• Korean Journal of Agricultural and Forest Meteorology
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• v.25 no.4
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• pp.436-445
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• 2023

Methane (CH₄) emissions from rice paddies are mainly observed using the closed chamber method or the eddy covariance method. In this study, a new observation technique combining a portable gas analyzer (Model LI-7810, LI-COR, Inc., USA) and an automatic opening/closing chamber (Model Smart Chamber, LI-COR, Inc., USA) was introduced based on the strengths and weaknesses of the existing measurement methods. A cylindrical collar was manufactured according to the maximum growth height of rice and used as an auxiliary measurement tool. All types of measured data can be monitored in real time, and CH₄ flux is also calculated simultaneously during the measurement. After the measurement is completed, all the related data can be checked using the software called 'SoilFluxPro'. The biggest advantage of the new observation technique is that time-series changes in greenhouse gas concentrations can be immediately confirmed in the field. It can also be applied to small areas with various treatment conditions, and it is simpler to use and requires less effort for installation and maintenance than the eddy covariance system. However, there are also disadvantages in that the observation system is still expensive, requires specialized knowledge to operate, and requires a lot of manpower to install multiple collars in various observation areas and travel around them to take measurements. It is expected that the new observation technique can make a significant contribution to understanding the CH₄ emission pathways from rice paddies and quantifying the emissions from those pathways.

• Journal of the Korean Institute of Landscape Architecture
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• v.51 no.5
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• pp.13-29
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• 2023

Urban parks are social infrastructure supporting citizens' health, quality of life, and community formation. As the proportion of urban parks that have been established for more than 20 years is increasing, the need for refurbishment to improve the physical space environment and enhance the functions of aging urban parks is increasing. Since the government's refurbishment of aging urban parks has limitations in securing financial resources and promoting attractiveness, they must be promoted through public-private partnerships. Japan, which suffered from the problem of aging urban parks, has successfully promoted several park refurbishment projects by introducing the Park-PFI through the revision of the 「Urban Park Act」 in 2017. This study examines and analyzes the characteristics of the Japan Park-PFI as an alternative to improving the quality of aging domestic urban park services through public-private partnerships and the validity of the aging urban park refurbishment projects through Park-PFI. The main findings are as follows. First, it is necessary to start discussions on introducing Japan's Park-PFI according to the domestic conditions as a means of public-private partnership to improve the service quality and diversify the functions of aging urban parks. In order to introduce Park-PFI social discussions and follow-up studies on the deterioration of urban parks. Must be conducted. The installation of private capital and profit facilities and improvements of related regulations, such as the 「Parks and Green Spaces Act」 and the 「Public Property Act」, is required. Second, it is judged that the Park-PFI project is a policy alternative that can enhance the benefits to citizens, local governments, and private operators under the premise that the need to refurbish aging urban parks is high and the location is suitable for promoting the project. As a result of a pilot application of the Park-PFI project to Seyeong Park, an aging urban park located in Bupyeong-gu, Incheon, it was analyzed to be profitable in terms of the profitability index (PI), net present value (FNPV), and internal rate of return (FIRR). It is considered possible to participate in the business sector. At the local government level, private capital is used to improve the physical space environment of aging urban parks, as well as the refurbishment of the urban parks by utilizing financial resources generated by returning a portion of the facility usage fees and profits (0.5% of annual sales) of private operators. It was found that management budgets could be secured.

• Korean Journal of Heritage: History & Science
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• v.56 no.3
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• pp.214-232
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• 2023

Stromatolite at the Daegu Catholic University, Gyeongsan was designated as a natural monument in December 2009 because it was very excellent in terms of rarity, accessibility, preservation and scale. From the time of designation, the necessity of confirming the lateral extension of the stromatolite beds with the excavation of the surrounding area, and preparing a preservation plan was raised. Accordingly, the Cultural Heritage Administration conducted an investigation of the scale, production pattern, and weathering state of stromatolites with an excavation from April to December 2022, and based on this, suggested natural heritage values and conservation and use plans. The excavation was carried out in a 1,186m² area surrounding the exposed hemispherical stromatolite (approximately 30m2). Stromatolites are continuously distributed over the entire excavation area, and hemispherical stromatolites predominate in the eastern region, and the distribution and size of hemispherical domes tend to decrease toward the west. These characteristics are interpreted as a result of long-term growth in large-scale lakes, where stratiform or small columnar domes continued to grow and connect with each other, finally forming large domes. Consequently, large and small domes were distributed on the bedding plane in clusters like coral reefs. The growth of plants and lichens, as well as small-scale faults and joints developed on the stromatolite bedding surface, is the main cause of accelerated weathering. However, preservation treatment with chemicals as with dinosaur footprints or dinosaur egg fossil sites is not suitable due to the characteristics of stromatolites, and preservation with the installation of closed protection facilities should be considered. This excavation confirmed that the distribution, size and value of stromatolites are much larger and higher than at the time of designation as a natural monument. Therefore, additional excavation of areas by experts that could not be excavated due to the discovery of buried cultural properties (stone chamber tombs) and reexamination of the expansion designation of natural monuments are required.

