• 한국지하수토양환경학회지:지하수토양환경
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• 제14권5호
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• pp.41-50
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• 2009

제주도 지하수관측망의 지하수위 측정 자료에 대하여 모수 및 비모수 경향분석을 수행하였다. 분석대상은 2001년부터 1년 이상 관측된 관측정으로 총 106개 관측정 중 94개가 이에 해당된다. 모수분석은 일평균 및 월중앙값을 이용한 선형회귀분석을 실시하였으며 비모수분석은 월중앙값에 대해 Mann-Kendall trend test와 Sen's trend test를 적용하였다. 선형회귀분석 결과 일평균값에 대하여 58.5%가 감소경향을 나타났으며 월중앙간에 대해서는 79.8%가 감소하는 경향을 보였다. Mann-Kendall trend test와 Sen's trend test를 신뢰수준 95%와 99%로 실시한 결과 두 분석 모두 일치하는 결과를 보였다. 95% 신뢰수준에서는 32%가 감소경향을 보였으며 3%가 증가경향을 나타냈고, 나머지 65%는 경향성이 나타나지 않았다. 또 99%신뢰수준에서는 16%가 감소경향을 보였으며 2%가 증가경향을 나타냈고 그리고 나머지 82%에서는 경향성이 없는 것으로 나타났다. 수위하강이 우세하게 나타난 지역은 제주도 북서부 및 남서부의 해안지역으로 도시 및 관광지에서의 다량의 지하수 양수와 관련 있는 것으로 사료된다.

• 농약과학회지
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• 제19권1호
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• pp.32-40
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• 2015

본 연구는 유통 농산물의 잔류 실태를 조사하여 잔류농약에 대한 안전성을 평가하기 위해 수행되었다. 전국 9개 지역에서 수거된 농산물 15개 품목 232건을 식품공전 다종농약다성분 분석법으로 분석하였으며, GC/MSMS로 분석 가능한 농약 196종을 대상으로 하였다. 그 결과 53건의 시료에서 64종의 농약이 검출되었고 이 중 chlorpyrifos와 procymidone이 가장 빈번히 검출되었다. 검출된 64종 중 깻잎에서 검출된 chlorpyrifos와 복숭아에서 검출된 picoxystrobin은 잔류허용기준을 초과하였으며, 나머지는 각각의 잔류허용기준을 초과하지 않았다. 잔류허용기준을 초과한 chlorpyrifos와 picoxystrobin을 포함한 검출 농약에 대해 위해평가를 수행한 결과, 1일 섭취허용량(acceptable daily intake, ADI) 대비 1일 추정섭취량(estimated daily intake, EDI)이 0.001~0.902%로 조사되어 매우 낮은 수준임을 확인할 수 있었다. 이번 연구 결과 유통 농산물에서 잔류농약은 안전하게 관리되고 있음을 확인 할 수 있었고, 향후 식품안전 정책 수립의 기초 자료로 활용할 수 있을 것을 생각된다.

• 한국환경보건학회지
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• 제33권5호
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• pp.365-371
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• 2007

To evaluate the effect of air pollution on respiratory health in children, We conducted a longitudinal study in which children were asked to record their daily levels of Peak Expiratory Flow Rate(PEFR) using potable peak flow meter(mini-Wright) for 4 weeks. The relationship between daily PEFR and ambient air particle levels was analyzed using a mixed linear regression models including gender, age in year, weight, the presence of respiratory symptoms, and relative humidity as an extraneous variable. The daily mean concentrations of $PM_{10}$ and $PM_{2.5}$ over the study period were $64.9{\mu}g/m^3$ and $46.1{\mu}g/m^3$, respectively. The range of daily measured PEFR in this study was $182{\sim}481\;l/min$. Daily mean PEFR was regressed with the 24-hour average $PM_{10}(or\;PM_{2.5})$ levels, weather information such as air temperature and relative humidity, and individual characteristics including sex, weight, and respiratory symptoms. The analysis showed that the increase of air particle concentrations was negatively associated with the variability in PEFR. We estimated that the IQR increment of $PM_{10}$ or $PM_{2.5}$ were associated with 1.5 l/min (95% Confidence intervals -3.1, 0.1) and 0.8 l/min(95% CI -1.8, 0.1) decline in PEFR. Even though this study showed negative findings on the relationship between respiratory function and air particles, it was worth noting that the findings must be interpreted cautiously because exposure measurement based on monitoring of ambient air likely resulted in misclassification of true exposure levels and this was the first Korean study that $PM_{2.5}$ measurement was applied as an index of air quality.

