• Journal of Korean Society of Forest Science
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• v.96 no.1
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• pp.7-13
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• 2007

This study was done to develop PDA based application system for forest geographic information with GPS. The major results obtained in this study were as follows. A PDA based application program was developed to work on $Microsoft^{TM}$ PocketPC 2002 and 2003 operating system. The screen of PDA displays a 1:25,000 digital topographical map adopted DXF format converted from PC, and the map data with 1:2,500 to 1:30,000 on PDA can be zoomed in or out to five levels. Current position and navigating path received from GPS can be displayed on the screen and be saved in PDA. Information selected among layers of digital topographic map in DXF format can be converted into binary files which can be used on forest geographic information software. This can compress DXF files to 90% in size, and the processing speed of PDA was improved. The forest geographic information management system can be used to manage sample plots on which forest inventory is done, with the help of the sub-menus and grid index values with position information received from GPS. Forest workers can in quire forest geographic information such as forest type, location, forest roads, soil erosion control dams using forest geographic information management system in the field. The forest geographic information management system can provide current position and mobile path information to people who enjoy forest related activities like mountain-climbing, sightseeing, and visiting to historic spots.

• Korean Journal of Remote Sensing
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• v.38 no.6_2
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• pp.1723-1735
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• 2022

Landslides are one of the most prevalent natural disasters, threating both humans and property. Also landslides can cause damage at the national level, so effective prediction and prevention are essential. Research to produce a landslide susceptibility map with high accuracy is steadily being conducted, and various models have been applied to landslide susceptibility analysis. Pixel-based machine learning models such as frequency ratio models, logistic regression models, ensembles models, and Artificial Neural Networks have been mainly applied. Recent studies have shown that the kernel-based convolutional neural network (CNN) technique is effective and that the spatial characteristics of input data have a significant effect on the accuracy of landslide susceptibility mapping. For this reason, the purpose of this study is to analyze landslide vulnerability using a pixel-based deep neural network model and a patch-based convolutional neural network model. The research area was set up in Gangwon-do, including Inje, Gangneung, and Pyeongchang, where landslides occurred frequently and damaged. Landslide-related factors include slope, curvature, stream power index (SPI), topographic wetness index (TWI), topographic position index (TPI), timber diameter, timber age, lithology, land use, soil depth, soil parent material, lineament density, fault density, normalized difference vegetation index (NDVI) and normalized difference water index (NDWI) were used. Landslide-related factors were built into a spatial database through data preprocessing, and landslide susceptibility map was predicted using deep neural network (DNN) and CNN models. The model and landslide susceptibility map were verified through average precision (AP) and root mean square errors (RMSE), and as a result of the verification, the patch-based CNN model showed 3.4% improved performance compared to the pixel-based DNN model. The results of this study can be used to predict landslides and are expected to serve as a scientific basis for establishing land use policies and landslide management policies.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.238-238
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• 2015

There are demands for water environmental analysis of discharge processes in paddy fields, however, it is not fully understood in nutrients discharge process for watershed modeling. As hydrological processes both surface and ground water and agricultural water managements are so complex in paddy fields, the development of lowland paddy fields watershed model is more difficult than upland watershed model. In this research, the improvement of SWAT (Soil and Water Assessment Tool) model for a paddy watershed was conducted. First, modification of surface inundated process was developed in improved pot hole option. Those modification was evaluated by monitoring data. Second, the monitoring data in river and drainage channel in lowland paddy fields from 2012 to 2014 were analyzed to understand discharge characteristics. As a case study, Imbanuma basin, Japan, was chosen as typical land and water use in Asian countries. In this basin, lowland paddy fields are irrigated from river water using small pumps that were located in distribution within the watershed. Daily hydrological fluctuation was too complex to estimate. Then, to understand surface and ground water discharge characteristics in irrigation (Apr-Aug) and non-irrigation (Sep-Mar) period, the water and material balance analysis was conducted. The analysis was composed two parts, watershed and river channel blocks. As results of model simulation, output was satisfactory in NSE, but uncertainty was large. It would be coming from discharge process in return water. The river water and ground water in paddy fields were exchanged each other in 5.7% and 10.8% to river discharge in irrigation and non-irrigation periods, respectively. Through this exchange, nutrient loads were exchanged between river and paddy fields components. It suggested that discharge from paddy fields was not only responded to rainfall but dynamically related with river water table. In general, hydrological models is assumed that a discharge process is one way from watershed to river. However, in lowland paddy fields, discharge process is dynamically changed. This function of paddy fields showed that flood was mitigated and temporally held as storage in ground water. Then, it showed that water quality was changed in mitigated function in the water exchange process in lowland paddy fields. In future, it was expected that hydrological models for lowland paddy fields would be developed with this mitigation function.

