• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.2
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• pp.205-210
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• 2012

For environmental reasons and because of our limited energy resources, high-efficiency power generation technology will be necessary in the future. Ultra-supercritical (USC) power generation technology is the key to managing the greenhouse gas problems and energy resource problems discussed in the Kyoto Protocol to the United Nations Framework Convention on Climate Change. Other countries and manufacturers are trying to build commercial power plants. In this paper, an efficient method of achieving near-zero emission operation of a high-efficiency fossil power plant using USC power generation is discussed. Development of USC power generation in Korea has been supported by the Korean government in two phases: Phase I was USC key technology development from 2002 to 2008, and Phase II is USC development and technology optimization from 2010 to 2017.

• Journal of Forest and Environmental Science
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• v.15 no.1
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• pp.71-76
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• 1999

This study compared soil characteristics and carbon storage between urban and natural lands in Chunchon. Soil pH was lower in natural lands (5.0) than in urban lands (6.6), and therefore exchangeable cation was a little lower in natural lands. Organic matter and cation exchange capacity were respectively, 1.4 and 1.7 times higher in natural lands than in urban lands, while available $P_2O_5$ was about 3.2 times higher in urban lands. Organic carbon storage in soils averaged $24.8{\pm}1.6$ (standard error) t/ha in urban lands and $31.6{\pm}1.6t/ha$ in natural lands, 1.3 times greater than in urban lands. Annual carbon accumulation in soils of natural lands was 1.3 t/ha/yr (litterfall minus decomposition). The carbon storage in Chunchon' s soils equaled about 31% of annual carbon emission (245,590 t/yr).

• Journal of the Korean Solar Energy Society
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• v.32 no.3
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• pp.138-145
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• 2012

Because of the climate changes and the development of building technologies, the cooling loads have been increased. Among the various renewable energies, geothermal energy is known as very useful and stable energy for heating and cooling of building. This study proposes a road snow-melting system of which heat is supplied from GSHP(Ground source heat pump) in viewpoint of the initial investment and annual running performance, which is also operating as a main facility of heating and cooling for common spaces. The results of this study is as followings. From the site measurement, it is found out that the road surface temperature above the geothermal heating pipe rose up to $5^{\circ}C$, which is the design temperature of road snow-melting, after 2 hours' operation and average COP(Coefficient of performance) was estimated as 3.5. The reliability of CFD has confirmed, because the temperature difference between results of CFD analysis and site measurement is only ${\pm}0.4^{\circ}C$ and the trend of temperature variation is quite similar. CFD analysis on the effect of pavement materials clearly show that more than 2 hours is needed for snow-melting, if the road is paved by ascon or concrete. But the road paved by brick is not reached to $5^{\circ}C$ at all. To evaluate the feasibility of snow-melting system operated by a geothermal circulation which has not GSHP, the surface temperature of concrete-paved road rise up to $0^{\circ}C$ after 2 hour and 40 minutes, and it does never increase to $5^{\circ}C$. And the roads paved by ascon and brick is maintained as below $0^{\circ}C$ after 12 hours geothermal circulation.

• Journal of the Korea Society of Computer and Information
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• v.15 no.11
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• pp.233-239
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• 2010

The research which sees the fact that about model found of the duty factor whom follows in old person welfare facility worker holding office duration and organized performance researches in purpose. From theoretical background about the old person welfare facility system investigated a theory about the duty factor and organized performance of literature investigation and the old person welfare facility worker. A theory analysis of positive data led based on about the effect factor of the causality which the duty factor of the old person welfare facility worker reaches in organized performance under verifying boil the modulating effect of holding office duration. The repair which is a duty factor of the old person welfare facility worker, according to the holding office duration which is a personal quality factor job satisfaction the promotion and organized natural features, business environment and organized structure are organized performance and organization immersion and loyalty degree different assumed with the fact that will affect. From positive analysis about the research object verifies a suitable degree about demographics school register analytical and study model, structural equation model leads and construction verification and modulating effect analysis under executing boil.

• Korean Journal of Environment and Ecology
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• v.28 no.2
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• pp.171-181
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• 2014

This study was performed to prevent deforestation and forest degradation and vitalize REDD+ program through suitable site analysis at the 16 districts of South Korea. For this, we worked out profit potential, opportunity cost, carbon credits through making it use of conception of the Forest Carbon Index. As a results, Gyeonggi-do, Incheon Metropolitan City, Seoul Metropolitan Government, Daegu Metropolitan City, Gwangwon-do included in the top 5 among the 16 districts of South Korea. In case of Gyeonggi-do as best suitable site, reduction of carbon emission was best high due to reduction area of deforestation. And profit potential was also high in accordance with practice of REDD+ program. Furthermore, we proposed four plans to activate REDD+ program in South Korea on the basis of the results.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.629-632
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• 2009

The polymeric desiccant rotor is made from the super absorbent polymer by ion modification. The moisture sorption capacity of the super desiccant polymer(SDP) is 4 to 5 times larger than those of common desiccant meterials such as silica gel or zeolite. It is also known that SDP can be regenerated even at the relatively low temperature. To fabricate the desiccant rotor, firstly the SDP was laminated by coating the SDP on polyethylene sheet. Then corrugated and rolled up into a rotor. The diameter, the depth, the dimensions of the corrugated channel, etc. were pre-determined from numerical simulation on the heat and mass transfer in the desiccant rotor. The dehumidification performance was tested in a climate chamber. The relevant tests were carried out at the process air inlet temperature of $32^{\circ}C$, the regeneration air inlet temperature of $60^{\circ}C$ and the inlet dew-point temperature of both the process air and the regeneration air of $18.5^{\circ}C$, when the rotation period is long, the moisture sorption is not effective. In the desiccant rotor developed in this study, the optimum rotation period is found about 350s at the regeneration temperature of $60^{\circ}C$. It was found from further experiments that the optimum rotation tends to decreases as the regeneration temperature increases. Meanwhile, the outlet temperature of the process air deceases monotonically as the rotation period increases.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.2
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• pp.19-27
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• 2016

