• Atmosphere
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• v.27 no.2
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• pp.119-131
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• 2017

We present and discuss the Tropopause Folding Turbulence Detection (TFTD) algorithm for the Korean Communication, Ocean, Meteorological Satellite (COMS) which is originally developed for the Tropopause Folding Turbulence Product (TFTP) from the Geostationary Operational Environmental Satellite (GOES)-R. The TFTD algorithm assumes that the tropopause folding is linked to the Clear Air Turbulence (CAT), and thereby the tropopause folding areas are detected from the rapid spatial gradients of the upper tropospheric specific humidity. The Layer Averaged Specific Humidity (LASH) is used to represent the upper tropospheric specific humidity calculated using COMS $6.7{\mu}m$ water vapor channel and ERA-interim reanalysis temperature at 300, 400, and 500 hPa. The comparison of LASH with the numerical model specific humidity shows a strong negative correlation of 80% or more. We apply the single threshold, which is determined from sensitivity analysis, for cloud-clearing to overcome strong gradient of LASH at the edge of clouds. The tropopause break lines are detected from the location of strong LASH-gradient using the Canny edge detection based on the image processing technique. The tropopause folding area is defined by expanding the break lines by 2-degree positive gradient direction. The validations of COMS TFTD is performed with Pilot Reports (PIREPs) filtered out Convective Induced Turbulence (CIT) from Dec 2013 to Nov 2014 over the South Korea. The score test shows 0.49 PODy (Probability of Detection 'Yes') and 0.64 PODn (Probability of Detection 'No'). Low POD results from various kinds of CAT reported from PIREPs and the characteristics of high sensitivity in edge detection algorithm.

• Environmental Engineering Research
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• v.11 no.3
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• pp.134-142
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• 2006

The treatment of high-strength swine wastewater by anaerobic digestion combined with an aquatic plant system was investigated. Anaerobic digestion of swine wastewater gave volatile solids (VS) removal efficiencies of 43.3%, 52.1% and 54.5% for hydraulic retention times (HRTs) of 20, 30, 40 days, respectively. The removal efficiencies of VS, total chemical oxygen demand (TCOD) and soluble chemical oxygen demand (SCOD) decreased with increasing VS volumetric loading rate (VLR). Higher organic removal efficiency was observed at longer HRTs for the same VS volumetric loading rate. As VS volumetric loading rate increased, biogas production increased and the methane content of the biogas decreased. Experiments using duckweed (Lemna species) as an aquatic macrophyte gave the following results. In the case of nitrogen, removal efficiency was above 60% and effluent concentration was below 10.0 mg/L when the influent ammonia-N loading was about $1.0\;g/m^2/day$. In the case of phosphorus, removal efficiency was above 55% and effluent concentration was below 2.0 mg/L when the influent $PO_4$-P loading was about $0.15\;g/m^2/day$. In addition, crude protein and phosphorus content of duckweed biomass increased from 15.6% to 41.6% and from 0.8% to 1.6%, respectively, as the influent nutrient concentration increased. The treatment of high-strength swine wastewater by anaerobic digestion combined with an aquatic plant system offers good performance in terms of organics and nutrient removal for relatively low operation and maintenance costs. The results indicate that under appropriate operational conditions, the effluent quality is within the limits set by Korean discharge criteria.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.15 no.1
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• pp.73-87
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• 2012