• Food Science and Preservation
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• v.16 no.4
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• pp.459-462
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• 2009

'Fuyu' (Diospyros kaki L.) is an important sweet persimmon cultivar, and the fruits are often stored in a modified atmosphere after harvesting in South Korea. However, blossom-end browning and darkening of fruit often occur after harvest or during storage, which decreases fruit quality in the fresh fruit market. High fruit calcium concentration would reduce oxidation of phenolic compounds in the cytoplasm such oxidation is responsible for fruit browning. This study investigated the effects of soluble calcium fertilization and foliar application, and indole-3-butyric acid (IBA) fertilization on fruit quality and browning. Trees received one of the following five treatments: 1) control (no calcium or IBA); 2) calcium fertilization (Ca FG, 2 mL per tree); 3) calcium foliar application (Ca FA, 2 mL); 4) calcium and IBA fertilization (Ca+IBA) 5) IBA fertilization (IBA, 2 mL. Fruit calcium concentration was highest in trees treated by Ca FA, and lowest in control trees. Generally, fruit calcium concentration was high in the stem end but low in the blossom end, which usually first develops fruit-browning symptoms. There were no apparent differences in fruit qualities such as firmness, soluble solid content, and weight among treatments. Fruit browning occurred at frequencies of about 14%, 20%, and 50% on Ca FA, Ca FG, and control trees, respectively. Therefore, the improved fruit calcium level seen when trees received Ca or IBA application tended to prevent fruit browning, which increased fruit quality and storage properties.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.1
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• pp.18-28
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• 2021

The growth period and productivity of cropping system of winter wheat-rice, winter wheat-bean and winter wheat-grain corn for 4 years from 2015 to 2018 were compared at the experimental field of National Institute of Crop Science in Miryang city. The harvest period of winter wheat was in mid-June, and summer crops were sown (transplanted) in late June. In transplanting of rice in late June, there was no difficulty in securing the heading of panicle and the yield of rice, but there was a lot of trouble in sowing wheat in proper time because the harvest time of rice was delayed to early November due to late maturity of rice, particularly in the mid-late maturing cultivar. There was no problem in soybean planting after winter wheat because the proper period of soybean planting is late-June. In addition, there was no problem in winter wheat sowng after soybean because the maturity period of soybean was mid-October. Selection of grain maize in double cropping with winter wheat in terms of growing periods, was desirable because grain maize had the fastest maturity among summer crops. In double cropping of winter wheat-summer crops, wheats combined with soybean and grain maize showed stable yields during three years, but there was a risk of yield declines in the wheat combined with rice in heavy rainfall year. It was possible to secure high yields in three summer crops as yields of rice, soybean, and corn were 600, 350, and 800 kg/10a, respectively. Summer crops with medium maturity was recommended because of no significant difference in yield between medium maturity and medium-late maturity cultivar. Soil physical properties were improved in soils cultivated with soybean and grain maize. Therefore, It was thought that double cropping systems of winter wheat with soybean and grain maize were superior to that of winter wheat with rice in terms of connecting period between winter wheat - summer crops and improvement of soil physical properties, and total income, particularly in soybean.

• Journal of The Korean Society of Grassland and Forage Science
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• v.26 no.2
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• pp.69-76
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• 2006

To optimize tissue culture responses for genetic transformation of Kentucky bluegrass, the effects of culture medium supplements on tissue culture responses were investigated with mature seeds of a cultivar 'Newport' as explant tissues. The optimal concentration of 2,4-D (2.4-dichloro phenoxy acetic acid) for the induction of embryogenic callus from mature seed was 3 mg/L. Plant regeneration frequency was 54% when embryogenic callus was cultured on the regeneration medium supplemented with 1 mg/L 2,4-D and 3 mg/L of BA (6-benzyladenine). Addition of 1 g/L of casein hydrolysate and 500 mg/L of L-proline improved frequencies of embryogenic callus induction and plant regeneration up to 60.8% and 58.3%, respectively. Regenerated plants were grown normally when shoots transplanted to the soil. A rapid and efficient plant regeneration system established in this study. We suggest that the results may be useful for molecular breeding of Kentucky bluegrass through genetic transformation.

