• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.12 no.4
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• pp.315-327
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• 2007

This study investigated temporal and spatial variation of Pb and stable Pb isotopes accumulated in Ulleung Basin core sediments (4) using MC ICP/MS in order to identify the sources of anthropogenic Pb in the East/Japan Sea. Leached (1M HCl) Pb concentration and isotope ratios ($^{207}Pb/^{206}Pb\;and\;^{208}Pb/^{206}Pb$) were nearly constant during 300 yrs past than 1930, but increased up to twice in concentration and as much as 3.41% (1.70%) after 2000. On the other hand, residual Pb concentrations were nearly constant for past 400 yrs. The accumulation rates of anthropogenic Pb in the basin area were in the range of $3.1-3.5mg/m^2/yr$, which were similar levels to total atmospheric Pb deposition fluxes from 1990s to the present. In the slope area, more increase of anthropogenic Pb accumulation than the levels expected from mass accumulation rate could be found after the middle of 1990s. From the detailed evaluation for the temporal and spatial variation of accumulation rate and isotope ratios of anthropogenic Pb, we proposed probable sources and pathways of anthropogenic Pb. Pb emmision by coal burning from the China and Korea initiated the accumulation of anthropogenic Pb in the sediments of East/Japan Sea from 1930s. The accumulation of Pb increased by the addition of anti-nocking agents from both countries untill the beginning of 1990s, but from the middle of 1990s to the present, the phase-out of gasoline additives and the rapid increase of coal burning from the China maintained the atmospheric Pb levels in the Ulleung basin nearly similar to before. However, the local sources within this basin might take an important role in the rapid increase of anthropogenic Pb accumulation in slope areas from the middle of 1990s.

• Korean Journal of Organic Agriculture
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• v.19 no.2
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• pp.255-272
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• 2011

This work studied the growth and yield of green crops, changes of mineral composition in greenhouse soil and green crops, and infection with wintering green crops cultivation in greenhouse field. At 74 days after seeding of wintering green crops, dry matter was 710kg/10a in rye, 530kg/10a in barley, 230kg/10a in hairy vetch, and 240kg/10a in bean or weeds. Total nitrogen content in green crops was 4.5% in pea and hairy vetch, and 3~4% in barley and rye. $P_2O_5$, CaO, and MgO contents in all green crops were about 1.0%, and $K_2O$ content was the highest level by 4~5% among macro elements. Total nitrogen fixing content in shoot green crops uptaken from soil was 22.1kg/10a in rye, 20.6kg/10a in barley, 10.6kg/10a in hairy vetch, and 9.6kg/10a in pea and giant chickweed. $P_2O_5$ fixing content in shoot green crops uptaken from soil was 8.4kg/10a in rye, 6.3kg/10a in barley, and 2.3 kg/10a in hairy vetch and pea. $K_2O$ fixing content in shoot green crops uptaken from soil was 28kg/10a in rye, 24.7kg/10a in barley, and 11kg/10a in hairy vetch and pea. CaO fixing content in shoot green crops uptaken from soil was 2~3kg/ 10a in all green crops, and MgO fixing content was 1.7~2.6kg/10a in all green crops. Pepper growth in no-tillage was not a significant difference at all green manure crops. The number of fruit and fruit weight were higher in control, pea, hairy vetch and harvest barley than rye and barley. Soil mineral compositions in wintering green crops increased at pH, organic matter, CEC compared with control. Soil chemical compositions were stable level at green crops cultivation according as decreases of EC, available phosphoric acid, Ca, and Mg contents. After no-tillage by green manure crops, pH in soils was higher in green manure crops than control. EC content in soils was lower in green manure crops than control, and was remarkably low level in barley harvest. Organic matter content in soils increased in hairy vetch and barley green manure but decreased by 35% in barley harvest. Total nitrogen and avaliable $P_2O_4$ content in soils remarkably increased but was not a significant difference at all green manure crops. Cation (K, Ca, and Mg) content in soils decreased by 15~20% in K, 2~11% in Ca, and 3~6% in Mg at rye, barley and pea compared with control.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.4
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• pp.144-159
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• 2014