• 한국지구과학회지
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• 제23권5호
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• pp.424-435
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• 2002

이 연구에서는 1997년부터 1999년 3년 간 대구광역시의 시간별 O$_3$ 농도 자료와 기상자료를 분석하여, 대구시의 고농도 오존 발생 일에 나타나는 기상학적 특성을 알아보고자 한다. 고농도 오존 발생 일의 선정은 우리나라 환경기준치인 1시간 평균 오존 농도 100ppb를 초과한 지점이 대구시의 6개 측정 지점 중 한 지점이라도 있는 경우로 정했다. 고농도 오존 발생 일은 13일이었으며, 5월과 9월이 가장 그 빈도가 높았다. 고농도 오존 발생 일의 하루 평균 최대 오존 농도는 81.6ppb이었으며, 8시간 평균 농도는 58.6ppb이었다. 이는 대구의 오존 오염이 연속적으로 그리고 광범위하게 일어났고 있음을 의미한다. 하루 최고 오존 농도는 일사량, 최고 온도와 양의 상관을 보였으며, 상대 습도, 풍속, 구름양과는 음의 상관을 보였다. 일사량과의 상관계수가 0.45로 가장 높았다. 고농도 오존 발생 일의 기상 값과 그 날을 포함하는 월평균 값과의 차이를 보면, +1.58hPa(해면 기압), +3.45${\circ}$C(최고 기온), -5.69%(상대 습도), -0.46ms$^{-1}$(풍속), -1.79(구름양), +3.97MJm$^{-2}$(일사량)을 각각 보였다. 이는 0700${\sim}$1100LST사이의 높은 일사량, 낮은 풍속, 무강수가 고농도 예측의 중요특징임을 나타낸다. 이는 이 시간의 정체와도 연관이 있다.

• Journal of Korean Neurosurgical Society
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• 제62권5호
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• pp.561-566
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• 2019

Objective : Functional outcomes have traditionally been evaluated and compared using subjective surveys, such as visual analog scores (VAS), the Oswestry disability index (ODI), and Short Form-36 (SF-36), to assess symptoms and quality of life. However, these surveys are limited by their subjective natures and inherent bias caused by differences in patient perceptions of symptoms. The Fitbit $Charge^{(R)}$ (Fitbit Inc., San Francisco, CA, USA) provides accurate and objective measures of physical activity. The use of this device in patients after laminectomy would provide objective physical measures that define ambulatory function, activity level, and degree of recovery. Therefore, the present study was conducted to identify relationships between the number of steps taken by patients per day and VAS pain scores, prognoses, and postoperative functional outcomes. Methods : We prospectively investigated 22 consecutive patients that underwent laminectomy for spinal stenosis or a herniated lumbar disc between June 2015 and April 2016 by the same surgeon. When patients were admitted for surgery and first visited after surgery, preoperative and postoperative functional scores were recorded using VAS scores, ODI scores, and SF-36. The VAS scores and physical activities were recorded daily from postoperative day (POD) 1 to POD 7. The relationship between daily VAS scores and daily physical activities were investigated by simple correlation analysis and the relationship between mean number of steps taken and ODI scores after surgery was subjected to simple regression analysis. In addition, Wilcoxon's signed-rank test was used to investigate the significance of pre-to-postoperative differences in VAS, ODI, and SF-36 scores. Results : Pre-to-postoperative VAS (p<0.001), ODI (p<0.001), SF-36 mental composite scores (p=0.009), and SF-36 physical composite scores (p<0.001) scores were found to be significantly different. Numbers of steps taken from POD 1 to POD 7 were negatively correlated with daily VAS scores (r=-0.981, p<0.001). In addition, the mean number of steps from POD 3 to POD 7 and the decrease in ODI conducted one month after surgery were statistically significant (p=0.029). Conclusion : Wearable devices are not only being used increasingly by consumers as lifestyle devices, but are also progressively being used in the medical area. This is the first study to demonstrate the usefulness of a wearable device for checking patient physical activity and predicting pain and prognosis after laminectomy. Based on our experience, the wearable device used to provide measures of physical activity in the present study has the potential to provide objective information on pain severity and prognosis.

