• Atmosphere
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• v.32 no.4
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• pp.395-409
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• 2022

A new soil moisture initialization scheme is applied to the Korea Meteorological Administration (KMA) Global Seasonal forecasting system version 6 (GloSea6). It is designed to ingest the microwave soil moisture retrievals from Soil Moisture Active Passive (SMAP) radiometer using the Local Ensemble Transform Kalman Filter (LETKF). In this technical note, we describe the procedure of the newly-adopted initialization scheme, the change of soil moisture states by assimilation, and the forecast skill differences for the surface temperature and precipitation by GloSea6 simulation from two preliminary experiments. Based on a 4-year analysis experiment, the soil moisture from the land-surface model of current operational GloSea6 is found to be drier generally comparing to SMAP observation. LETKF data assimilation shows a tendency toward being wet globally, especially in arid area such as deserts and Tibetan Plateau. Also, it increases soil moisture analysis increments in most soil levels of wetness in land than current operation. The other experiment of GloSea6 forecast with application of the new initialization system for the heat wave case in 2020 summer shows that the memory of soil moisture anomalies obtained by the new initialization system is persistent throughout the entire forecast period of three months. However, averaged forecast improvements are not substantial and mixed over Eurasia during the period of forecast: forecast skill for the precipitation improved slightly but for the surface air temperature rather degraded. Our preliminary results suggest that additional elaborate developments in the soil moisture initialization are still required to improve overall forecast skills.

• Advances in Computational Design
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• v.7 no.4
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• pp.321-343
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• 2022

Museum buildings display artefacts for public education and enjoyment, ensuring their long-term safety and the comfort of visitors by following strict indoor environment control protocols using mechanical Heating, Ventilation and Air Conditioning (HVAC) systems to keep the (environmental) variables at a fixed comfort level. Maintaining this requires constant supply of energy currently mostly sourced from the combustion of fossil fuels which exacerbates climate change. However, a review on the effects of the indoor environmental variables on museum artefacts as well as museum visitors revealed that there is no specific point at which artefact deterioration occurs, and that there are wide ranges of conditions that guarantee the long-term safety of artefacts and human comfort. Visits to museum buildings in hot-humid tropical climate of Nigeria revealed that strict indoor environmental practices were adopted. Even when appropriate micro-climatic conditions are provided for artefacts, mechanical HVAC systems remain necessary for visitor comfort because almost no consideration is given to natural ventilation. With the current global push towards energy management, this paper reviewed passive environmental control practices, architectural design strategies, and discusses the adaptation of double skin façade with jali screens, and the notion of smart materials, which can satisfy the range of requirements for the long-term safety of artefacts and levels of human comfort in buildings in hot-humid tropical climate, without mechanical HVAC systems. This review would inspire more discussions on passive, energy efficient, smart and climate responsible popular architecture, challenging current thinking on the impact of the more accepted representative architecture.

• Korean Journal of Ecology and Environment
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• v.52 no.1
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• pp.21-27
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• 2019

Analysis of water quality distribution is very important for river water quality management. Recently, various studies have been conducted on the analysis of water quality distribution according to reduction methods of nonpoint pollutant. The objective of this study was to select the probability distributions of water quality constituents (T-N, T-P, COD, SS) according to the farming forms (control, slow release fertilizer, water depth control) during non-storm period in the paddy fields. The field monitoring was conducted monitoring site located in Baeksan-myun, Buan-gun, Jeollabuk-do, Korea during non-storm period from May to September in 2016. Our results showed that there were no differences in water quality among three different farming forms, except for SS of control and water depth control. K-S method was used to analyzed the probability distributions of T-N, T-P, COD and SS concentrations discharged from paddy fields. As a results of the fitness analysis, T-N was not suitable for the normal probability distribution in the slow release fertilizer treatment, and the log-normal probability distribution was not suitable for the T-P in control treatment. The gamma probability distribution showed that T-N and T-P in control and slow release fertilizer treatment were not suitable. The Weibull probability distribution was found to be suitable for all water quality constituents of control, slow release fertilizer, and water depth control treatments. However, our results presented some differences from previous studies. Therefore, it is necessary to analyze the characteristics of pollutants flowing out in difference periods according to various farming types. The result of this study can help to understand the water quality characteristics of the river.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.695-700
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• 2009

