• Journal of Korean Society on Water Environment
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• v.30 no.5
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• pp.503-511
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• 2014

The temporal and spatial analyses of total nitrogen (TN) fractionation were conducted in order to understand 1) total nitrogen components in streams and 2) their patterns in rainy and dry seasons. The result showed that the concentration of nitrogen components in stream water was lower in non-urban area and getting higher in urban area. Dissolved total nitrogen (DTN) was 95~97.7% of total nitrogen in streams, and the proportion of dissolved organic nitrogen (DON) and ammonia nitrogen ($NH_3-N$) was higher with increasing urban area. The concentration of total nitrogen and nitrate nitrogen ($NO_3-N$) were highest in winter among four seasons. The result was showed that concentration of $NH_3-N$ was same variation as concentrations of TN and $NO_3-N$ in urban-rural complex and urban areas, except rural areas. During rainy season, concentrations of particulate organic nitrogen (PON) and $NH_3-N$ increased in rural areas and decreased in both urban-rural complex and urban areas. Correlation between total nitrogen components and land uses was positively correlated with site > paddy, and negatively correlated with forest. The variation of total nitrogen concentration was determined by $NO_3-N$ in non-urban areas, by $NO_3-N$ and $NH_3-N$ in urban-rural complex and by $NH_3-N$ in the urban areas.

• Journal of Environmental Science International
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• v.24 no.6
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• pp.807-817
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• 2015

In this study the urban atmospheric environment map in Busan was made and it consist of the atmospheric environment element map and the atmospheric environment analysis map. The atmospheric environment element map covered the topography, the urban climate, the air pollutant emission, ozone and PM10 concentrations in Busan and the atmospheric environment analysis map included the thermal environment and the wind flow by using WRF meteorological numerical simulation. The meteorological elements from 2007 to 2011 in Busan were used in this study. As a result, in the center of Busan and Buk-gu along to the Nakdong river was the temperature high. To analyze the air flow of Busan 3 clusters depending on the wind direction were extracted with the cluster analysis. The results of the analysis on the detailed wind field of each cluster showed that the weak ventilation could be happened locally at the specific meteorological condition.

• Journal of People, Plants, and Environment
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• v.21 no.6
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• pp.461-471
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• 2018

The role of urban agriculture should not be limited as a small-scale crop cultivation activity as it was, but it has to be considered as an entire process of a agriculture activity for the restoration of the city community. This study is based on the assumption that there has been a significant change in urban lifestyle and urban farming preference, considering the overall improvement in standard of living after implementation of five day work week system. It was conducted for urban citizens who were interested in actual urban agriculture for ages 19 and over who visited the Korea Urban Agriculture Exhibition in 2018. Only 115 valid samples were used for the empirical analysis. To analyze the demographic characteristics and effects of urban agriculture, frequency analysis and descriptive statistics were conducted. In order to analyze the reliability and validity of the measurement variables of the effect, the variables that deteriorate the validity were removed and 15 variables of the urban agricultural effect were selected. According to the result of factor analysis, three factors were extracted as follows: socially sustainable effect, negative effect and economically sustainable effect. In order to examine the effects of urban agriculture depending on income level, the one-way ANOVA, which is a statistical technique for verifying differences in the sample means, was performed. The psychological stability of people, the recovery of humanity through communion with nature, and the vitalization of agriculture linked with local agriculture had significant correlations with income level. The negative effect showed no significant correlation with income level. The improvement of the local environment was found to have an impact in relation with income level. We expect that there will be more studies on policies for the new types and models of urban agriculture in order to make it easier for urban citizens to approach it.

• Journal of Korean Society for Atmospheric Environment
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• v.34 no.5
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• pp.697-707
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• 2018

A fast running model comprising the climate change effects is proposed for urban heat environment simulations so as to be used in urban heat island studies and/or the urban planning practices. By combining Hot City Model, a high resolution urban temperature prediction model utilizing the Lagrangian particle tracing technique, and the numerical weather simulation data which are constructed up to year of 2100 under the climate change scenarios, an efficient model is constructed for simulating the future urban heat environments. It is applicable to whole city as well as to a small block area of an urban region, with the computation time being relatively short, requiring the practically manageable amount of the computational resources. The heat environments of the entire metropolitan Seoul area in South Korea are investigated with the aid of the model for the present time and for the future. The results showed that the urban temperature gradually increase up to a significant level in the future. The possible effects of green roofs on the buildings are also studied, and we observe that green roofs don't lower the urban temperature efficiently while making the temperature fields become more homogeneous.

• Journal of The Korean Association For Science Education
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• v.31 no.7
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• pp.1040-1054
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• 2011

This formative evaluation study presents a professional development program, "Earth Science Systems for Teachers (ESST)" held in a Midwest State in the United States. This study investigates how a professional development for urban teachers affects the teacher participants' perceptions of using the urban environment for their science teaching and their lesson unit development. The purpose of the program was to help urban teachers create science units using the urban geologic environment and its connection to urban students' everyday lives. The participant teachers' daily journal entries during the program, their lesson plans before and after the program, as well as their teaching reflections were collected as major data source. The teachers' daily journal entries were analyzed qualitatively and their pre-post lessons were analyzed quantitatively using a lesson plan analysis tool, Culturally Relevant Science Teaching Perspectives (CRSTP) was developed by the author. The lesson analysis tool was used to assess teachers' science lesson plans in the perspective of culturally relevant pedagogy and place-based pedagogy. The major findings include: 1) The teacher participants' field experiences in urban geologic sites and urban environments help the teachers to change their perceptions of using the urban environment as a teaching resource and 2) there were significant differences in their pre and post lesson unit scores based on CRSTP (P<. 01). The implications of this study are also discussed.