• 한국인터넷방송통신학회논문지
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• 제8권6호
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• pp.41-48
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• 2008

최근 사회는 의학의 발달과 원인으로 고령인구 비율이 높아지면서 인구의 고령화가 가속화 되고 있다. 하지만 고령인구 비율이 높아지는 것에 그치는 것이 아니라 노인 가구 구성 형태에도 많은 변화를 보여 독거노인이 늘어나면서 독거노인의 여러 가지 많은 사회적인 문제가 발생하고 있다. 한 예로 83세 독거노인이 사망한지 한달 만에 발견되는 등 심각한 수준에 이르렀다. 그리하여 국가적으로 조금이나마 독거노인 생활 확인 서비스를 시행하고 있지만, 현재는 많이 부족한 실정이다. 본 논문에서는 이러한 사회적 상황을 고려하여 ZigBee를 활용한 독거노인 모니터링 시스템을 구현한다. 또한, TinyOS가 탑재된 Moteiv사의 Tmote Sky 센서모트를 사용하여 IEEE 802.15.4 표준기반의 ZigBee 센서 네트워크로 구성하였으며 센서로부터 수신된 환경 정보 데이터를 DB에 저장하여 관리하고 웹페이지 또는 모바일을 통하여 현재 집안의 상태를 모니터링 할수 있도록 하였다.

• International Journal of Fluid Machinery and Systems
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• 제10권2호
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• pp.146-153
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• 2017

Sediment flow through hydropower components causes hydro-abrasive erosion resulting in loss of efficiency, interruptions in power production and downtime for repair/maintenance. Online instruments are required to measure/capture the variations in sediment parameters along with collecting samples manually to analyse in laboratory for verification. In this paper, various sediment parameters viz. size, concentration (TSS), shape and mineral composition relevant to hydro-abrasive erosion were measured and discussed with respect to a hydropower plant in Himalayan region, India. A multi-frequency acoustic instrument was installed at a desilting chamber to continuously monitor particle size distribution (PSD) and TSS entering the turbine during 27 May to 6 August 2015. The sediment parameters viz. TSS, size distribution, mineral composition and shape entering the turbine were also measured and analysed, using manual samples collected twice daily from hydropower plant, in laboratory with instruments based on laser diffraction, dynamic digital image processing, gravimetric method, conductivity, scanning electron microscope, X-ray diffraction and turbidity. The acoustic instrument was able to capture the variation in TSS; however, significant deviations were found between measured mean sediment sizes compared to values found in the laboratory. A good relation was found for turbidity ($R^2=0.86$) and laser diffraction ($R^2=0.93$) with TSS, which indicated that turbidimeter and laser diffraction instrument can be used for continuous monitoring of TSS at the plant. Total sediment load passed through penstock during study period was estimated to be 15,500 ton. This study shall be useful for researchers and hydropower managers in measuring/monitoring sediment for hydro-abrasive erosion study in hydropower plants.

• 한국측량학회지
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• 제36권5호
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• pp.423-432
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• 2018