Techniques for making a single panoramic image using multiple pictures are widely studied in many areas such as computer vision, computer graphics, etc. The panorama image can be applied to various fields like virtual reality, robot vision areas which require wide-angled shots as an useful way to overcome the limitations such as picture-angle, resolutions, and internal informations of an image taken from a single camera. It is so much meaningful in a point that a panoramic image usually provides better immersion feeling than a plain image. Although there are many ways to build a panoramic image, most of them are using the way of extracting feature points and matching points of each images for making a single panoramic image. In addition, those methods use the RANSAC(RANdom SAmple Consensus) algorithm with matching points and the Homography matrix to transform the image. The SURF(Speeded Up Robust Features) algorithm which is used in this paper to extract featuring points uses an image's black and white informations and local spatial informations. The SURF is widely being used since it is very much robust at detecting image's size, view-point changes, and additionally, faster than the SIFT(Scale Invariant Features Transform) algorithm. The SURF has a shortcoming of making an error which results in decreasing the RANSAC algorithm's performance speed when extracting image's feature points. As a result, this may increase the CPU usage occupation rate. The error of detecting matching points may role as a critical reason for disqualifying panoramic image's accuracy and lucidity. In this paper, in order to minimize errors of extracting matching points, we used $3{\times}3$ region's RGB pixel values around the matching points' coordinates to perform intermediate filtering process for removing wrong matching points. We have also presented analysis and evaluation results relating to enhanced working speed for producing a panorama image, CPU usage rate, extracted matching points' decreasing rate and accuracy.

• Tunnel and Underground Space
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• v.30 no.3
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• pp.256-269
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• 2020

The objective of this study is to evaluate the stress thresholds in crack development and the corrected fracture toughness of KURT granite under dry and saturated conditions. The stress thresholds were identified by calculation of inelastic volumetric strain from an uniaxial compression test. The corrected fracture toughness was estimated by using the Level II method (Chevron Bend specimen), suggested by ISRM (1988), in which non-linear behaviors of rock was taken into account. Average crack initiation stress(σ_ci) and crack damage stress(σ_cd) under a dry condition were 91.1 MPa and 128.7 MPa. While, average crack initiation stress(σ_ci) and crack damage stress(σ_cd) under a saturated condition were 58.2 MPa and 68.2 MPa. The crack initiation stress and crack damage stress of saturated ones decreased 36% and 47% respectively compared to those of dry specimens. A decrease in crack damage stress is relatively larger than that of crack initiation stress under a saturated condition. This indicates that the unstable crack growth can be more easily generated because of the saturation effect of water compared to the dry condition. The average corrected fracture toughness of KURT granite was 0.811 MPa·m^0.5. While, the fracture toughness of saturated KURT granite(K_CB) was 0.620 MPa·m^0.5. The corrected fracture toughness of rock in saturated condition decreases by 23.5% compared to that in dry condition. It is found that the resistance to crack propagation decreases under the saturated geological condition.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.5
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• pp.455-461
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• 2002

limiting nutrients for phytoplankton were determined by dissored inorganic nitrogen/phosphorous (DIN/DIP) in situ and algal bioassay experiment in the Seomjin River estuary during a study period from March 1999 to October 2001. DIN/DIP ranged from 14.7 to 681.1 during the study period. DIN/DIP was over 16 at the upper and middle estuarine region where salinity was lower than 25 psu and chlorophyll a concentration was high, probably indicating P-limitation in this region while the ratio was less than 16 at the high saline (> 25 psu) region, reflecting the supply of DIP from Gwangyang Bay and thereby indicating N-limitation at the lower estuarine region. These results suggested that the spatial distribution of DIN/DIP in the study region was controlled by the high supply of phosphate from Gwangyang Bay, the low input from Seomjin River and the active uptake by phytoplankton within the estuarine system. The bioassay experiments using Skeletonema costatum, Thalaasiosira rotula and in situ phytoplankton assemblage displayed relatively higher growth of phytoplankton in the P-added culture media, indicating P-limitation. This result was well consistent with the spatial distribution of inorganic nutrients. S. costatum showed a rapid adaptation to the low salinity compared to other phytoplankton species. This phenomenon seemed to account for the strong (> $90\%$ in total cell number) S. costatum bloom in autumn in this estuary. Moreover, although phytoplankton growth rate was higher in the P-added culture media at the end of culture experiment of in situ phytoplankton, the fast growth in the trace metal-added media at the beginning of the experiment suggested a possibility of limitation by other micro-nutrients such as trace metal and vitamin etc.

