• The Korean Journal of Ecology
• /
• v.1 no.2
• /
• pp.57-65
• /
• 1977

The biomass and net production of alder and oak trees was estimated by allometric method. The productivity of the two stands of alder and oak was obviously different judging from the rate of photosynthesis productive structure and vertical distribution of light. The amounts of net photosynthesis under the saturated light were 2.31, 1.42mg $CO_2/dm^2\cdot$hr. in the sun and shade leaves of alder tree and 1.58, 0.84mg $CO_2/dm^2\cdot$hr in that of the oak, respectively. Total annual respiration loss calculated from the respiration measured at $25^{\circ}C$ and the mean air temperature from every 10 days were 13.56ton/ha.yr in the alder stand and 19.83 ton/ha.yr in the oak. The productive structure and the vertical distribution of light in the stand were assumedly more effective to produce dry matter in the oak stand than in the alder. The biiomasses measured in 1975 and 1976 were 51.51 and 56.82 ton/ha in the alder stand and 73.35, 86.77 ton/ha in the oak one, respectively. Annual net production and gross production were 8.56 and 22.12 ton/ha.yr in the alder stand but those were 17.90 and 37.74 ton/ha.yr in the oak stand. The ratios of respiration to gross procution (R/Pg) were prespectively 0.61 and 0.53 inthe alder and oak stands. Efficiencies of solar energy utilizaztion of net production during the growing season(May-Oct.) were 0.67 and 1.40% and those of gross production were 1.72 and 2.94% in the alder and oak stands respectively.

• Fisheries and Aquatic Sciences
• /
• v.12 no.2
• /
• pp.118-129
• /
• 2009

To develop a sustainable management model for oyster farming in Pukman Bay, Korea, we estimated the carrying capacity for oyster farming using food availability data. Optimal culture densities were calculated to be 124-133 individuals per unit flux area ($m^2$) and 310-330 individuals per string. The present annual production is approximately 1,038 tons/year, which is 87% of the estimated maximum yield of 1,193 tons/year. Therefore, considering annual fluctuations and a critical buffer to reduce ecological impacts, the current level is within optimal conditions. During periods of increased water temperature, energy demand was largely met by high primary production. The food supply significantly decreased as the harvest season approached, and 10 out of 21 oyster farms had a deficient food supply for at least 1 month. Therefore, these farms (39% of the farms within the bay) exceeded optimal densities.

• Asian Journal of Turfgrass Science
• /
• v.11 no.4
• /
• pp.281-288
• /
• 1997

This study was performed to find out the mineral cycles of sulphur in dynamic grassland ecosystems in a steady state condition at the northwest side on Mt. Kwanak. The experimental results may be summarized on the communities of a Zoysia japonica and a Miscanthus sinensis as follows. As compared with some properties of the surface soils among two semi-natural grasslands, sulphur war greater quantity in a Miscanthus sinensis than in a Zoysia japonica on Mt. Kwanak . For the case of steady production and release, the raion of annual mineral production to the amount accumulated on the top of mineral soil in a steady state provides the estimates of release constant k. The release constants on sulphur of the litter were 0.54 in a Zoysia japonica and 0.36 in a Miscanthus sinensis grassland. The half times of S required for the release or accumulation of the litter on the grassland were 1.28 years in a Zoysia japonica and 1.93 years in a Miscauthus sinensis The amounts of annual cycles for sulphur in the grassland ecosystem under the steady-state conditions were 20.65g /$m^2$ in a Zoysia japonica and 26.28g /$m^2$ in a Miacanthus sinensis grassland. Key words: Zoysia japonica Miscanthus sinensis Mt. Kwanak, Sulphur, Mineral cycles.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.59 no.9
• /
• pp.1566-1574
• /
• 2010

This paper presents an in-depth review for current status for demand-side management (DSM) investment of energy supplier and an useful prospect on the introduction of Energy Efficiency Resource Standards (EERS). According to the Article 9 of Rational Energy Utilization Act, Energy suppliers-Korea Electric Power Corporation (KEPCO), Korea Gas Corporation (KOGAS) and Korea District Heat Corporation (KDHC) prescribed by Presidential Decree-must establish and implement annual demand-side management investment plan to improve energy efficiency in production, transformation, transportation, storage and usage of corresponding energy and to reduce demand and green house gas emissions. In this paper, we examine the DSM programs of energy suppliers and the results of DSM investment in 2009, then we propose a reasonable solution for the development of DSM investment. Furthermore, in order to compare our situation, the case studies were conducted on EERS issues in England, Italy, France and U.S, such as establishing the energy saving target, selecting the target energy supplier, and penalty and incentive mechanisms. Throughout the case studies, this paper suggests the directions to the DSM investment planning of energy suppliers and the major issues to prepare EERS in Korea.

