• Korean Journal of Remote Sensing
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• v.23 no.6
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• pp.559-566
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• 2007

The generation of precise digital elevation model (DEM) is very important in coastal area where time series are especially required. Although a LIDAR system is useful in coastal regions, it is not yet popular in Korea mainly because of its high surveying cost and national security reasons. Recently, precise DEM has been made using radar interferometry and waterline methods. One of these methods, spaceborne imaging radar interferometry has been widely used to measure the topography and deformation of the Earth. We acquired ALOS PALSAR FBD mode (Fine Beam Dual) data for evaluating the quality of interferograms and their coherency. We attempted to construct DEM using ALOS PALSAR pairs - One pair is 2007/05/22 and 2007/08/22, another pair is 2007/08/22 and 2007/10/22 with respective perpendicular baseline of 820 m, 312m and respective height sensitivity of 75 m and 185m at southern of Ganghwa tidal flat, Siwha- and Hwaong-lake over west coastal of Korea peninsula. Ganghwa tidal flat has low coherence between 0.3 and 0.5 of 2007/05/22 and 2007/08/22 pair. However, Siwha-lake and Hwaong-lake areas have a higher coherence value (From 0.7 and 0.9) than Ganghwa tidal area. The reason of difference coherence value is tidal condition between tidal flat area (Ganghwa) and reclaimed zone (Siwha-lake and Hwaong-lake). Therefore, DEM was constructed by ALOS PALSAR pair over Siwha-lake and Hwaong-lake. If the temporal baseline is enough short to maintain the coherent phases and height sensitivity is enough small, we will be able to successfully construct a precise DEM over coastal area. From now on, more ALOS PALSAR data will be needed to construct precise DEM of West Coast of Korea peninsular.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.237-237
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• 2015

The district of Marlborough has had more than its share of river management projects over the past 150 years, each one uniquely affecting the geomorphology and flood hazard of the Wairau Plains. A major early project was to block the Opawa distributary channel at Conders Bend. The Opawa distributary channel took a third and more of Wairau River floodwaters and was a major increasing threat to Blenheim. The blocking of the Opawa required the Wairau and Lower Wairau rivers to carry greater flood flows more often. Consequently the Lower Wairau River was breaking out of its stopbanks approximately every seven years. The idea of diverting flood waters at Tuamarina by providing a direct diversion to the sea through the beach ridges was conceptualised back around the 1920s however, limits on resources and machinery meant the mission of excavating this diversion didn't become feasible until the 1960s. In 1964 a 10 m wide pilot channel was cut from the sea to Tuamarina with an initial capacity of $700m^3/s$. It was expected that floods would eventually scour this 'Wairau Diversion' to its design channel width of 150 m. This did take many more years than initially thought but after approximately 50 years with a little mechanical assistance the Wairau Diversion reached an adequate capacity. Using the power of the river to erode the channel out to its design width and depth was a brilliant idea that saved many thousands of dollars in construction costs and it is somewhat ironic that it is that very same concept that is now being used to deal with the aggradation problem that the Wairau Diversion has caused. The introduction of the Wairau Diversion did provide some flood relief to the lower reaches of the river but unfortunately as the Diversion channel was eroding and enlarging the Lower Wairau River was aggrading and reducing in capacity due to its inability to pass its sediment load with reduced flood flows. It is estimated that approximately $2,000,000m^3$ of sediment was deposited on the bed of the Lower Wairau River in the time between the Diversion's introduction in 1964 and 2010, raising the Lower Wairau's bed upwards of 1.5m in some locations. A numerical morphological model (MIKE-11 ST) was used to assess a number of options which led to the decision and resource consent to construct an erodible (fuse plug) bank at the head of the Wairau Diversion to divert more frequent scouring-flows ($+400m^3/s$)down the Lower Wairau River. Full control gates were ruled out on the grounds of expense. The initial construction of the erodible bank followed in late 2009 with the bank's level at the fuse location set to overtop and begin washing out at a combined Wairau flow of $1,400m^3/s$ which avoids berm flooding in the Lower Wairau. In the three years since the erodible bank was first constructed the Wairau River has sustained 14 events with recorded flows at Tuamarina above $1,000m^3/s$ and three of events in excess of $2,500m^3/s$. These freshes and floods have resulted in washout and rebuild of the erodible bank eight times with a combined rebuild expenditure of $80,000. Marlborough District Council's Rivers & Drainage Department maintains a regular monitoring program for the bed of the Lower Wairau River, which consists of recurrently surveying a series of standard cross sections and estimating the mean bed level (MBL) at each section as well as an overall MBL change over time. A survey was carried out just prior to the installation of the erodible bank and another survey was carried out earlier this year. The results from this latest survey show for the first time since construction of the Wairau Diversion the Lower Wairau River is enlarging. It is estimated that the entire bed of the Lower Wairau has eroded down by an overall average of 60 mm since the introduction of the erodible bank which equates to a total volume of $260,000m^3$. At a cost of $$0.30/m^3$ this represents excellent value compared to mechanical dredging which would likely be in excess of $$10/m^3$. This confirms that the idea of using the river to enlarge the channel is again working for the Wairau River system and that in time nature's "excavator" will provide a channel capacity that will continue to meet design requirements.