• The Korean Journal of Nuclear Medicine Technology
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• v.25 no.2
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• pp.29-34
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• 2021

Purpose Sample reception environment system in nuclear medicine has not changed much compared to 20 years ago. When preparing sample for in vitro test, there was no significant change because the test was carried out by generating an own specimen from the parent specimen. In this study, We would like to introduce a method that automatically removes the sample cap using the automated decapper equipment and enables automatic reception at the same time. In addition, including a provisional reception system. Materials and Methods In 2019, it was intended to get a device that automatically removes the cap of a patient's blood sample. This equipment is the same as the equipment used in the Department of Laboratory Medicine (Vacuette Ⓡ Unicap Belt Decapper, Greiner bio-one, Austria). However, the purchase was delayed due to differences in tube size, budget, and space. In January 2020, we borrowed domestic automatic decapper equipment and modified it to suit our laboratory environment. After 9 months, we were able to introduce a system that automatically removes the lid of a patient's blood sample and at the same time automatically accepts the test. And, through the provisional reception system, it was possible to know the arrival of the specimen in a short time. Results With the use of an automatic decapper device, the sample cap was automatically removed, and the reception proceeded at the same time. So, it was very efficient at work because it shortened the sample preparation time by about 20 minutes. In addition, it was possible to prevent the examiner's musculoskeletal disorders caused by repeated wrist use. After using the provisional reception system, patients were able to be discharged quickly, and the number of phone calls to confirm the arrival of samples was reduced. Conclusion Most hospitals have about four employees in the nuclear medicine in vitro laboratory. It is effective to use automatic decapper equipment and a provisional reception system for organizations that perform work with the minimum number of personnel.

• Journal of Bio-Environment Control
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• v.31 no.4
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• pp.485-496
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• 2022

Modern agriculture is being transformed into smart agriculture to maximize production efficiency along with changes in the 4th industrial revolution. However, rural areas in Korea are facing challenges of aging, low fertility, and population outflow, making it difficult to transition to smart agriculture. Among ICT technologies, simulation allows users to observe or experience the results of their choices through imitation or reproduction of reality. The combination of the three-dimension (3D) model and the greenhouse simulator enable a 3D experience by virtual greenhouse for fruits and vegetable cultivation. At the same time, it is possible to visualize the greenhouse under various cultivation or climate conditions. The objective of this study is to apply the greenhouse climate management model for simulation development that can visually see the state of the greenhouse environment under various micrometeorological properties. The numerical solution with the mathematical model provided a dynamic change in the greenhouse environment for a particular greenhouse design. Light intensity, crop transpiration, heating load, ventilation rate, the optimal amount of CO₂ enrichment, and daily light integral were calculated with the simulation. The results of this study are being built so that users can be linked through a web page, and software will be designed to reflect the characteristics of cladding materials and greenhouses, cultivation types, and the condition of environmental control facilities for customized environmental control. In addition, environmental information obtained from external meteorological data, as well as recommended standards and set points for each growth stage based on experiments and research, will be provided as optimal environmental factors. This simulation can help growers, students, and researchers to understand the ICT technologies and the changes in the greenhouse microclimate according to the growing conditions.

• Korean Journal of Remote Sensing
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• v.39 no.5_1
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• pp.481-493
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• 2023

In high-density urban areas, the urban heat island effect increases urban temperatures, leading to negative impacts such as worsened air pollution, increased cooling energy consumption, and increased greenhouse gas emissions. In urban environments where it is difficult to secure additional green spaces, rooftop greening is an efficient greenhouse gas reduction strategy. In this study, we not only analyzed the current status of the urban heat island effect but also utilized high-resolution satellite data and spatial information to estimate the available rooftop greening area within the study area. We evaluated the mitigation effect of the urban heat island phenomenon and carbon sequestration capacity through temperature predictions resulting from rooftop greening. To achieve this, we utilized WorldView-2 satellite data to classify land cover in the urban heat island areas of Busan city. We developed a prediction model for temperature changes before and after rooftop greening using machine learning techniques. To assess the degree of urban heat island mitigation due to changes in rooftop greening areas, we constructed a temperature change prediction model with temperature as the dependent variable using the random forest technique. In this process, we built a multiple regression model to derive high-resolution land surface temperatures for training data using Google Earth Engine, combining Landsat-8 and Sentinel-2 satellite data. Additionally, we evaluated carbon sequestration based on rooftop greening areas using a carbon absorption capacity per plant. The results of this study suggest that the developed satellite-based urban heat island assessment and temperature change prediction technology using Random Forest models can be applied to urban heat island-vulnerable areas with potential for expansion.