Maintaining an IAQ with fresh in school building is very important because the good IAQ can be possible to improve the academic performance. Since school buildings are very dense and require a lot of fresh air, the need for ERV(Energy Recovery Ventilator) has become obvious. While opening a window does provide ventilation, the building's heat and humidity will then be lost in the winter and gained in the summer, both of which are undesirable for the indoor climate and for energy efficiency. ERV technology offers an optimal solution: fresh air, better climate control and energy efficiency. However, when the outdoor air condition is favorable to control the indoor environment such as spring and autum in Korea, heat exchange in ERV would rather increase the cooling load than diminish. Economizer cycle control which using the outdoor air in controlling the indoor thermal environment has many benefit in terms of energy saving and IAQ control. In this study, the ERV with economizer cycle control will be suggested. And then the system control characteristics and energy saving effect will be analyzed through the TRSNSYS Simulation.

• Korean Journal of Environmental Biology
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• v.37 no.4
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• pp.682-689
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• 2019

The Korean flowering cherry is a popular tree. However, the trees have started to defoliate early, including those in Gurye. Thus, it is necessary to identify the causes of the early defoliation and how to manage them. Therefore, the purpose of this study was threefold: 1) to investigate the early defoliation of flowering cherry trees, 2) to identify the differences in growth and flowering of the trees in response to treatment, and 3) to suggest an optimal treatment for the trees. The experiment was conducted in Gurye at a site 3km long with 102 flowering cherry trees along a street. There were three treatments: control, an environmentally friendly insecticide and a disinfectant(treatment 1), and an environmentally friendly insecticide, a disinfectant, and irrigation (treatment 2). The trees in Gurye were compared to trees on Jeju Island. The defoliation rates of the flowering cherry in Gurye were significantly higher than those on Jeju Island at each measurement time. Within Gurye, the defoliation rate was significantly higher in the trees of the control than in the two treatments and only the trees in the control from Gurye had shot-hole disease. Post-treatment, twigs collected from the control during April showed significantly poorer growth, lower numbers of flowering buds per twig, and lower numbers of foliar buds. The trees given treatment 1 showed significantly greater growth, number of total buds, flowering buds per twig, and density of buds than the trees given treatment 2. After analyzing the correlations, it was established that early defoliation led to poorer growth, affecting the flowering of the trees.

• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.75-76
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• 2012

본 논문에서는 고속 운전을 위하여 IPMSM(Interior Permanent Magnet Synchronous Motor)의 약계자 운전을 제시한다. IPMSM 운전을 위한 약계자 제어기는 SMO(Sliding Mode Observer)를 통한 추정 속도와 실제 전동기의 속도를 비교하여 나타나는 오차값을 피드백 받아서 이용한다. 기본적으로 속도 오차가 없는 상황에서는 MTPA(Maximum Torque Per Amp.)에서 동작 시키고 속도 오차가 증가하면 이 오차에 대해 d축 전류를 음의 방향으로 증가시켜 약계자 제어를 한다. 본 논문에서는 제시한 약계자 운전으로 IPMSM에 적용시험을 한다. 그리고 시험결과를 분석하여 본 논문의 타당성을 입증한다.

• The Korean Journal of Pesticide Science
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• v.20 no.2
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• pp.145-151
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• 2016

This study was carried out to develop the economic thresholds for powdery mildew on eggplant. To investigate the relationship between powdery mildew incidence degree and yield, experimental plots with ten treatments as the initial disease degree were established. Disease severity exhibited negative and significant correlation with fruit weight and number of fruit. There existed close correlation between rate of diseased leaf area and yields in the greenhouse (control with fungicide Y = -36.5X+2938.5 $R^2=0.91$ $r=-0.913^*$, no fungicide: Y = -29.57X+2574.4 $R^2=0.73$ $r=-0.858^*$). There existed close correlation between rate of diseased leaf area and yield loss in the greenhouse (Y = 1.27X-2.4 $R^2=0.88$ $r=0.91^*$). The economic thresholds for powdery mildew on eggplant was below 14.7% rate of diseased leaf area per plant in the greenhouse.