• Journal of Wetlands Research
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• v.23 no.4
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• pp.317-326
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• 2021

The present study was carried out with a view to understand the distribution and ecology of Clihton retropictus (Martens, 1879), a class II endangered wildlife designated and protected by the Ministry of Environment, Republic of Korea, and to suggest the effective conservation and management measures for this species and its habit. First, the distribution of Clihton retropictus was investigated nationwide, and environmental factors such as salinity and substratum were analyzed in consideration of the ecological characteristics of this species. In addition, the individual size, density, and movement of Clihton retropictus per each district surveyed were analyzed. Due to its nature of inhabiting in the brackish water zone, the analysis showed that the salinity of this species was 0.7 ~ 16.6‰ at low tide and 1.0 ~ 17.3% at high tide. It was learned from the analysis of substratum that its composition in each river under investigation was slightly different, but most of substratum had a higher composition ratio than gravel (pebble, 16 ~ 64 mm). On the other hand, the size of each individual was checked by measuring the length of its diameter, and there was almost no change in the individual when the inhabited range of Clihton retropictus was short. However, there was tendency that the longer the habitat range, the bigger the individual size. From surveying the population density by season, it was made clear that, during the summer (July to August) and fall (September to October), the density was relatively higher while the number of individuals decreased significantly during winter (November to December) when the water temperature was lowered. In an effort to effectively establish conservation and management measures, the moving distance was measured, and it became known that, during the surveys in summer and fall when the individuals were active, the individuals moved in more distances than during the winter survey. The results of this study are expected to be utilized as basic data for establishing effective management plans such as creation of habitats for Clihton retropictus, its migration projects and selection of migration destinations which get unavoidable due to development projects.

• Knowledge Management Research
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• v.22 no.3
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• pp.217-233
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• 2021

Small business owners are currently greatly affected by the economic downturn caused by COVID-19. It is a study on the expected effect of education on management education of small business owners and the sustainability of the project on the premise that education can increase the self-sustainability of small business owners amid the rapidly changing global economy and consumer sentiment due to COVID-19. The following research results were derived by surveying those who completed management education of the Small Business Market Promotion Foundation. Management education was found to have a positive effect on education expectation effect, and education expectation effect was also found to have a positive effect on sustainability. In addition, management education had a positive effect on the sustainability of the project, and the expected effect of education was mediated between management education and sustainability. These results show that management education has a positive effect on survival and continuous performance in the business of small business owners, and steady efforts to acquire education can be said to be helpful in management activities. As a practical implication, first, since positive education expectations for management education can be seen as affecting the sustainability of the project, it should be possible to increase the expected effect by configuring interest and interest in education when forming management education programs. Second, management education directly affects the maintenance, survival, and sustainability of small business owners, and the knowledge acquired by participating in education helps improve management activities, so you can think of adding the amount and number of educational support. Third, since the sustainability of small business owners also affects the survival of the business, more active promotion of education will be needed so that more small business owners can receive management education.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.344-351
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• 2019