• KIEAE Journal
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• v.11 no.3
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• pp.3-9
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• 2011

For urban development, natural covering area such as urban green or river is more rapidly reducing than artificial surface covering area like concrete or asphalt, so thermal environment in a city is being drastically deteriorated. Recently, since people recognize the importance of parks or rivers in a city which play roles as an environmental buffer in it, many studies and policies consider how to improve the life quality of citizens and urban environment. This study aims to examine the status of thermal environment variation in the parks and rivers of the city which is the subject of this research and provide foundational data for urban environment plans through research on temperature variation rate and temperature controlling effect.

• Journal of Environmental Science International
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• v.23 no.12
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• pp.2101-2106
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• 2014

The urban wetland park is an indispensable part of an ecological city. It has aroused widespread attention and even quickly planning and construction around the country. But, in terms of the nature of the urban wetland park, there is a contradiction between the protection of urban wetland resources and the openness of the urban park for public. This article starts with the necessity for construction of urban wetland park, more over expound the existent problems between the protection and openness of the urban wetland park and to propose appropriate measures through the case study on Nanhu National Urban Wetland Park, Tangshan.

• Asian Journal of Atmospheric Environment
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• v.5 no.1
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• pp.29-40
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• 2011

In this study, the effects of an urban thermal environment on air quality were investigated using hourly surface weather observation data and air quality data over six summers from 2000 to 2005 in two cities on the Korean Peninsula. One, the city of Daegu, is representative of basin topography and the other, the city of Busan, represents a coastal area. It is known that the characteristics of an urban thermal environment are represented as an "urban heat island". Here, we focus on the nighttime urban thermal environment, which is called a "tropical night", during the summer. On tropical nights in Busan, the temperature and cloud cover levels were higher than on non-tropical nights. Wind speed did not appear to make a difference even on a tropical night. However, the frequency of southwestern winds from the sea was higher during tropical nights. The prevailing southwest winds in all areas meant an inflow of air from the sea. So at most of the air quality stations, the ozone concentration during tropical nights was lower than during non-tropical nights. In Daegu, the tropical nights had higher temperatures and cloud covers. Despite these higher temperatures, the ozone concentration during the tropical nights was lower than that on non-tropical nights at most of the air quality stations. This feature was caused by low irradiance, which in turn caused an increased cloud cover. Wind speed was stronger during the tropical nights and dispersed the air pollutants. These meteorological characteristics of the tropical nights reduced ozone concentrations in the Daegu Basin.

• Journal of the Korean Institute of Landscape Architecture
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• v.23 no.2
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• pp.167-181
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• 1995

An Ecocomplex is proposed for ecological design of the estuarine environment of Han River, which is designed upon an alternative mamagement concept of estuarine environment. The concept reveals interrelationships among estuary, delta region and urban inland with inputs/outputs and feedbacks among them. The Ecocomplex emphasizes an integration of wastewater treatment with aquaculture, agriculture and recreation, and carries out ecological treatment, recycling, and harvest processes. A module of wastewater treatment pond system is employed in the Ecocomplex, which treats a flow of 3,786 ㎥/day and is composed of a four-facultative-pond series. Treatment ponds stabilize wastewater discharged from the urban area, and concurrently produce algae for commercial or recreational fish farming. Effluent from treatment and fish ponds is reused for agricultural production. Through the waste-algae-fish-vegetable-recreation processes, wastewater from the urban settlement is recycled back to the urban ecosystem. This resource-conserving design approach can maintain a sustainable urban ecosystem, managing an estuarine environment more naturally, healthly, and economically.

• Journal of Positioning, Navigation, and Timing
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• v.12 no.4
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• pp.379-389
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• 2023

According to the Korea Urban Air Mobility (K-UAM) Concept of Operation (ConOps), the Global Navigation Satellite System (GNSS) is recommended as the primary navigation system and the performance specification will be implemented considering the standard of Performance Based Navigation (PBN). However, by taking into account the characteristics of an urban environment and the concurrent operations of multiple UAM aircraft, the current PBN standards for civil aviation seem difficult to be directly applied to an UAM aircraft. Therefore, by referring to technical documents published in the literature, this paper examines the feasibility of applying the proposed performance requirements to K-UAM, which follows the recommendation of navigation performance requirements for K-UAM. In accordance with the UAM ConOps, the UAM aircraft is anticipated to maintain low altitude during approach and landing phases. Subsequently, the navigation performance degradation could occur in the urban environment, and the primary degradation factor is identified as multipath error. For this reason, to ensure the safety and reliability of the K-UAM aircraft, it is necessary to analyze the degree of performance degradation related to the urban environment and then propose an alternative aid to enhance the navigation performance. To this end, the aim of this paper is to model the multipath effects of the GNSS in an urban environment and to carry out the simulation studies using the real GNSS datasets. Finally, the initial navigation performance requirement is proposed based on the results of the numerical simulation for the K-UAM.