• Journal of Soil and Groundwater Environment
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• v.14 no.5
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• pp.41-50
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• 2009

Water levels in groundwater monitoring wells of Jeju Island were analyzed using parametric and non-parametric trend analyses. Number of used monitoring wells in the analysis are 94 among totally 106 monitoring wells and the monitoring period is greater than single year, from 2001 to 2009. For the trend analysis, both parametric (linear regression) and nonparametric (Mann-Kendall trend test and Sen's trend test) methods were adopted. Results of the linear regression analysis on daily basis indicated that about 58.5% of the monitoring wells showed a decreasing trend, and analysis using monthly median indicated that about 79.8% showed a decreasing trend. The Mann-Kendall trend test and Sen's trend test with monthly median values in confidence levels of 95% and 99% showed the same analysis results. In confidence level of 95%, 32% were decreased, 3% were increased and the remains showed no trend. However, in confidence level of 99%, 16% were decreased, 2% were increased and the remains showed no trend. The largest decline rates of water levels were detected mainly at the coast of the northwestern and southwestern parts, which is expected to closely related to the increased pumping in the urban area and tourist resort.

• The Korean Journal of Pesticide Science
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• v.19 no.1
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• pp.32-40
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• 2015

This study was implemented to evaluate food safety on residual pesticides in agricultural products of Korea and to use as a data base for the establishment of food policy. A total of 196 pesticide upon these products were analyzed using multi class pesticide multiresidue methods of Korean Food Code, and 232 samples of 15 agricultural products collected from 9 regions were supplied for this study. In the results, 64 kinds of pesticides were detected in 53 samples, chlorpyrifos and procymidone of them were shown a high frequency of detection in the analyzed pesticides. Among them, two samples (chlorpyrifos in perilla leaves and picoxystrobin in peach) were detected over Maximum Residue Limits (MRLs). The levels of the detected pesticide residues were within safe levels. Also, the intake assessment for pesticide residues including chlorpyrifos at multi pesticide residue monitoring were carried out. The result showed that the ratio of EDI (estimated daily intake) to ADI (acceptable daily intake) was 0.001~0.902% which means that the detected pesticide residues were in a safe range so that residual pesticides in the agricultural products in Korea are properly controlled.

• Journal of Environmental Health Sciences
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• v.33 no.5
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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.

• Journal of the Korean earth science society
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• v.23 no.5
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• pp.424-435
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• 2002

This study analyzes the surface ozone and meteorological data in Daegu for a period from 1997 to 1999. It also investigates the meteorological characteristics of high ozone episodes. For this study the high ozone episode has been defined as a daily maximum ozone concentration higher than 100ppb in at least one station among six air quality monitoring stations in Daegu, Korea. The frequency of episodes is 13 days. The frequency is the highest in May and September. The average value of daily maximum ozone concentration is 81.6ppb, and 8-hour average ozone concentration is 58.6ppb for the high episodes. This shows that ozone pollution is continuous and wide-ranging in Daegu. The daily maximum ozone concentration is positively correlated to solar radiation and daily maximum temperature, but negatively correlated to relative humidity, wind speed and cloud amount. The maximal correlation coefficient to solar radiation is 0.45. The differences between high ozone episode day's daily mean meteorological value and monthly mean value are +1.58hPa for sea level pressure, +3.45${\circ}$C for maximum temperature, -5.69% for relative humidity, -0.46ms$^{-1}$ for wind speed, -1.79 for cloud amount, and +3.97MJm$^{-2}$ for solar radiation, respectively. This shows that strong solar radiation, low wind speed and no precipitation between 0700${\sim}$1100LST are favorite conditions for high ozone episodes. It is related to the morning stagnant condition.

• Journal of Korean Neurosurgical Society
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• v.62 no.5
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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.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.8 no.6
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• pp.41-48
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• 2008

The realization of a monitoring system for senior citizens living alone through wireless sensor network. Due to the recent advances in medical science, people live longer than ever before which accelerates the number of senior citizens. The high rate of the old people in population causes some changes in the form of families, which results in the increasing number of old people living by themselves. This also causes a lot of social problems concerning aging population. For example, people found a dead body of 83-year-old, who had lived alone, after he passed away a month before. There is a national monitoring service for the old people of their daily lives, but the application of such system is very limited. Considering this, the current paper focuses on the realization of a monitoring system for senior citizens living alone through wireless sensor network. The system consists of ZigBee sensor network, which is based on standard IEEE 802.15.4. and the system uses Tmote Sky sensor mote made by Moteive, which is installed with TinyOS. The circumstances information data will be saved on DB and a household will be monitored through a Webpage or Mobile.

• International Journal of Fluid Machinery and Systems
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• v.10 no.2
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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.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.36 no.5
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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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• v.19 no.2
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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.

• Proceedings of the KSRS Conference
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• 2005.10a
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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.