• 한국지구과학회:학술대회논문집
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• 한국지구과학회 2010년도 춘계학술발표회 논문집
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• pp.134-134
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• 2010

Sea ices at the Tatarskiy Straitin the East/Japan Sea appear from November to April. Cold and fresh water, melted from the sea ices, may contain nutrients which are indispensable to spring bloom of phytoplankton and may provide a preferable condition to the spring bloom through changes in vertical structure of water column and stratification. Relation between the spring bloom along the Primorye coast and sea ices in the Tatarskiy Strait were investigated using multi-satellite multi-sensor data; ten-year SeaWiFS chlorophyll-a concentration data and PAR data, sea surface temperatures from NOAA/AVHRR, sea ice concentration and near-surface wind speed data from DMSP/SSMI, near-surface wind vectors from QuikSCAT, and others. We provided evidences of southwestward flowing cold water masses from sea ice and its relation of chlorophyll-a concentration. This study showed that year-to-year variations of chlorophyll-a concentration in spring were positively correlated with those of sea ice concentrations at the Tatarskiy Strait.

• Journal of Information Technology Applications and Management
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• 제19권1호
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• pp.85-100
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• 2012

The development of technology causes a lot of change. Many researchers have insisted that the proliferation of cyber space changes the physical space. Their insistences have been accumulated into three aspects. Firstly, the proliferation of cyber space brings out the concentration in the physical space, secondly the decentralization and lastly both at the same time. In Korea, the concentration of plastic surgery clinics has taken place in Kangnam-gu area at similar period of the Internet proliferation. In this research, we execute empirical study of whether the concentration of plastic surgery in specific areas correlates with the proliferation of cyber space or not. In order to do this, we verified homogeneity of plastic surgery websites between Kangnam-gu and Non-Kangnam-gu areas. Also, we used three statistical and data-mining techniques which are Multi-discriminant analysis, Decision tree analysis and artificial neural network analysis. As a result, there was homogeneity between two different area plastic surgery clinics websites, but there was not big heterogeneity as well. Therefore, in this case of concentration of plastic surgery in Korea, the proliferation of cyber space restrictively correlates with the concentration of physical space.

• 한국측량학회지
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• 제37권6호
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• pp.517-523
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• 2019

PM₁₀ 농도는 시간 및 공간 의존성을 동시에 가지는 시공간 데이터이지만 현실적으로 연속적인 시공간 데이터를 획득하는 것은 쉬운 일이 아니다. 본 연구에서는 위성영상과 대기질 및 기상 관측 센서 데이터를 복합적인 딥러닝 모델에 적용하여 시공간 해상도를 향상시키는 모델을 설계하였다. 설계된 딥러닝 모델은 기상, 토지 이용 등 PM₁₀ 농도에 영향을 줄 수 있는 인자를 이용하여 학습하였으며, 대기질 및 기상 관측 데이터만을 이용하여 15분 단위의 30m×30m의 공간해상도를 PM₁₀ 영상을 생성하였다.

• 한국환경과학회지
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• 제14권11호
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• pp.1035-1047
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• 2005

By using hourly $NO_2$ concentration data$(1998\~2000)$ at the Busan Metropolitan City air qualify monitoring sites, characteristics of daily mean value of $NO_2$ concentration was discussed in space and time. The correlation between $NO_2$ concentration and other relating air pollutants was analyzed by using SAS program and meteorological parameters as well. After choosing representative 4 areas, this study used hourly concentration data$(1998\~2000)$ from air quality monitoring sites on $NO_2,\;NO,\;O_3,\;CO,\;SO_2\;and\;PM_{10}$. Typical metropolitan characteristics of two peaks in a day was shown in the variation of $NO_2$ concentration of Busan city.

• 한국멀티미디어학회논문지
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• 제20권8호
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• pp.1208-1215
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• 2017

Recently, people's attention and worries about fine particulate matter have been increasing. Due to the construction and maintenance costs, there are insufficient air quality monitoring stations. As a result, people have limited information about the concentration of fine particulate matter, depending on the location. Studies have been undertaken to estimate the fine particle concentrations in areas without a measurement station. Yet there are limitations in that the estimate cannot take account of other factors that affect the concentration of fine particle. In order to solve these problems, we propose a framework for estimating the concentration of fine particulate matter of a specific area using meteorological data and traffic data. Since there are more grids without a monitor station than grids with a monitor station, we used a domain adversarial neural network based on the domain adaptation method. The features extracted from meteorological data and traffic data are learned in the network, and the air quality index of the corresponding area is then predicted by the generated model. Experimental results demonstrate that the proposed method performs better as the number of source data increases than the method using conditional random fields.