• Journal of Intelligence and Information Systems
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• v.24 no.1
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• pp.25-52
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• 2018

This study performs social network analysis based on consumer sentiment related to a location in Seoul using data reflecting consumers' web search activities and emotional evaluations associated with commerce. The study focuses on large commercial districts in Seoul. In addition, to consider their various aspects, social network indexes were combined with the trading area's public data to verify factors affecting the area's sales. According to R square's change, We can see that the model has a little high R square value even though it includes only the district's public data represented by static data. However, the present study confirmed that the R square of the model combined with the network index derived from the social network analysis was even improved much more. A regression analysis of the trading area's public data showed that the five factors of 'number of market district,' 'residential area per person,' 'satisfaction of residential environment,' 'rate of change of trade,' and 'survival rate over 3 years' among twenty two variables. The study confirmed a significant influence on the sales of the trading area. According to the results, 'residential area per person' has the highest standardized beta value. Therefore, 'residential area per person' has the strongest influence on commercial sales. In addition, 'residential area per person,' 'number of market district,' and 'survival rate over 3 years' were found to have positive effects on the sales of all trading area. Thus, as the number of market districts in the trading area increases, residential area per person increases, and as the survival rate over 3 years of each store in the trading area increases, sales increase. On the other hand, 'satisfaction of residential environment' and 'rate of change of trade' were found to have a negative effect on sales. In the case of 'satisfaction of residential environment,' sales increase when the satisfaction level is low. Therefore, as consumer dissatisfaction with the residential environment increases, sales increase. The 'rate of change of trade' shows that sales increase with the decreasing acceleration of transaction frequency. According to the social network analysis, of the 25 regional trading areas in Seoul, Yangcheon-gu has the highest degree of connection. In other words, it has common sentiments with many other trading areas. On the other hand, Nowon-gu and Jungrang-gu have the lowest degree of connection. In other words, they have relatively distinct sentiments from other trading areas. The social network indexes used in the combination model are 'density of ego network,' 'degree centrality,' 'closeness centrality,' 'betweenness centrality,' and 'eigenvector centrality.' The combined model analysis confirmed that the degree centrality and eigenvector centrality of the social network index have a significant influence on sales and the highest influence in the model. 'Degree centrality' has a negative effect on the sales of the districts. This implies that sales decrease when holding various sentiments of other trading area, which conflicts with general social myths. However, this result can be interpreted to mean that if a trading area has low 'degree centrality,' it delivers unique and special sentiments to consumers. The findings of this study can also be interpreted to mean that sales can be increased if the trading area increases consumer recognition by forming a unique sentiment and city atmosphere that distinguish it from other trading areas. On the other hand, 'eigenvector centrality' has the greatest effect on sales in the combined model. In addition, the results confirmed a positive effect on sales. This finding shows that sales increase when a trading area is connected to others with stronger centrality than when it has common sentiments with others. This study can be used as an empirical basis for establishing and implementing a city and trading area strategy plan considering consumers' desired sentiments. In addition, we expect to provide entrepreneurs and potential entrepreneurs entering the trading area with sentiments possessed by those in the trading area and directions into the trading area considering the district-sentiment structure.

• Tuberculosis and Respiratory Diseases
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• v.64 no.6
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• pp.433-438
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• 2008

Background: Measurement of the maximum oxygen uptake in patients with chronic obstructive pulmonary disease (COPD) has been used to determine the intensity of exercise and to estimate the patient's response to treatment during pulmonary rehabilitation. However, cardiopulmonary exercise testing is not widely available in Korea. The 6-minute walk test (6MWT) is a simple method of measuring the exercise capacity of a patient. It also provides high reliability data and it reflects the fluctuation in one' s exercise capacity relatively well with using the standardized protocol. The prime objective of the present study is to develop a regression equation for estimating the peak oxygen uptake ($VO_2$) for men with moderate to very severe COPD from the results of a 6MWT. Methods: A total of 33 male patients with moderate to very severe COPD agreed to participate in this study. Pulmonary function testing, cardiopulmonary exercise testing and a 6MWT were performed on their first visits. The index of work ($6M_{work}$, 6-minute walk distance [6MWD]${\times}$body weight) was calculated for each patient. Those variables that were closely related to the peak $VO_2$ were identified through correlation analysis. With including such variables, the equation to predict the peak $VO_2$ was generated by the multiple linear regression method. Results: The peak $VO_2$ averaged $1,015{\pm}392ml/min$, and the mean 6MWD was $516{\pm}195$ meters. The $6M_{work}$ (r=.597) was better correlated to the peak $VO_2$ than the 6MWD (r=.415). The other variables highly correlated with the peak $VO_2$ were the $FEV_1$ (r=.742), DLco (r=.734) and FVC (r=.679). The derived prediction equation was $VO_2$ (ml/min)=($274.306{\times}FEV_1$)+($36.242{\times}DLco$)+($0.007{\times}6M_{work}$)-84.867. Conclusion: Under the circumstances when measurement of the peak $VO_2$ is not possible, we consider the 6MWT to be a simple alternative to measuring the peak $VO_2$. Of course, it is necessary to perform a trial on much larger scale to validate our prediction equation.