• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.11a
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• pp.65-70
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• 2007

고연색성의 실시간으로 색온도 제어 가능한 승강기용 조명 제품 개발을 위하여 4계절 별 일 중 주광의 색온도 변화를 계산하였다. 4계절 별 일 중의 색온도 변화는 대한민국 서울의 위치를 기준으로 태양광 직사조도, 청공광조도 등을 계산하고 지면조도와 색온도의 관계로부터 춘분, 하지, 추분, 동지의 일 중 색온도 변화를 계산하였다. 이 값들을 색온도 제어회로의 Microprocessor에 이식함으로 4계절 별로 실시간으로 색온도가 변화하는 승강기용 조명기구를 개발하였다. 또한 개발 시제품의 전기적, 광학적 성능 측정 결과 각각의 개발 목표 항목을 만족시켰다.

• Journal of the Korean earth science society
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• v.27 no.2
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• pp.149-158
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• 2006

This study analyzes the seasonality precipitation using precipitation data from 1973 to 2001 over South Korea. The Seasonality Index and Annual variation of the Seasonality Precipitation were investigated from sixty-three observation stations. The Seasonality Precipitation means the degree of the precipitation falling intensively for some specific months. Spatially, precipitation that has a strong characteristic of regional shower is defined as seasonal precipitation. Precipitation forms are changed with various reasons and mainly the sporadic and local shower precipitation after rain spell in summer. Especially there appears a tendency that this kind of precipitation is sharply increasing in 1990's. Seasonality Index is used as a method to understand seasonal precipitation. If the yearly rainfall is concentrated for some specific months, Seasonality Index is growing gradually. It is confirmed that there is a tendency that all the from sixty-two observation stations Seasonality Index. While Seasonality Index over South of Korea concentrated from June to August because of the summer rain spell in the past ($1973{\sim}1982$), there appears to be a tendency that it concentrated from August and September since the mid 1990's. From the analysis of seasonal precipitation intensity distribution, most of southern Korea is under seasonality precipitation intensity 4. The seasonality precipitation intensity classification results are as follow: most of the observation stations were on a scale intensity of 3 and 4 in the past but currently reads seasonality precipitation intensities of 5 and 6.

• Journal of Wetlands Research
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• v.17 no.3
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• pp.311-319
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• 2015

The Korean government has made progress in its project for sewage distribution in rural areas to ensure the balanced development of the country and its water conservation system. The project for sewage distribution in rural areas was analyzed with the yearly operational results of municipal wastewater treatment plant (MWTP). The sewage characteristics of the MWTP in a rural area changed according to seasonal variations, and the lowest pollution concentrations were obtained in the summer. The treatment efficiency of nutrients in the biological treatment process changed slightly more than the treatment efficiency of organic compounds, and the lowest treatment efficiency was obtained in winter. In addition, the relationship between treatment efficiency and retention time and F/M ratio showed similar results despite seasonal variations. It was considered that sewage characteristics and treatment efficiency changed according to seasonal variations when the treatment process was selected in MWTPs in rural areas. Especially, Maintenance of MWPT is need for the stable treatment efficiency of nutrients in the winter.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.20 no.4
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• pp.372-389
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• 2008

In this study, we formed a detailed grid at the estuary area of the Nakdong and collected the surface sediments. Particle size analysis and comparison with existing data were conducted to investigate the characteristics of seasonal and long-term changes in the sediments. As a result of investigation, the distribution of the sediments showed a great change per season and was greatly influenced by the quantity of outfall discharge at the Nakdong estuary barrier and the incident wave climate. The sandy sediments showed dominant movement toward the front of Jinwoodo west of the estuary area of the Nakdong due to the influence of the ENE wave, the annually-dominant wave. And the muddy sediments showed deposition by being moved toward the deep open sea along with a current. The present conditions of the sediments at the estuary area of the Nakdong showed great differences from the results of previous studies.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.6
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• pp.557-565
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• 1984

The year-to-year fluctuations of seasonal variation of sea surface temperatures (SST) in the Korea Strait are studied based on monthly SST data for more than 50 years at Mitsushima ana Okinoshima in the strait. The frequency distribution of SST has two peaks at temperatures below and above the multi-year average, but that of SST anomalies has only one peak at the zero anomaly. More than $95\%$ of the anomalies are in the range of ${\pm}2^{\circ}C$. The harmonic constansts of seasonal SST variation vary from year to year. The standard deviations of annual means, annual amplitudes, ana semi-annual amplitudes are less than $1^{\circ}C$, and those of the annual ana semi-annual phases are about $5^{\circ}$ and less than $50^{\circ}$, respectively. The SST in the Korea Strait have a tendency to decrease their amplitudes as the annual means increase. Physical mechanisms responsible for the analyzed results are discussed in this paper.