• 한국대기환경학회지
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• 제9권4호
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• pp.303-309
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• 1993

An observational study of urban heat island was carried out using field data obatined during 6 days in May and August 1992 in Chunchon(population size 180.000). Air temperature was measured at 64 points along two sampling ruoutes by themisters attached to cars. Both routes cover urban and rural area and across the cneter of urban area. Continuous observation of air sonde was perfomed to clarify heights of nocturnal boundary layer(NBL) at the center of urban area. Surface meteorological observations were performed at both urban and rural sites. This study showed that heat island phenomena was obviously observed at the urbanized area during the night time with low wind speed. The average NBL heights exteded to about 10 meters, but varied with meteorological conditions. After sunset, the air temperature decreased with time at both sites and cooling rate at the urban site was greater than the rural site. The maximum heat island intensity was 7.5$^{\circ}$C at 21 LST, May 4. Usingthe two meteorological data sets obtained from urban and rural sites, the air pollutant concentration was calculated by Gaussian plume model which can obtain not only horizontal distribution of concentration but also vertical distribution. The result indicated that the concentration resulted from urban meteorological data set was lower than that from rural meteorological data set. It was also calculated that the air pollutant extended to higher level in urban meteorological data set than that in rural meteorological data set.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권2호
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• pp.907-923
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• 2020

For the severe haze situation in the Beijing-Tianjin-Hebei region, conventional fine particulate matter (PM2.5) concentration prediction methods based on pollutant data face problems such as incomplete data, which may lead to poor prediction performance. Therefore, this paper proposes a method of predicting the PM2.5 concentration based on image analysis technology that combines image data, which can reflect the original weather conditions, with currently popular machine learning methods. First, based on local parameter estimation, autoregressive (AR) model analysis and local estimation of the increase in image blur, we extract features from the weather images using an approach inspired by free energy and a no-reference robust metric model. Next, we compare the coefficient energy and contrast difference of each pixel in the AR model and then use the percentages to calculate the image sharpness to derive the overall mass fraction. Furthermore, the results are compared. The relationship between residual value and PM2.5 concentration is fitted by generalized Gauss distribution (GGD) model. Finally, nonlinear mapping is performed via the wavelet neural network (WNN) method to obtain the PM2.5 concentration. Experimental results obtained on real data show that the proposed method offers an improved prediction accuracy and lower root mean square error (RMSE).

• 한국대기환경학회지
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• 제34권5호
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• pp.668-676
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• 2018

This study has developed a technique to divide the aerosol optical depth of the entire aerosol (${\tau}_{total}$) into the dust optical depth (${\tau}_D$) and the pollution particle optical depth (${\tau}_P$) using the AERONET sun/sky radiometer data provided in Version 3. This method was applied to the analysis of AERONET data observed from 2006 to 2016 in Beijing, China, Seoul and Gosan, Korea and Osaka, Japan and the aerosol optical depth trends of different types of atmospheric aerosols in Northeast Asia were analyzed. The annual variation of ${\tau}_{total}$ showed a tendency to decrease except for Seoul where observation data were limited. However, ${\tau}_D$ tended to decrease when ${\tau}_{total}$ were separated as ${\tau}_D$ and ${\tau}_P$, but ${\tau}_P$ tended to increase except for Osaka. This is because the concentration of airborne aerosols, represented by Asian dust in Northeast Asia, is decreased in both mass concentration and optical concentration. However, even though the mass concentration of pollution particles generated by human activity tends to decrease, Which means that the optical concentration represented as aerosol optical depth is increasing in Northeast Asia.

• 국제물리치료학회지
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• 제2권1호
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• pp.260-266
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• 2011

The purpose of this study was to investigate the effects of meditation music with lumbar stabilization exercise on balance, concentration and muscle activation. Participants are divided into Group A and Group B. Group A listened to meditation music while doing 4 sets of lumbar stabilization exercise. Group B did not listen to meditation music while doing 4 sets of lumbar stabilization exercise. Surface EMG data was obtained rectus abdominis, external oblique, erector spinae, multifidus muscle during lumbar stabilization exercise. To examine the effect of before-after experiment for concentration and balance, paired t-test was adopted. Changes in EMG data of each muscles were analyzed by independence t-test. There were statistically significant increasing at concentration level and balance level in Group A. But significant difference was not shown in muscle activation. The clinical effect of the meditation music with lumbar stabilization exercise was investigated in this study with more excellent results in concentration and balance. In conclusion, these results suggest that meditation music and lumbar stabilization exercise may be useful in elderly people.

• 한국화재소방학회논문지
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• 제8권1호
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• pp.3-8
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• 1994

A new test system was established to measure the flame extinguishing concentration of Halon alternatives. The main characteristic of this system is to use the solid paraffin with a wick instead of liquid fuel, such as n-Heptane. Our results showed that the extinguishing concentration of compounds was lower than that of other existing data, but the trend was consistent with others. The flame extinguishing concentration of all tested compounds were not almost effected by gas flow velocity. The system produces good reliable data with a minimum error for measuring the flame extinguishing concentration. Therefore our new system can be utilized as a standard equipment to evaluate Halon alternatives.