This study was conducted to provide sustainable measures for conservation and management to protect valuable natural/ecological resources, offer differentiated quality assurance services for eco-tourism products, and explore measures for eco-tourism certification/designation systems. To achieve its goals, the study discussed domestic and overseas trends and literatures that concern eco-tourism certification/designation system and investigated case studies that were presently operational. A group of experts and a group of non-experts were surveyed separatedly to investigate the awareness of the national eco-tourism certification/designation system. The results from the investigation indicate that Europe, since the late 1990s to early 2000, has actively introduced a system that establishes and operates a dedicated institution, and European members have created a cooperation framework to formulate international partnerships and develop standardized assessment benchmarks to adhere to the goals of the system, the period for certification was designated from one year to five years, and renewals were granted based on periodic monitoring and reassessment. In Korea, from early 2000, the Ministry of Culture, Sorts and Tourism and other organizations have certified product quality and assessed travel products and national park tour programs. The certification period was established to be set between one and three years, and the vast majority were not reassessed. Upon investigating the results for awareness of national eco-tourism certification/designation system, a high number of respondents agreed with the need to establish a eco-tourism certification/designation system (90% of respondents), and the respondents cited eco-tourism quality assurance, conservation of value, means to maintain established institutions, and environmental education and information as reasons for needing a certification/designation system. In Korea, a certification/designation system for the eco-tourism industry is presently in operation, but the system regulates target institutions based on their characteristics. Therefore, this study proposes its suggestions via various categories, including designated institutions, designated purpose, designated subjects, designated organization, laws, regulations, and incentives.

• Journal of Aerospace System Engineering
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• v.18 no.4
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• pp.96-101
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• 2024

The Synthetic Aperture Radar (SAR) is equipped with a Transmitter/Receiver (TR) module, which serves as the signal transmission and reception unit for acquiring image data. The TR module generates significant heat during signal generation and amplification, potentially degrading performance or causing mission failure. Furthermore, launch and operational environments may result in structural damage to the components. Thus, assessing the thermal and structural safety of the TR module through thermal and vibration tests is essential to guarantee its safety. Safety assessments can be verified through environmental tests prescribed in MIL-STD-883. This paper explores the thermal and structural safety characteristics of the TR module by simulating test environments using finite element analysis prior to conducting environmental tests.

• Journal of Korean Society of Water and Wastewater
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• v.38 no.3
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• pp.141-153
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• 2024

The purpose of this study is to analyze the correlation between ecotoxicity and water quality items using Daphnia magna in public sewage treatment plant process and to obtain operational data to control ecotoxicity through research on removal efficiency. The average value of ecotoxicity was 1.39 TU in the influent, 1.50 TU in the grit chamber, and 0.84 TU in the primary settling tank and it was found that most organic matters, nitrogen, and phosphorus were removed through biological treatment in the bioreactor. Using Pearson's correlation analysis, the positive correlation was confirmed in the order of ecotoxicity and water quality items TOC, BOD, T-N, NH3-N, SS, EC, and Cu. As a result of conducting a multilinear regression analysis with items representing positive correlation as independent variables, the regression model was found to be statistically significant, and the explanatory power of the regression model was about 81.6%. TOC was found to have a significant effect on ecotoxicity with B=0.009 (p<.001) and Cu with B=16.670 (p<.001), and since the B sign is positive (+), an increase of 1 in TOC increases the value of ecotoxicity by 0.009 and an increase in Cu by 1 increases the value of ecotoxicity by 16.670. TOC (β=0.789, p<.001) and Cu (β=0.209, p<.001) were found to have a significant positive effect on ecotoxicity. TOC and Cu have a great effect on ecotoxicity in the sewage treatment plant process, and it is judged that TOC and Cu should be considered preferentially and controlled in order to efficiently control ecotoxicity.

• Journal of Environmental Impact Assessment
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• v.27 no.3
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• pp.322-333
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• 2018

This study was carried out to measure atmospheric environmental improvement effect and estimate its social benefit of thermal power plants through Environmental Impact Assessment (EIA) for quantitative analysis about operational performances of EIA. In this study, 'EIA outcome' is defined as whether or not the system is implemented, therefore, environmental standard to be followed by each project and consultation contents were compared. In total 60 cases of thermal power plant construction projects that have been consulted over the past 10 years since 2010, major air pollutants have been significantly reduced after the implementation of EIA. The $PM_{10}$ reduced annual 3,745 tons, $NO_2$ by 74,569 tons, and $SO_2$ by 37,647 tons, which were estimated at approximately 240 billion won~5 trillion 967 billion won per year for social benefit. This means the total cost of power plant operations will be cut to 7 trillion 192 billion won~178 trillion 994 billion won over a 30-year period. The reduced amount of air pollutants emitted by energy generation facilities across the country is worth 50%, and its economic value is larger than the annual Current Health Expenditure in Korea. This is meant by the fact that all projects are subject to uniform criteria under the existing relevant regulation, but that each project plans are optimized according to the characteristics of target areas and projects through the process of EIA.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.3
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• pp.189-194
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• 2012