The purpose of this study was to obtain the basic data for developing more advanced courses on character education by surveying and analyzing the perception and demands of character education of university students and further, to provide useful information for creating institutional protocol on character education. The study was conducted from April 2018 to May 2018 on students attending the departments of non-health science and health science university students. A total of 206 students participated in this study, and all the students in the non-health science and health science departments were found to be highly aware of the need for character education, its importance and the possibility of personality development through learning. Students from all the departments showed high levels on average in terms of self-understanding according to their personality abilities, and especially their high levels of 'consideration' and 'responsibility'. For the differences in perception of self-efficacy, the lowest level of recognition was for 'will' and the average values were not high. In their response to personality level, all students answered that their personality was 'high' (42.1%), and that the personality education courses at the schools they are currently attending were 'not satisfied' with both the non-health science and health science students. As a result, there were higher results overall for the health science students than that for the non-health science students, but there were not many significant differences. To this end, education institutes will have to prepare conditions for university students to cultivate their expertise in character, while at the same time helping them grow into human beings with the qualities demanded by society. In addition, the government should establish curriculums and content by accurately identifying the needs of character education and devising concrete measures for their implementation, and by more faithfully considering quantitative and qualitative context types for the content base of character education.

• Journal of The Korean Society of Grassland and Forage Science
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• v.39 no.2
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• pp.89-96
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• 2019

This study was conducted to investigate 106 grassland farms in six provinces including Chungcheongbuk-do, Gangwon-do, Gyeonggi-do, Gyeongsangbuk-do, Gyeongsangnam-do, Jeju-do, and Jeollanam-do to present their problems and causes by surveying the actual state of grassland farms during three years(2014~2016). The grassland survey was divided into three categories; used as the perennial grasses and annual forage crops (Complied with Grassland Act), not used as the perennial grasses and annual forage crops (Not complied with Grassland Act) and failed to meet the farmer and some items are missing or inaccurate (Insufficient contents). Among the surveyed grassland farm, 68 farms (64.2 %) were complied with Grassland Act but 30 farms (28.3 %) were not complied with Grassland Act. Especially, the 8 farms (26.7 %) not complied with Grassland Act used the grassland as other purposes such as tree growing, golf club and swine farm etc.. Therefore, strict on-site investigation by local governments is required to prevent the grassland from being used by illegal purposes. And there's a strong likelihood that 5 farms (62.5 %) avoided the survey violate the positive law. Grassland grades used by the local administrative agencies were not influenced by the factors affecting the yield (existence and non-existence of overseeding and fertilization by grassland grade, soil pH and organic matter content). This results suggest that there is a fundamental problem on the current grassland grade system based on the yield and the irregular time of investigation and lack of on-site investigation are another causes for inaccurate grassland grade. Therefore, the new method evaluating grassland grades which is not based on yield and the thorough on-site investigation by local administrative agencies are necessary when the grassland grade is evaluated.

• Journal of the Korean Society of Radiology
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• v.13 no.2
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• pp.193-200
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• 2019

The study was conducted surveying ultrasound room workers on hospital infection awareness in Daejeon and Choong-chunng region. The contamination of ultrasonic probes used in clinical trials was measured using ATP, and the results were verified after using 70% alcohol sterilization. It was measured on the group's general characteristics and the specific categories such as academic background, job type, having professional certificate and infection education. After the examination, the gel removal and method, disinfection status of the probe and variable correlation analysis were performed to analyze the recognition of the ultrasonic probe disinfection. After examination in ultrasound room, it was found that towels were used the most for cleaning, and the gel container was not replaced for more than three months. After 70% alcohol disinfection, ATP contamination was reduced from $1055.4{\pm}944.2$ to $133.5{\pm}93.2$ and the result was analyzed to be statistically significant.(${\rho}<0.01$) The found bacteria were CNS, Gram positive bacillus, and Micrococcus specs. In order to solve this problem, 70% alcohol sterilization was applied and the bacteria were not detected after the treatment. The research shows that regular training on infection control and efforts to prevent infection are necessary, and that 70% alcohol is effective in disinfect the bacteria. Therefore, the medical institution should provide active hospital infection control education to improve the awareness of hospital infection among workers and contribute to the prevention of patient infection. It is also understood that proper use of the results of this study will help prevent infection by means of ultrasonic probes.