• Journal of Environmental Impact Assessment
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• v.32 no.6
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• pp.419-430
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• 2023

In response to the periodic occurrence of cyanobacterial blooms in Korean freshwaters, various types of cyanobacteria removal technologies are being developed and implemented. Due to the differing principles behind these technologies, it is difficult to compare and evaluate their removal efficiencies. In this study, a standardized method for evaluating cyanobacteria removal efficiency was proposed by utilizing the results of removal operations using a mobile cyanobacteria removal device in the Seohwacheon area of Daechung Reservoir. During removal operations, the decrease in chlorophyll-a (chl-a) concentration (ΔChl-a) in the working area was calculated based on the amount of collected sludge, the efficiency rate, and the concentration of chl-a. Additionally, the required working days (WD) to reduce the chl-a concentration to 1 mg/m³ in the target area was calculated based on the area of the target zone, the maximum daily working area, and the efficiency rate. A method for calculating the cyanobacteria removal capacity was proposed based on the reduction rate of chl-a concentration in the water before and after the operation, the treatment capacity of the removal technology, and the water volume of the target area. The cyanobacteria removal capacity of the mobile cyanobacteria removal device used in this study was 6.64%/day (targeting the Seohwacheon area of Daechung Reservoir, approximately 500,000 m²), which was higher compared to other physical or physicochemical cyanobacteria removal technologies (0.02~4.72%/day). Utilizing the evaluation method of cyanobacteria removal efficiency presented in this study, it will be possible to compare and evaluate the cyanobacteria removal technologies currently being applied in Korea. This method could also be used to assess the performance and efficiency of physical or physicochemical combined cyanobacteria removal techniques in the "Guidelines for the Installation and Operation of Algae Removal Facilities and the Use of Algae Removal Agents" operated by the National Institute of Environmental Research.

• Korean Journal of Ecology and Environment
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• v.56 no.3
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• pp.187-195
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• 2023

Almost all of the water from agricultural dams located to the upper of the Yeongsan river is supplied as irrigation water for farmland and thus is not discharged to the main stream of the river. Also, most of the irrigation water does not return to the river after use, adding to the lack of flow in the main stream. As a result, the water quality and aquatic health of the river have become the poorest among the four major rivers in Korea. Therefore, in this study, several strategies for water quality improvement of the river were developed considering pollution reduction and flow rate increase, and their effect analysis was performed using a water quality model. The results of this study showed that the target water quality of the Yeongsan river could be achieved if flow increase strategies (FISs) are intensively pursued in parallel with pollution reduction. The reason is because the water quality of the river has been steadily improved through pollution reduction but this method is now nearing the limit. In addition, rainfall-related FISs such as dam construction and water distribution adjustment may be less effective or lost if a megadrought continues due to climate change and then rainfall does not occur for a long time. Therefore, in the future, if the application conditions for the FISs are similar, the seawater desalination facility, which is independent of rainfall, should be considered as the priority installation target among the FISs. The reason is that seawater desalination facilities can replace the water supply function of dams, which are difficult to newly build in Korea, and can be useful as a climate change adaptation facility by preventing water-related disasters in the event of a long-term megadrought.

• Journal of Environmental Impact Assessment
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• v.33 no.1
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• pp.1-8
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• 2024

Amphibians are a taxonomic group that ecologically connects terrestrial ecosystems and aquatic ecosystems. They play a very important role in the food chain of the ecosystem. It is known that there are about 5,948 species distributed all over the world, but after the Industrial Revolution, due to industrialization and urbanization, there has been a decrease in species and populations. In particular, it is becoming a factor in exacerbating habitat fragmentation or fragmentation due to artificial canals. In orderto improve the survivalrate of wild animals in artificial canals, escape facilities are installed to reduce it. This study analyzed the slope, height of the escape facility, escape rate, and travel distance in the operating facility for Bombina orientalis, which mainly inhabits near forests. The slope of the escape facility showed a relatively similar escape success rate regardless of height at 50° and 60°, while at 70°, it showed a relatively high escape success rate at only 40cm in height. The success rate of escape from the waterway escape facility in operation was 14.71%, showing a very low utilization rate, and the recognition rate of the artificial canal escape facility was found to be very low as it moved along the side wall of the artificial canal. Therefore, in the case of a waterway escape facility for Bombina orientalis, it is possible to construct it at an angle of 60°, and if the side walls of the artificial canals are built within 60°, Bombina orientalis can move freely in both directions, overcoming the low utilization rate of existing waterway escape facilities. It is expected to minimize the impact of movement and death of artificial canals. In addition, if the spacing between escape facilities is narrowed from the installation standard of 30m and ramps are constructed in both directions upstream and downstream, the escape success rate of amphibians,reptiles, and small mammals otherthan lady frogs is expected to improve.

