as a nutrient buffer in soils. Biochar is also regarded as a carbon storage by fixation of organic carbon. Phosphorus (P) and nitrogen (N) are strictly controlled in many wastewater treatment plants because it causes eutrophication in water bodies. P and N is removed by biological and chemical methods in wastewater treatment plants and transferred to sludge for disposal. On the other hand, P is an irreplaceable essential element for all living organisms and its resource (phosphate rock) is estimated about 100 years of economical mining. Therefore, P and N recovery from waste and wastewater is a critical issue for sustainable human society. For the purpose, intensive researches have been carried out to remove and recover P and N from waste and wastewater. Previous studies have shown that biochars can adsorb and desorbed phosphates implying that biochars could be a complementary fertilizer. However, most of the conventional biochar have limited capacity to adsorb phosphates and nitrate. Recent studies have focused on biochar impregnated with metal salts to improve phosphates and nitrate adsorption by synthesizing biochars with novel structures and surface properties. Metal salts and metal oxides have been used for the surface modification of biochars. If P removal is the only concern, P adsorption kinetics and capacity are the only important factors. If both of P and N removal and the application of recovery are concerned, however, P and N desorption characteristics and bioavailability are also critical factors to be considered. Most of the researches on impregnated biochars have focused on P removal efficiency and kinetics. In this study, coffee waste is thermally treated to produce biochar and it was impregnated with Mg/Al to enhance phosphates and nitrate adsorption/desorption and P bioavailability to increase its value as a fertilizer. Kinetics of phosphates and nitrate adsorption/desorption and bioavailability analysis were carried out to estimate its potential as a P and N removal adsorbent in wasewater and a fertilizer in soil.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2022년도 추계학술대회
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• pp.577-579
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• 2022

그동안 행해진 중앙 집중형의 지식 창고(Knowledge Repository)에 분산된 지식을 모으는 방식만으로는 개인의 역량 및 조직의 경쟁력 강화라는 지식 관리의 본질적 목표에 달성하기 어렵다. 지속가능한 지식 생태계를 구축하기 위해서는 독립적인 지식 생산이 아닌 교류와 협력을 통한 지식 생산으로 확대되어야 하며, 이를 통해 유의미하고 고부가가치의 지식 자원을 생산할 수 있어야 한다. 이에 본 연구는 과학기술 지식자원을 저장하고 개방·공유·활용을 통해 지식을 재생산하고 진화시키는 통합서비스 플랫폼을 설계하는 것을 목표로 한다. 설계된 플랫폼은 그 우수성을 평가하기 위해, 계획 수립의 적정성, 플랫폼의 효과성, 플랫폼의 효율성, 로드맵의 적정성 항목들로 분류된 세부 항목들에 대해 평가를 수행하였으며, 상기 4개 평가 항목에 대해 평균 95.56점을 받았다.