• Ecology and Resilient Infrastructure
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• v.10 no.4
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• pp.226-236
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• 2023

As climate change intensifies, the importance of studying plant phenology has increased, leading to a surge in research employing automated video recording devices like Phenocams. In this study, using the Phenocams operated by the National Institute of Ecology, we examined the trends in plant phenological changes across diverse ecosystem types in South Korea and analyzed their correlations with climate factors. The patterns of plant phenological changes varied by region and tree species. Pinus thunbergii and Pinus densiflora typically show an overall increase in their growth period, positively correlating with temperatures and precipitation during winter. However, uniquely, for Abies koreana on Hallasan Mt., a higher amount of precipitation in August leads to an earlier end of season (eos), and the correlation analysis with the recent phenomenon of dying A. Koreana seems necessary. beyond the analysis, solutions for handling missing data issues during the data collection process were proposed. Furthermore, to expand future research scope and encompass diverse ecosystem types, a suggestion to combine Phenocam research with satellite observations was presented.

• Journal of Korean Society of Forest Science
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• v.109 no.4
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• pp.361-370
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• 2020

Long-term observation of the life cycle of plants allows the identification of critical signals of the effects of climate change on plants. Indeed, plant phenology is the simplest approach to detect climate change. Observation of seasonal changes in plants using digital repeat imaging helps in overcoming the limitations of both traditional methods and satellite remote sensing. In this study, we demonstrate the utility of camera-based repeat digital imaging in this context. We observed the biological events of plants and quantified their phenophases in the northern temperate type deciduous broadleaf forest of Jeombong Mountain. This study aimed to identify trends in seasonal characteristics of Quercus mongolica (deciduous broadleaf forest) and Pinus densiflora (evergreen coniferous forest). The vegetation index, green chromatic coordinate (GCC), was calculated from the RGB channel image data. The magnitude of the GCC amplitude was smaller in the evergreen coniferous forest than in the deciduous forest. The slope of the GCC (increased in spring and decreased in autumn) was moderate in the evergreen coniferous forest compared with that in the deciduous forest. In the pine forest, the beginning of growth occurred earlier than that in the red oak forest, whereas the end of growth was later. Verification of the accuracy of the phenophases showed high accuracy with root-mean-square error (RMSE) values of 0.008 (region of interest [ROI]1) and 0.006 (ROI3). These results reflect the tendency of the GCC trajectory in a northern temperate type deciduous broadleaf forest. Based on the results, we propose that repeat imaging using digital cameras will be useful for the observation of phenophases.

• Korean Journal of Ichthyology
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• v.21 no.2
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• pp.87-92
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• 2009

Histological investigation of seasonal changes of the mucus cells of ricefield-dwelling mud loach Misgurnus mizolepis was carried out on the skin in three regions of the fish: dorsal, lateral, and occipital. Although there were no significant differences in general morphology, the mucus cells of the epidermis showed a severe change in size and number by skin region. The density of the mucus cells was generally the highest in winter and the lowest in summer in all three skin regions. In particular, during two distinct periods, March to April when water is supplied to the ricefields, and August to September when the ricefields become dry after harvest, showed that the change in density and distribution of the mucus cells in both lateral and occipital regions is greater than during any other period. Moreover, the mucus cells for the dorsal and occipital regions temporally increased in size in June during the period of the highest water temperature of the year. Therefore, we may consider these seasonal changes as part of a protective adaptation to overcome extreme environmental conditions and to increase uptake of oxygen by cutaneous respiration.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.5
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• pp.461-468
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• 2010

This study investigated variation of rainwater quality by seasonal and storage duration of rainwater in Changwon city. Seasonally, the pollutants concentration of rainwater were higher in spring and winter. In the case of rainwater and storage rainwater quality, pH of rainwater was 4.3, storage rainwaters were 6.0 and Turbidity increased about 8 times from 1.82 NTU to 14.61 NTU. The changes of storage water quality during the storage period, initial KMnO4 consumption rainwater was exceeded drinking water standard. Total solid in rainwater was detected as 116 mg/L, it tended to stable at around 70∼80mg/L after storage period for a 6day.

• Journal of Wetlands Research
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• v.24 no.4
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• pp.288-300
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• 2022

As industrialization and urbanization progress extensively, climate change is intensifying due to greenhouse gas emissions. In Korea, the average temperature increased, and the annual precipitation also increased due to climate change. In addition, the meaning of the solar term, which expresses seasons according to the movement of the sun, is also being overshadowed. Therefore, this study investigated the seasonal changes and solar-term changes of average temperature and precipitation observed in the past as well as simulated for future RCP climate change scenarios for five major regions (Capital Region, Gyeongsang, Chungcheong, Jeolla, and Gangwon). For the seasonal length, the length of summer became longer, the length of winter became shorter nationwide, and the precipitation in summer generally increased compared to the past. In the Chungcheong area, under the RCP 8.5 scenario, the length of summer increased by 46%, precipitation increased by 16.2%, and the length of winter decreased by 31.8% compared to the past. For the solar term, the temperature rose in all seasons. In the Chungcheong area, under the RCP 8.5 scenario, the temperature of major heat increased by 15.5%, and the temperature of major cold increased by 75.7% compared to the past. The overall results showed that the hydrological characteristics of the season and solar term were identified by region, which can be used as basic data to prepare policies to respond to climate change.