• Journal of The Korean Association For Science Education
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• v.44 no.2
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• pp.167-178
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• 2024

In this study, we investigated the perceptions of science-related careers and career education among middle school science teachers. Sixty-four science teachers experienced in teaching unit 7 in the first year of middle school participated. The results of the study revealed that not only careers in science but also careers with science were found to be quite high when teachers were asked to provide examples of science-related careers. Jobs related to research/engineering, which are careers in science, comprised the highest proportion of teachers' answers, followed by jobs related to education/law/social welfare/police/firefighting/military, and health/medical, which are careers with science. However, the proportion of jobs mentioned related to installation/maintenance/production was extremely low. The skills required for science-related careers were mainly perceived to consist of tools for working and ways of working. The number of skills classified under living in the world was perceived to be extremely low across most careers, irrespective of career type. Most teachers only taught unit 7 for two to four sessions and devoted little time to science-related career education, even in general science classes. In the free semester system, a significant number of teachers responded that they provide science-related career education for more than 8 hours. Teachers mainly utilize lecture, discussion/debate, and self-study activities. Meanwhile, in the free semester system, the resource-based learning method was utilized at a high proportion compared to other class situations. Teachers generally made much use of media materials, with the use of textbooks and teacher guides found to be lower than expected. There were also cases of using materials supported by science museums or the Ministry of Education. Teachers preferred to implementing student-centered classes and utilizing various teaching and learning methods. Based on the above research results, discussions were proposed to improve teachers' perceptions of science-related careers and career education.

• Journal of Chest Surgery
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• v.41 no.3
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• pp.329-334
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• 2008

Background: Percutaneous cardiopulmonary support. (PCPS) has the potential to rescue patients in cardiogenic shock who might otherwise die. PCPS has been a therapeutic option in a variety of the clinical settings such as for patients with myocardial Infarction, high-risk coronary intervention and postcardiotomy cardiogenic shock, and the PCPS device is easy to install. We report our early experience with PCPS as a life saving procedure in cardiogenic shock patients due to acute myocardial infarction. Material and Method: From January 2005 to December 2006, eight patients in cardiogenic shock with acute myocardial infarction underwent PCPS using the CAPIOX emergency bypass system($EBS^{(R)}$, Terumo, Tokyo, Japan). Uptake cannulae were inserted deep into the femoral vein up to the right atrium and return cannulae were inserted into the femoral artery with Seldinger techniques using 20 and 16-French cannulae, respectively. Simultaneously, autopriming was performed at the $EBS^{(R)}$ circuit. The $EBS^{(R)}$ flow rate was maintained between $2.5{\sim}3.0L/min/m^2$ and anticoagulation was performed using intravenous heparin with an ACT level above 200 seconds. Result: The mean age of patients was $61.1{\pm}14.2$ years (range, 39 to 77 years). Three patients were under control of the $EBS^{(R)}$ before percutaneous coronary intervention (PCI), three patients were under control of the $EBS^{(R)}$ during PCI, one patient was under control of the $EBS^{(R)}$ after PCI, and one patient was under control of the $EBS^{(R)}$ after coronary bypass surgery. The mean support time was $47.5{\pm}27.9$ hours (range, 8 to 76 hours). Five patients (62.5%) could be weaned from the $EBS^{(R)}$ after $53.6{\pm}27.2$ hours. (range, 12 to 68 hours) of support. All of the patients who could successfully be weaned from support were discharged from the hospital. There were three complications: one case of gastrointestinal bleeding and two cases of acute renal failure. Two of the three mortality cases were under cardiac arrest before $EBS^{(R)}$ support, and one patient had an intractable ventricular arrhythmia during the support. All of the discharged patients are still surviving at $16.8{\pm}3.1$ months (range, 12 to 20 months) of follow-up. Conclusion: The use of $EBS^{(R)}$ for cardiogenic shock caused by an acute myocardial infarction could rescue patients who might otherwise have died. Successfully recovered patients after $EBS^{(R)}$ treatment have survived without severe complications. More experience and additional clinical investigations are necessary to elucidate the proper installation timing and management protocol of the $EBS^{(R)}$ in the future.