• Journal of Bio-Environment Control
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• v.22 no.2
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• pp.131-137
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• 2013

This study was conducted to develop new indoor plants and to investigate the effects of light intensity on the growth of Trachelospermum asiaticum var. intermedium Nakai and Piper kauzura. Most of T. asiaticum var. intermedium Nakai under 100 lux light intensity were blighted in two months, whereas survival rate was 83.3% after five months under 1,000 lux and 2,500 lux. Plant height, number of leaf, leaf width and leaf length increased as light intensity increased. The plants maintained under 2,500 lux showed the greatest plant height and leaf number. Piper kadzura Ohwi was defoliated and blighted in four months under 100 lux light intensity, whereas survival rate was 100% after five months under 1,000 lux and 2,500 lux. But, 1,000 lux light intensity was more favorable chlorophyll contents, leaf length and leaf width than 2,500 lux light intensity. Slight increase of chlorophyll contents and leaf growth under 1,000 lux indicates that Piper kadzura Ohwi could be utilized highly as a indoor ornamental plant.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.27 no.2
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• pp.43-53
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• 2024

This study attempted to elucidate the ecological niches and influencing environmental factors of Quercus variabilis and Quercus acutissima, which are representative deciduous broad-leaved trees in Korean forests, taxonomically close and genetically similar, under climate change conditions. Under climate change conditions induced by increased CO₂ and temperature, soil moisture and nutrient environments were manipulated in four gradients. At the end of the growing, plants were harvested to measure growth responses, calculate ecological niches, and compare them with those of the control. Eperimental plants were grown for 180 days in a glass greenhouse designed with four gradients each for soil moisture and nutrient environments under climate change conditions induced by increased CO₂ and temperature. After harvesting, growth responses of leaf traits were measured, ecological niches were calculated, and these were compared with those of the control groups. Furthermore, the responses of the two species' populations were interpreted using principal component analysis(PCA) based on leaf trait measurements. As a result, under climate change conditions, the ecological niche breadth for moisture environment was broader for Quercus variabilis than Quercus acutissima, whereas for the nutrient environment, Quercus acutissima exhibited a broader niche breadth than Quercus variabilis. And the rate of change in ecological niche breadth due to climate change decreased for Quercus variabilis in both moisture and nutrient environments, while for Quercus acutissima, it increased in the moisture environment but decreased in the nutrient environment. Additionally, in terms of group responses, both Quercus variabilis and Quercus acutissima expanded their ecological niches under climate change conditions in both soil moisture and nutrient conditions, with Quercus acutissima exhibiting a broader niche than Quercus variabilis under nutrient conditions. These results indicate that the changes in leaf morphological characteristics and the responses of individuals reflecting them vary not only under climate change conditions but also depending on environmental factors.

• Environmental Engineering Research
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• v.22 no.4
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• pp.393-400
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• 2017

One of the big problems facing municipalities is the management and control of urban flooding where urban drainage systems are under growing pressure due to increases in urbanization, population and changes in the climate. Urban flooding causes environmental and infrastructure damage, especially to roads, this damage increasing maintenance costs. The aim of the present study is to develop a decision support tool to identify the performance of storm networks to address future risks associated with climate change in the Middle East region and specifically, illegal sewer connections in the storm networks of Karbala city, Iraq. The storm water management model has been used to simulate Karbala's storm drainage network using continuous hourly rainfall intensity data from 2008 to 2016. The results indicate that the system is sufficient as designed before consideration of extra sewage due to an illegal sewer connection. Due to climate changes in recent years, rainfall intensity has increased reaching 33.54 mm/h, this change led to flooding in 47% of manholes. Illegal sewage will increase flooding in the storm system at this rainfall intensity from between 39% to 52%.