In this study, a 3-stage biological aerated filter (BAF) system was proposed to enhance nitrogen removal in the treatment of low carbon to nitrogen ratio (C/N ratio) municipal wastewater. Laboratory experiments were conducted to evaluate the effects of dynamic-flow at the HRT of 6 h. Results of the long-term operation of 3-stage BAF systems showed that the dynamic-flow enabled the total nitrogen removal (T-N) removal efficiency of the system to be about 7 % higher than that of non-dynamic-flow system in treating domestic wastewater due to the more efficient use of organic substrates. The overall $NH_4$-N removal performance was stable during the operational period due to the unique system configuration where independent nitrification occurred. It was concluded that the 3-stage BAF system proposed in this study provided excellent performance in the removal of nitrogen by employing dynamic-flow and three columns functioning as sorption, denitrification and nitrification, respectively.

• Korean Institute of Interior Design Journal
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• v.19 no.2
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• pp.117-125
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• 2010

Theories and concepts emerging in new media environment are influencing the field of current spatial design. Art and technology have always coexisted, not but they are differentiated in two parts. They show new communicational paradigm in terms of supplementary position each other. The fact that examining the expression method and the communicational structure of today's new media art will be an analytical tool which analyzes the concepts of contemporary spatial design. For this, we attempt to use the Bolter and Gusin's remediation theory as analytical tool. First of all, we consider its theoretical aspects, and then, classify them according to the creation method, and investigate the characteristics of expression according to their types. We prepared an framework of analysis using the Remediation theory and its traits. We reviewed the relations between new media and spaces concerning remediation. After researching, we could analyze the cognitive aspects between new media and spaces as immediacy, and recognize the operational aspects of visual image as hypermediacy. Through the analysis, we could recognize the traits that digital environmental simulacres, sense of telepresence, and non-linear hypermediacy etc. remediate with repeating of mediation of mediation.

• Journal of the Korean earth science society
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• v.39 no.4
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• pp.305-316
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• 2018

Satellite-derived sea surface winds (SSWs) and atmospheric motion vectors (AMVs) over the global ocean, particularly including the areas in and around tropical cyclones (TCs), have been provided in a real-time and continuous manner. More and better information is now derived from technologically improved multiple satellite missions and wind retrieving techniques. The status and prospects of key SSW products retrieved from scatterometers, passive microwave radiometers, synthetic aperture radar, and altimeters as well as AMVs derived by tracking features from multiple geostationary satellites are reviewed here. The quality and error characteristics, limitations, and challenges of satellite wind observations described in the literature, which need to be carefully considered to apply the observations for both operational and scientific uses, i.e., assimilation in numerical weather forecasting, are also described. Additionally, on-going efforts toward merging them, particularly for monitoring three-dimensional TC wind fields in a real-time and continuous manner and for providing global profiles of high-quality wind observations with the new mission are introduced. Future research is recommended to develop plans for providing more and better SSW and AMV products in a real-time and continuous manner from existing and new missions.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.6D
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• pp.765-769
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• 2011

The existing portable reference equipment for ITS systems performance evaluation has several limitations. First, it is difficult to set up and operate the equipment in the road section with the shoulder width equal to or smaller than 1.5m. Secondly, the crash with a car could lead to severe accident since it is big and heavy. Lastly, it cannot collect data from multiple lanes at a time. In this research the characteristics of the USN-based portable reference equipment developed to overcome shortcomings of the existing portable reference equipment were analyzed qualitatively and its performance level was evaluated through the field test. Consequently, the USN-based portable reference equipment turned out to overcome the operational shortcomings and satisfy the performance level required for the portable reference equipment.