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.2
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• pp.93-104
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• 2002

A field survey and experiment was conducted from 1996 to 1998 to develop rational technology for turfgrass vegetation of runway side of Incheon International Airport on the reclaimed tidal land in Young-Jong Island. Backfill of the experimental site was finished on August 1995. The experimental site was 8 ha located in the middle of the construction place for the main parking lot in front of the terminal building construction. The experimental field was drained by main open ditch, and divided three main plots, no subsurface tile drain, subsurface tile drain spacing with 22.5m, and with 45 m, respectively. The 17 sub plots were designed to test the effect of soil covering with red earth loam by 5 cm and 20 cm depth, application of chemical compound fertilizers and livestock manures, dressing of artifical soils and hydrophylic soil conditioners. The tested turfgrasses were three transplanting indigenous turfgrasses, Zoysia koreana, Zoysia sinica and Zoysia japonica, and two hydroseeding mixed exotic turgrasses, cool type I(tall fescue 30%, kentucky blue grass 40%, perenial ryegrass 30%), and cool type II(tall fescue 40%, perenial ryegrass 20%, fine fescue 20%, alkaligrass 20%). The soil backfilled with dredged seasand was sand textured with high salt concentration and low fertility. The soil showed high pH, low organic matter and low available phophate contents. The percolation rate was fast with high hydraulic conductivity. Desalinization was fast after installation of the main open drainage system. No subsurface tile drainage effect was found showing little difference in turfgrass growth. The covering and visual growth of turfgrasses were the best in the 20-cm soil covering with compound fertilizer treatment. The covering and visual growth of turfgrasses were satisfactory in the 5 cm soil covering with compound fertilizer treatment and with livestock manure treatments. The hydrophillic soil conditioner treatments were effective but expensive at present. The coverage and visual quality of turfgrasses were good for Zoysia koreana and Zoysia japonica. The coverages of turfgrasses by the hydroseeding with the mixed exotic turfgrasses were less than transplanting of native turfgrasses. In conclusion, for the runway side vegetation purposes, the subsurface tile drainage might not necessary as main open ditch drainage be sufficient due to fast percolation rate of the backfilled dredged seasand. The 5 cm soil covering with red earth might be sufficient for the runway side, but the 20 cm soil covering might be necessary for the runway side where high density of turfgrass coverage was necessary to protect from the airplance air blow.

• Journal of the Korean Institute of Landscape Architecture
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• v.48 no.5
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• pp.80-88
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• 2020

With the issuance of one-week fine dust emergency reduction measures in March 2019, the public's anxiety about fine dust is increasingly growing. In order to assess the application of air purifying plant-based bio-filters to public facilities, this study presented a method for measuring pollutant reduction effects by creating an indoor environment for continuous discharge of particle pollutants and conducted basic studies to verify whether indoor air quality has improved through the system. In this study conducted in a lecture room in spring, the background concentration was created by using mosquito repellent incense as a pollutant one hour before monitoring. Then, according to the schedule, the fine dust reduction capacity was monitored by irrigating for two hours and venting air for one hour. PM₁₀, PM_2.5, and temperature & humidity sensors were installed two meters front of the bio-filters, and velocity probes were installed at the center of the three air vents to conduct time-series monitoring. The average face velocity of three air vents set up in the bio-filter was 0.38±0.16 m/s. Total air-conditioning air volume was calculated at 776.89±320.16㎥/h by applying an air vent area of 0.29m×0.65m after deducing damper area. With the system in operation, average temperature and average relative humidity were maintained at 21.5-22.3℃, and 63.79-73.6%, respectively, which indicates that it satisfies temperature and humidity range of various conditions of preceding studies. When the effects of raising relatively humidity rapidly by operating system's air-conditioning function are used efficiently, it would be possible to reduce indoor fine dust and maintain appropriate relative humidity seasonally. Concentration of fine dust increased the same in all cycles before operating the bio-filter system. After operating the system, in cycle 1 blast section (C-1, β=-3.83, β=-2.45), particulate matters (PM₁₀) were lowered by up to 28.8% or 560.3㎍/㎥ and fine particulate matters (PM_2.5) were reduced by up to 28.0% or 350.0㎍/㎥. Then, the concentration of find dust (PM₁₀, PM_2.5) was reduced by up to 32.6% or 647.0㎍/㎥ and 32.4% or 401.3㎍/㎥ respectively through reduction in cycle 2 blast section (C-2, β=-5.50, β=-3.30) and up to 30.8% or 732.7㎍/㎥ and 31.0% or 459.3㎍/㎥ respectively through reduction in cycle 3 blast section (C-3, β=5.48, β=-3.51). By referring to standards and regulations related to the installation of vegetation bio-filters in public facilities, this study provided plans on how to set up objective performance evaluation environment. By doing so, it was possible to create monitoring infrastructure more objective than a regular lecture room environment and secure relatively reliable data.