• Korean Journal of Agricultural and Forest Meteorology
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• v.2 no.4
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• pp.175-182
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• 2000

Spatial interpolation of daily temperature forecasts and observations issued by public weather services is frequently required to make them applicable to agricultural activities and modeling tasks. In contrast to the long term averages like monthly normals, terrain effects are not considered in most spatial interpolations for short term temperatures. This may cause erroneous results in mountainous regions where the observation network hardly covers full features of the complicated terrain. We developed a spatial interpolation model for daily minimum temperature which combines inverse distance squared weighting and elevation difference correction. This model uses a time dependent function for 'mountain slope lapse rate', which can be derived from regression analyses of the station observations with respect to the geographical and topographical features of the surroundings including the station elevation. We applied this model to interpolation of daily minimum temperature over the mountainous Korean Peninsula using 63 standard weather station data. For the first step, a primitive temperature surface was interpolated by inverse distance squared weighting of the 63 point data. Next, a virtual elevation surface was reconstructed by spatially interpolating the 63 station elevation data and subtracted from the elevation surface of a digital elevation model with 1 km grid spacing to obtain the elevation difference at each grid cell. Final estimates of daily minimum temperature at all the grid cells were obtained by applying the calculated daily lapse rate to the elevation difference and adjusting the inverse distance weighted estimates. Independent, measured data sets from 267 automated weather station locations were used to calculate the estimation errors on 12 dates, randomly selected one for each month in 1999. Analysis of 3 terms of estimation errors (mean error, mean absolute error, and root mean squared error) indicates a substantial improvement over the inverse distance squared weighting.

• Journal of the Korean Wood Science and Technology
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• v.42 no.3
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• pp.309-317
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• 2014

Harvested wood products (HWP) are known as products from the tree such as sawn wood, plywood, particle board, structural lumber, wooden interior material, wooden furniture, and paper products. Because carbon is locked up in the HWP until eventual end-use of HWP, HWP played a role as the carbon storage which has the effect of stabilizing the concentration of carbon dioxide in the atmosphere. For these reasons, the suggestion that it must admit the carbon storage effect of HWP has been constantly raised. In 2011, the 17th session of the Conference of the Parties (COP) to the United Nations Framework Convention on Climate Change (UNFCCC) which was held in Durban, South Africa, assigned "Production Approach" which targets only the HWP producted by using round wood of domestic forestry as a official method for carbon accounting. Therefore, it is necessary that each country has to determine the half-life of wood in order to correspond to the discussions and negotiations between countries in the future and to develop an inventory of product-specific domestic wood. In this study, some countries' examples of the methods and conditions for determining half-life of HWP were investigated, and it was tried to derive the factor and methodology to determine half-life span of domestic HWP appropriately.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.461-461
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• 2016

이상기후로 인하여 제방붕괴에 대한 위험성이 높아지고 있고, 이로 인해 발생하는 제내지 내 붕괴 홍수파에 대한 연구가 증가하고 있다. 특히 홍수파 선단의 이동 속도 추정은 제내지의 위험성을 예측하고, EAP 등을 수립하는데 매우 중요한 자료가 될 수 있다. 제내지에서의 선단 홍수파에 대한 예측을 하기 위해서는 해당 지역의 하천특성, 수리특성 및 제방 등 수공구조물 특성뿐만 아니라, 제내지의 지형 및 토지이용 현황 등을 조사하여 수리실험이나 수치모의를 수행해야 하는 것이 일반적이다. 수치해석의 경우 수리실험에 비하여 경제성 및 효율성 측면에서 뛰어날 수 있으나, 제방 붕괴과정 및 메커니즘을 반영하기가 불가능하다. 이에 반해 수리모형실험의 경우 제방붕괴 양상 및 그 과정의 재현이 가능하기 때문에, 제내지에서의 선단홍수파 전파에 관한 보다 정확한 양상을 파악할 수 있을 것이다. 그러나 이러한 실험은 실제 크기의 하천이 아닌 축소모형 또는 개수로에서 수행되었기 때문에, 초기 홍수파의 전파가 축척효과(Scale effect)의 영향을 받을 가능성이 매우 크다. 특히 선단 홍수파의 경우 파가 진행되면서 수심이 낮아지고, 유속이 느려지기 때문에 그 영향은 점차 증대된다고 할 수 있다. 이에 본 연구에서는 이러한 초기 선단 홍수파의 표면장력 영향을 고려한 보정 계수 산정에 대한 연구를 수리실험을 통해 수행하였다. 연구는 크게 4가지 과정으로 구성되었다. 첫째는 농도-표면장력의 관계 규명이며, 둘째는 표면장력-홍수파 전파 속도 관계 규명이다. 셋째는 표면장력과 Weber Number(We)의 관계를 도출하는 것이며, 마지막은 We를 이용하여 한계조건을 제시하는 것이다. 실험은 계면활성제의 농도를 변화시켜가며, 얇은 유리관(D=1.0 mm)에서 물의 상승 높이 및 접촉각을 측정하여 농도와 표면장력의 관계를 측정하였으며, 이러한 결과를 바탕으로 물의 표면장력을 변화시켜 가며 $0.5(B){\times}0.3(L){\times}0.2(H)m$의 Head-tank에 설치된 수문을 빠르게 개방하여, 홍수파가 퍼지는 양상을 관측하였다. 홍수파의 이동 속도는 진행시간에 따라서 퍼짐 넓이를 측정하여 제곱근을 취하는 방식으로 평균속도를 산정하였다. 이러한 관계를 이용하여 표면장력이 없을 경우의 이동속도 및 ??를 도출하였다. 본 연구를 통해 홍수파 전파 특성에 대한 수리실험 자료를 바탕으로 Weber 수를 도출하여 표면장력의 영향을 받는지 여부를 판단할 수 있으며, 표면장력의 영향을 받을 경우, 제시된 결과를 이용하여 홍수파 선단의 속도를 보정할 수 있다. 본 연구 결과는 토대로 축소모형으로 수행되는 홍수파 전파에 대한 수리실험결과의 보정 기초자료로 매우 유용할 것으로 판단된다.