Maritime transport is now regarded as one of the main contributors to global climate change by virtue of its $CO_2$ emissions. Meanwhile, slow steaming, i.e., slower ship speed, has become a common practice in the maritime industry so as to lower $CO_2$ emissions and reduce bunker fuel consumption. The practice raised various operational decision issues in terms of shipping companies: how much ship speed is, how much to bunker the fuel, and at which port to bunker. In this context, this study addresses an operation problem in a shipping companies, which is the problem of determining the ship speed, bunkering ports, and bunkering amount at the ports over a given ship route to minimize the bunker fuel and ship time costs as well as the carbon tax which is a regulatory measure aiming at reducing $CO_2$ emissions. The ship time cost is included in the problem because slow steaming increases transit times, which implies increased in-transit inventory costs in terms of shippers. We formulate the problem as a nonlinear lot-sizing model and suggest a Lagrangian heuristic to solve the problem. The performance of the heuristic algorithm is evaluated using the data obtained from reliable sources. Although the problem is an operational problem, the heuristic algorithm is used to address various strategic issues facing shipping companies, including the effects of bunker prices, carbon taxes, and ship time costs on the ship speed, bunkering amount and number of bunkering ports. For this, we conduct sensitivity analyses of these factors and finally discuss study findings.

• Ecology and Resilient Infrastructure
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• v.5 no.3
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• pp.145-155
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• 2018

In a monsoonal climate, the soil seed bank can play an important role in plant regeneration after the severe annual floods that disturb above-ground vegetation within the riparian zone. To investigate the relationship between the soil seed bank and vegetation, we measured the species composition of the soil seed bank and the extant above-ground vegetation in six major plant communities (Artemisia selengensis, Miscanthus sacchariflorus, Persicaria nodosa, Phalaris arundinacea, Phragmites japonica, and Rorippa palustris) in the Cheongmicheon Stream, Korea. A total of 21 species germinated from the floodplain soil seed banks. The most diverse seed bank (21 species) was found in the A. selengensis community, wheres the lowest number of species was found in the R. palustris community (2 species). Most soil seed banks were composed of annuals (90%), exceptions being Rumex crispus and Artemisia princeps, which are perennial ruderals. The similarity of species composition between the soil seed bank and above-ground vegetation was low with Sorensen's similarity indices averaging 29% (range 12 - 42%). Crucially, existing dominant perennials of the extant vegetation including A. selengensis, M. sacchariflorus, P. japonica and P. arundinacea were absent from the soil seed bank. In conclusion, the soil seed banks of the floodplains of the Cheongmicheon Stream were mainly composed of viable seeds of ruderal plants, which could germinate rapidly after severe flood disturbance. The soil seed bank may, therefore, be useful for the restoration of the early succession stages of riparian vegetation after flood disturbances.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.18 no.2
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• pp.19-32
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• 2015

In Korea, significant riparian areas have been developed due to river maintenance projects. Introduction of new riparian facilities can negatively affect wildlife in the riparian areas. This study focuses on selecting core conservation areas for Eurasian Otter(Lutra lutra) to support decision making process for development of riparian areas. For the study, first of all, field data of study site were collected by field surveys. Secondly, stream naturalness was assessed to understand physical environments of the study sites. Thirdly, habitat suitability was assessed using occurrence data of Eurasian Otter and environmental data. Lastly, core areas for conservation was selected by comparing and synthesizing stream naturalness map and habitat suitability map. The selected core areas showed several characteristics. The number of artificial facilities is low in the core areas. Rocks which are preferred by Eurasian Otter to eat and excrete are plentiful in the core areas. Also, the ratio of adjacent farmland is high. Based on the analyses, it is expected that this study can contribute to decision making process for environmental spatial plans to better conserve habitats of Eurasian Otter.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.12 no.2
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• pp.61-72
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• 2009

This study aims to analyze the current situation of and issues in the structure of urban neighborhood parks and park facility installation in cities in Gyeonggi-do. Then, based on its findings, plans to improve the space structure of the parks were examined and suggested to raise the city environment improvement function and green area base function of urban parks and fully satisfy users' needs for pleasant rest, recreation and cultural activities. The findings showed that, within parks, the area of grass where access was restricted reached about 24.4% in average. In other words, only 75.6% of total park area could be freely used by park visitors. As for an improvement plan, the grass area where access is limited may be converted into a gras area that can be freely used to raise the park use area, which currently stands only at 75.6%, to 100%. The result of cross analysis through Chi-Square Test regarding lawn use as well as regarding (dis)agreement with reduction of lawn, based on the investigation of cognition, showed a significant agreement of park users with reduction of green areas. Therefore it is considered that lawn space must be reduced according the result of the analysis, to set up plans for facility space that would meet the desires of users. The analysis of user behaviors revealed that many of them used square spaces and walks; therefore it is considered that re-structuring of space is necessary according to local characteristics. This study also made some policy suggestion. urban parks must be a base of city green areas to counter climate changes. When developing a park creation plan, a user demand survey must be conducted in advance. In addition. grass construction methods should be improved to tolerate foot pressure.