• Korean Journal of Medicinal Crop Science
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• v.7 no.2
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• pp.94-100
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• 1999

To establish the mass propagation system of Lavandula spica cv. Marino, shoot tip, node, internode and leaf segment cultures were carried out. RAPD was applied to detect the somaclonal variation. Callus induction was very high in the medium supplemented with 1 mg/l 2.4-D, 2 mg/l NAA. especially and combined with 0.05 mg/l BAP from leaves. Shoot formation was high with $2{\sim}4\;mg/l$ BAP or 4 mg/l BAP + 0.2 mg/l NAA from shoot tip. Shoot proliferation was 9.1 times in the $B_{5}$ medium with 0.5 mg/l BAP and 0.01 mg/l NAA. Root formation was improved in NAA, which was the concentration of 0.1 to 1 mg/l and 1 mg/l IAA. Nursery survival rate was enhanced over 90% and growth was looked good in the acclimation soil consisting of peatmoss : vermiculite : perlite (1:1:1, v:v:v). Randomly amplified polymorphic DNA banding patterns based on polymerase chain reaction (PCR) were used to assess the genetic variation in plants regenerated from in vitro culture.

• Weed & Turfgrass Science
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• v.6 no.3
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• pp.272-281
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• 2017

This study was conducted to evaluate the effect of liquid fertilizer containing humic acid (LFHA) on changes of creeping bentgrass quality and growth. Treatments were designed as follows; control fertilizer (CF), HA-1 ($CF+1ml\;m^{-2}LFHA$ LFHA), HA-2 ($CF+2ml\;m^{-2}LFHA$ LFHA), and HA-3 ($CF+4ml\;m^{-2}LFHA$). As compared with CF, soil chemical properties and chlorophyll content of clipping of LFHA treatments were not significantly different. Visual quality in both of HA-2 and HA-3 treatments was higher than that of CF treatment from September to November, and clipping yield on October 27. Shoot density, root length, and the content of nitrogen, phosphorus or potassium were increased by application of LFHA. The clipping yield was positively correlated with phosphorus content, potassium content or shoot density. Similarly, LFHA level was proportionate to clipping yield of creeping bentgrass, and N, P, K contents in the leaf tissue. These results generally demonstrated that the application of LFHA improved the growth and quality of creeping bentgrass by increase of N content or P in leaf tissue.

• Weed & Turfgrass Science
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• v.5 no.3
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• pp.170-176
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• 2016

Superintendents have used a silicate fertilizer to improve a resistance of turfgrass against several diseases, drought damage and wear stress. This study was conducted to evaluate the effect of liquid fertilizer containing silicate (LFSi) on changes of turfgrass quality and growth by investigating visual quality, chlorophyll content-chlorophyll a, chlorophyll b, and total chlorophyll, root length, shoot length, dry weight of clipping, and nutrient content in leaves tissue. Treatments were designed as follows; control fertilizer (CF), SiF-1 (CF + $1ml\;m^{-2}$ LFSi), SiF-2 (CF + $2ml\;m^{-2}$ LFSi), and SiF-3 (CF + $4ml\;m^{-2}$ LFSi). As compared with CF, soil chemical properties, visual turfgrass quality, chlorophyll content, and dry weight of clipping of LFSi treatments were not significantly. Contrastingly, shoot density, root length, and the content of nitrogen or potassium were increased by application of LFSi. The content of Si in the tissue was positively correlated with potassium content or shoot length, and similarly shoot density positively with chlorophyll content or visual quality, respectively. These results suggested that the application of LFSi improved the turfgrass quality by increasing shoot density or K content in leaf tissue of creeping bentgrass.

• Journal of the Korean Geotechnical Society
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• v.23 no.2
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• pp.47-60
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• 2007

Conventional active surface wave measurements performed using a transient or continuous source are often limited in the maximum depth of penetration due to the difficulty of generating low-frequency energy with reasonably portable sources. This limitation may inhibit accurate seismic site response calculations because of the inability to define deeper subsurface structure. By measuring surface wave generated by passive sources including microtremors and cultural noise, it is possible to overcome this problem and develop soil stiffness profiles to much larger depth. Reliability of dispersion estimates from the passive surface wave measurements is critical to present reliable shear wave velocity profiles and can be improved by the measurements and analyses of passive surface waves based on correct understanding of systematic errors included in passive dispersion data. In this study, the systematic errors caused by poor wavenumber resolution and energy leakage into sidelobes in passive tests are mainly explored. Recommendations for reliable passive surface wave measurements and dispersion estimates are presented and illustrated at a site in San Jose, California, U.S.