• Journal of the Korean earth science society
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• v.40 no.2
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• pp.109-118
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• 2019

Cloud-aerosol interactions are considered to be one of the most important forcing mechanisms in the climate system. However, there is considerable disagreement on the magnitude and even on the sign of how aerosol perturbations affect cloud fraction and lifetime. Furthermore, aerosol effects on clouds and precipitation are not readily separable from the effects of meteorology. This review paper summarizes the study of precipitation susceptibility $S_o$, which qualifies how aerosol perturbations alter the magnitude of the precipitation rate (R) while minimizing the effects of macrophysical factors such as cloud depth (H) and liquid water path (LWP). The analysis shows that the precipitation susceptibility $S_o$ for the warm marine boundary layer clouds is insensitive to aerosol perturbations at low LWP (equivalently low H). However, R decreases as aerosols increase at intermediate LWP. This is because aerosols act as cloud seed and produce numerous small-sized particles, which impede the collision and coalescence process that leads to precipitation. At high LWP, $S_o$ decreases with increasing LWP as there are enough water contents in the clouds. The LWP or H dependent $S_o$ behavior differs depending on the predominant cloud physics processes in the clouds.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.6
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• pp.521-530
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• 2019

With a view to respond to urban climate change issues and improve the urban environment in a qualitative manner, the strategy of multi-dimensional greening of the traditional markets in the City of Seoul to secure the multi-dimensional green spaces can result in a significant effect in terms of landscaping, environment, and spatial aspect. The purpose of this study is to examine the elements of multi-dimensional greening for the multi-dimensional greening of buildings in order to enhance the greening function within urban phenomena and, with this, establish the criteria for success introduction of multi-dimensional greening and its qualitative expansion. For this, a total of 569 consumers of traditional markets have been interviewed, and the data from their questionnaires were analyzed through SPSS and AMOS software. The result of the analysis showed that the elements of the multi-dimensional greening of traditional markets, such as the economical, physical, functional, visual, and facility aspects all affected the consumer expectation in a positive manner. Also, depending on the gender of the customers of traditional markets, the ecological aspect among the elements of multi-dimensional greening had a significant difference. And, by the age, the functional, physical, and visual aspects of the elements of multi-dimensional greening showed a significant different. And, the expectation on the multidimensional greening of traditional markets also showed a statistically significant difference. By the level of education, there were significant differences in terms of the physical and visual aspects of the multi-dimensional greening elements. And, the level of expectation on the multidimensional greening also differed significantly.

• Journal of Korea Water Resources Association
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• v.52 no.3
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• pp.187-194
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• 2019

Intake ratio from river constitutes about 31% (8/26) that beings to "water stress country" as "Medium ~ High" with China, India, Italy, South Africa, etc. Therefore, the present study on a dam that is the most effective and direct for securing water resources has been performed. First of all, climate change scenarios were investigated and analyzed. RCP 4.5 and 8.5 with 12.5 km grid resolution presented in the IPCC (Intergovernmental Panel on Climate Change) 5th Assessment Report (AR5) were applied to study watershed using SWAT (Soil and Water Assessment Tool) and HEC-ResSim models that carried out co-operation. Based on the results of dam simulation, the reduction effects of floods and droughts were quantitatively presented. The procedures of dam projects of the USA, Japan and Korea were investigated. As a result, there are no estimating quantitative criteria, calculating methods or formulas. In the present study, therefore, indexes for selecting suitable dam site through literature investigation and analyzing dam watersheds were determined, Expert questionnaire for various indexes were performed. Based on the above mentioned investigation and expert questionnaire, a methodology assigning weight using AHP method were proposed. The function of suitable dam (FSDS) site was calibrated and verified for four medium-sized watersheds. Finally, automated model for suitable dam site was developed using FSDS and 'Model builder' of GIS tool.