• Korean Journal of Environment and Ecology
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• v.33 no.5
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• pp.578-586
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• 2019

The purpose of this study was to investigate the change of spatial distribution of Korean red pine (Pinus densiflora Siebold & Zucc.) in Hallasan National Park by surveying the distribution and crown density and analyzing by the elevation, slope, orientation, and regional habitat in 2006 and 2015. The total area of the Korean red pine forest was 1,259.9 ha in 2015, which increased by 51.4 ha, or 4.1%, compared to 1,208.5 ha in 2006. For the past 10 years, the area of sparse density with crown density of 11% to 40% of Korean red pine increased by 59.8 ha, the area of moderate density with crown density of 41% to 70% increased by 59.0 ha, and the area of dense density with 71% or more crown density increased by 67.3 ha. In terms of the altitude above sea level, the Korean red pine forest area between 1,010 m and 1,400 m was the largest at 1,003.0 ha or 79.6% of the total area in 2015. The area between 1,100 m and 1,300 m increased, and the area of dense density decreased significantly while the areas of moderate density and sparse density increase. There was no notable change according to the land slope, and the area increased from 2006 regardless of the slope. By direction, 56.4% were distributed in the southwest and southeast directions centered on the south-facing slope with the increase of 27.8 ha over the 10 years while the northwest and northeast directions centered on the north-facing slope decreased by 7.6 ha. Regarding the distribution change of the Korean red pine forest by the region, the Yeongsil area showed an increase of 25.5 ha, or 49.6% of the total area increase, in 2006 while the Ibseog-oreum area including the right side on the Sanbeoleum mountain valley increased by 20.4 ha. The distribution in the Gaemideung area that includes Jogeundeule increased by 7.4 ha while that of Sogbat in Sungpanak Trail decreased by 1.9 ha. This study analyzed the changes in the distribution area and crown density of the Korean red pine forest according to the altitude, slope, direction, and regional habitat in Hallasan National Park. The expansion of Korean red pine forest distribution was limited to the areas where the grass and the shrub was the dominating vegetation structure, or the forest gap was created by the disturbance. On the other hand, the distribution area of the Korean red pine forest surrounded by deciduous broad-leaved forests or mixed vegetation structure is considered to result from the change in density more than the area due to competition with deciduous broad-leaved trees.

• Journal of Environmental Impact Assessment
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• v.29 no.6
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• pp.414-429
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• 2020

For the management of rivers, the target water quality is set by establishing the total amount of water pollution and water environment basic plan. For Geumho river T-P has achieved the target water quality, but for BOD, COD, TOC the target water quality of the water environment basic plan has been exceed for the past five years. Therefore, the flow rate for satisfying the target water quality was simulated by analyzing the load, load density, and pollution contribution rate of the Geumho river using BOD, COD, TOC and by utilizing QUAL-MEV a one-dimensional water quality model. According to the analysis of the load, the BOD, COD and TOC all showed the highest levels at the Geumho C point at 9,832.2 kg/day 20,656.6 kg/day, and 15,545.1 kg/day. The load density was highest at 9.47 kg/day/㎢, 37.55 kg/day/㎢, 30.20 kg/day/㎢, and 17.19 kg/day/㎢, 39.14 kg/day/㎢ in Dalseocheon stream during the wet seasons and dry seasons. Pollution contribution rate was highest at about 25 percent for Palgeocheon stream during the wet season and about 50 percent for Dalseocheon stream during the dry season. In addition, the correlation analysis between organic materials showed in the main stream and tributaty of the Geumho river that COD-TOC was 0.8 or higherthan BOD-COD and BOD-TOC in both the wet seasons and dry seasons. And after surveying the total amount of water pollution and the target quality of the water environment basic plan at Geumho C, it was analyzed that an additional flow tate of 14 times and 22 times was needed as of April 2019 (3.46 ㎥/sec).

• Korean Journal of Remote Sensing
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• v.36 no.6_1
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• pp.1449-1463
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• 2020

As recent global warming and climate changes become more serious, the importance of CO2 absorption by forests is increasing to cope with the greenhouse gas issues. According to the UN Framework Convention on Climate Change, it is required to calculate national CO2 absorptions at the local level in a more scientific and rigorous manner. This paper presents the gridded expansion of forest flux observations and mapping of daily CO2 absorption by the forests in Korea using numerical weather prediction data and satellite images. To consider the sensitive daily changes of plant photosynthesis, we built a machine learning model to retrieve the daily RACA (reference amount of CO2 absorption) by referring to the climax forest in Gwangneung and adopted the NIFoS (National Institute of Forest Science) lookup table for the CO2 absorption by forest type and age to produce the daily AACA (actual amount of CO2 absorption) raster data with the spatial variation of the forests in Korea. In the experiment for the 1,095 days between Jan 1, 2013 and Dec 31, 2015, our RACA retrieval model showed high accuracy with a correlation coefficient of 0.948. To achieve the tier 3 daily statistics for AACA, long-term and detailed forest surveying should be combined with the model in the future.