Surface water mapping has been widely used in various remote sensing applications. Water indices have been commonly used to distinguish water bodies from land; however, determining the optimal threshold and discriminating water bodies from similar objects such as shadows and snow is difficult. Deep learning algorithms have greatly advanced image segmentation and classification. In particular, FCN (Fully Convolutional Network) is state-of-the-art in per-pixel image segmentation and are used in most benchmarks such as PASCAL VOC2012 and Microsoft COCO (Common Objects in Context). However, these data sets are designed for daily scenarios and a few studies have conducted on applications of FCN using large scale remotely sensed data set. This paper aims to fine-tune the pre-trained FCN network using the CRMS (Coastwide Reference Monitoring System) data set for surface water mapping. The CRMS provides color infrared aerial photos and ground truth maps for the monitoring and restoration of wetlands in Louisiana, USA. To effectively learn the characteristics of surface water, we used pre-trained the DeepWaterMap network, which classifies water, land, snow, ice, clouds, and shadows using Landsat satellite images. Furthermore, the DeepWaterMap network was fine-tuned for the CRMS data set using two classes: water and land. The fine-tuned network finally classifies surface water without any additional learning process. The experimental results show that the proposed method enables high-quality surface mapping from CRMS data set and show the suitability of pre-trained FCN networks using remote sensing data for surface water mapping.

• ALGAE
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• 제19권2호
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• pp.145-148
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• 2004

As a result of the 2-year monthly monitoring of the phytoplankton community at 3 stations in Mankyeong Estuary, Korea, we learned that cyan bacterial species of the genus Anabaena occurred at most sampling points with huge salinity differences (0.1-32.5 psu). We isolated several clones of Anabaena spp. from the monitoring stations, and screen out two euryhaline and nitrogen-fixing Anabaena clones, CB-MAL21 and CB-MAL22. The two clones were grown under various environmental gradients such as temperature (20, 30, 35 and 40$^{\circ}C$), salinity (0, 2, 5, 15 and 30psu), and $PO_4^{3-}$-P concentration (0, 1.6, 8.0, 40 and 200 ${\mu}M$M). Growth of CB-MAL21 and CB-MAL22 was measured by daily monitoring of chlorophyll fluorescence from each experimental culture for more than three serial transfers. Both the two experimental clones did not grow at 0psu. Maximal growth rates of the two clones were markedly reduced at lower $PO_4^{3-}$-P concentrations showing negligible growth at 0 and 1.6 ${\mu}M$M. However, growth of CB-MAL21 was not affected by low $NO_3^--$ concentration in culture media, showing the nitrogen-fixing ability. Maximum biomass yields of the two clones decreased dramatically at 35 and 40$^{\circ}C$. Optimal growth conditions for the two experimental clones were determined to be 20-30$^{\circ}C$, 40 ${\mu}M$M $PO_4^{3-}$-P, and wide salinity range from 5.0 to over 30psu. Best growth of CB-MAL21 was shown at (20$^{\circ}C$-15psu), which is less saline and cooler condition than those (i.e., 30$^{\circ}C$-30psu) for the best growth of CB-MAL22. The euryhaline and nitrogen-fixing CB-MAL21 strain thus can be a candidate laboratory culture for the future cyan bacterial marine biotechnology in temperate coastal waters.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.237-240
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• 2005

Calibration and Validation are major element of any space borne Earth Observation Mission. These activities are the major objective of the commissioning phases but routine activities shall be maintained during the whole mission in order to maintain the quality of the product delivered to the users or at least to fully characterise the evolution with time of the product quality. With the launch of ERS-l in 1991, the European Space Agency decided to put in place a group dedicated to these activities, along with the daily monitoring of the product quality for anomaly detection and algorithm evolution. These four elements are all strongly linked together. Today this group is fully responsible for the monitoring of two ESA missions, ERS-2 and Envisat, for a total of 12 instruments of various types, preparing itself for the Earth Explorer series of five. other satellites (Cryosat, Goce, SMOS, ADM-Aeolus, Swarm) and at various levels in past and future Third Party Missions such as Landsat, J-ERS, ALOS and KOMPSAT. The Joint proposal by the European Union and the European Space Agency for a 'Global Monitoring for Environment and Security' project (GMES), triggers a review of the scope of these activities in a much wider framework than the handling of single missions with specific tools, methods and activities. Because of the global objective of this proposal, it is necessary to put in place Multi-Mission Calibration and Validation systems and procedures. GMES Calibration and Validation activities will rely on multi source data access, interoperability, long-term data preservation, and definition standards to facilitate the above objectives. The scope of this presentation is to give an overview of the current Calibration and Validation activities at ESA, and the planned evolution in the context of GMES.