• Journal of Korean Society of Disaster and Security
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• v.14 no.3
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• pp.1-16
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• 2021

Recently, large-scale projects are required in the water resources sector considering safety and publicitythe due to uncertainty of securing water resources and changes in the ecological environment by climate change. Among these large-scale projects, the projects that fall under the preliminary feasibility study are determined by comprehensive analysis based on economic analysis, policy analysis, and balanced regional development analysis. However, most of the results of the preliminary feasibility study showed a tendency to depend heavily on economic analysis. For this reason, projects in non-metropolitan areas sometimes fail in the preliminary feasibility study. To supplement this point, the Korea Development Institute revised the standard guidelines for preliminary feasibility studies for water resources sector projects that place a high weight on policy feasibility analysis. Therefore, the objective of this study is to analyze the cases of the preliminary feasibility study conducted previously and to suggest the direction of policy analysis in the preliminary feasibility study for water resources sector projects. For this, we analyze preliminary feasibility studies conducted for 18 years from 2002 to 2019, and suggest direction of policy analysis method using the benefit items not included in the economic analysis.

• Journal of Life Science
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• v.30 no.12
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• pp.1128-1139
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• 2020

Over recent years, it has become evident that food and agricultural products are easily contaminated by fungi of Aspergillus, Fusarium, and Penicillium due to rapid climate change, which is not only a global food quality concern but also a serious health concern. Owing to consumers' interest in health, resistance to preservatives such as propionic acid and sorbic acid (which have been used in the past) is increasing, so it is necessary to develop a substitute from natural materials. In this review, the role of lactic acid bacteria as a biological method for controlling the growth and toxin production of fungi was examined. According to recent studies, lactic acid bacteria effectively inhibit the growth of fungi through various metabolites such as organic acids with low molecular weight, reuterin, proteinaceous compounds, hydroxy fatty acids, and phenol compounds. Lactic acid bacteria effectively reduced mycotoxin production by fungi via adsorption of mycotoxin with lactic acid bacteria cell surface components, degradation of fungal mycotoxin, and inhibition of mycotoxin production. Lactic acid bacteria could be regarded as a potential anti-fungal and anti-mycotoxigenic material in the prevention of fungal contamination of food and agricultural products because lactic acid bacteria produce various kinds of potent metabolic compounds with anti-fungal activities.

• Journal of Korean Society of Forest Science
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• v.100 no.3
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• pp.315-326
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• 2011

In recent years, domestic and international interests focus on climate change, and importance of forest as carbon sink have been also increased. Particularly REDD+ mechanism expanded from REDD (Reduced Emissions from Deforestation and Degradation) is expected to perform a new mechanism for reducing greenhouse gas in post 2012. To conduct this mechanism, countries which try to get a carbon credit have to certify effectiveness of their activities by MRV (Measuring, Reporting and Verification) system. This study analyzed the approaches for detecting land cover change and estimating carbon stock by remote sensing technology which is considered as the effective method to develop MRV system. The most appropriate remote sensing for detection of land cover change is optical medium resolution sensors and satellite SAR (Synthetic Aperture Radar) according to cost efficiency and uncertainty assessment. In case of estimating carbon stock, integration of low uncertainty techniques, airborne LiDAR (Light Detection and Ranging), SAR, and cost efficient techniques, optical medium resolution sensors and satellite SAR, could be more appropriate. However, due to absence of certificate authority, guideline, and standard of uncertainty, we should pay continuously our attention on international information flow and establish appropriate methods. Moreover, to apply monitoring system to developing countries, close collaboration and monitoring method reflected characteristics of each countries should be considered.

• Journal of Internet of Things and Convergence
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• v.8 no.2
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• pp.35-40
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• 2022

In the agricultural environment, pesticide control requires a high risk of work and a high labor force for farmers. The effectiveness of pesticide control using unmanned aerial vehicles varies according to climate, land type, and characteristics of unmanned aerial vehicles. Therefore, an effective method for pesticide control by unmanned aerial vehicles considering the spraying conditions and environmental conditions is required. In this paper, we propose an efficient pesticide control system based on agricultural unmanned aerial vehicles considering the application conditions and environmental information for each crop. The effectiveness of the proposed model was demonstrated by measuring the drop uniformity of pesticides according to the change in altitude and speed after attaching the sensory paper and measuring the penetration rate of the drug inside the canopy according to the change in crop growth conditions. Experiment result, the closer the height of the UAV is to the ground, the more evenly the crops are sprayed, but for safety reasons, 2m more is suitable, and on average a speed of 2m/s is most suitable for control. The proposed control system is expected to help develop intelligent services based on the use of various unmanned aerial vehicles in agricultural environments.