• Journal of the Korean Society of Industry Convergence
• /
• v.27 no.1
• /
• pp.173-182
• /
• 2024

While the current share of marine energy in South Korea is less than 1%, it is globally recognized as a resource approximately four times the annual electricity production. Considering the diverse geographical features of the East Sea, South Sea, and West Sea, marine energy development is crucial for South Korea and essential for achieving the 2050 carbon neutrality goal. Policy efforts for marine energy deployment focus on establishing an innovative, open, and integrated R&D system to respond flexibly. The construction of a scientific, economic, and social valid site selection system, along with a maritime spatial planning regime that considers environmental and socio-economic impacts, is emphasized. To expedite the early activation of marine energy, comprehensive policy endeavors, including discriminatory support policies and participation in international standardization, are anticipated to contribute to the sustainable development and dissemination of marine energy. Marine renewable energy plays a significant role in sustainability and addressing climate change, considered an essential component of South Korea's efforts toward carbon neutrality.

• International Journal of Advanced Culture Technology
• /
• v.4 no.1
• /
• pp.1-9
• /
• 2016

The demand for energy in Thailand has been continually increasing as the economic and social country grows. Approximately 60% of Thailand's primary energy is imported, mostly petroleum products. In 2008 Thailand's total energy consumption was 80,971 ktoe and the net price of energy imported was up to 1,161 billion Baht which is equivalent to 12.8% of GDP at the current price. The energy consumption or energy demand has been growing at an annual compounded growth rate of 6.42% and the peak electric power demand and electricity consumption was recorded at 22,568 MW and 148,264 GWh and grew at a rate of 7.0% and 7.5% per annum during the period from 1989 to 2008. The gross agriculture production in 2008 was recorded at 135.4 Mt which represents agriculture residue for energy at 65.73 Mt, which is equivalent to energy potential of about 561.64 PJ or 13,292 ktoe an increase in average of 5.59% and 5.44% per year respectively. The agricultural residues can converted to 15,600 GWh/year or 1,780 MW of power capacity. So, if government sector plan to install small biomass gasification for electricity generation 200 kW for Community. The residue agricultural is available for 8,900 plants nationwide. The small biomass power generation for electricity generation not only to reduce the energy imports, it also makes the job and income for people in rural areas as well. This paper's aim is to report the energy situation in Thailand and has studied 5 main agricultural products with high residue energy potential namely sugarcane, paddy, oil palm, cassava, and maize appropriate for small electricity production. These agricultural products can be found planted in many rural areas throughout Thailand. Finally, discuss the situation, methods and policies which the government uses to promote small private power producers supplying electricity into the grid.

• New & Renewable Energy
• /
• v.19 no.4
• /
• pp.98-107
• /
• 2023

A study was conducted to analyze data from 1981 to 2020 for understanding the impact of climate on solar energy generation. A significant increase of 104.6 kWhm^-2 was observed in the annual cumulative solar radiation over this period. Notably, the distribution of solar radiation shifted, with the solar radiation in Busan rising from the seventh place in 1981 to the second place in 2020 in South Korea. This study also examined the correlation between long-term temperature trends and solar radiation. Areas with the highest solar radiation in 2020, such as Busan, Gwangju, Daegu, and Jinju, exhibited strong positive correlations, suggesting that increased solar radiation contributed to higher temperatures. Conversely, regions like Seosan and Mokpo showed lower temperature increases due to factors such as reduced cloud cover. To evaluate the impact on solar energy production, simulations were conducted using climate data from both years. The results revealed that relying solely on historical data for solar energy predictions could lead to overestimations in some areas, including Seosan or Jinju, and underestimations in others such as Busan. Hence, considering long-term climate variability is vital for accurate solar energy forecasting and ensuring the economic feasibility of solar projects.

• 한국신재생에너지학회:학술대회논문집
• /
• 2009.06a
• /
• pp.668-671
• /
• 2009

This study seeks to develop a map of the domestic small hydropower(SHP) resources to further improve SHP resources, developed through package tool which can accurately evaluate a wide range of SHP basin in a short period of time. GIS-based package tool for SHP resources analysis was calculated using 840 standard basin classified by drainage area and facility capacity, etc., and to assume a 40% annual load factor, expected annual electricity production was calculated. SHP resources potential for the development of SHP will be utilized as basic data.

• 한국태양에너지학회:학술대회논문집
• /
• 2009.04a
• /
• pp.139-144
• /
• 2009

The generation of small hydropower as compared to other different developed environmental methods produces one of the clean energies. In such manner, various application system development through IT technique is being developed for an advanced small hydropower energy resources data mining. However, existing data analysis of New & Renewable Information System for small hydropower resources application is incomplete therefore it limits expressing these information on the Web. Thus for positive usage of small hydropower resources, a more systematic and precise analysis system should be built. This study seeks to develop a map of the domestic small hydropower resources problems to further improve small hydropower resources, developed through Package Tool which can accurately evaluate a wide range of small hydropower basin in a short period of time. Small hydropower Package Tool was calculated using existing Analysis System small hydropower resources which did not provide diverse capabilities resulting to 840 standard basin classified by A and facility capacity, etc., and to assume a 40% annual capacity, expected annual electricity production was calculated. Small hydropower for the national water system of small hydropower resources potential calculated in terms of resources for the development of small hydropower will be utilized as basic data.

• Journal of the Korean Institute of Educational Facilities
• /
• v.11 no.5
• /
• pp.14-23
• /
• 2004

Building-integrated photovoltaic(BIPV) systems can operate as a multi-functional building components, which generates electricity and serves as part of building envelope. It can be regarded as a new architectural elements, adding to the building's aesthetics. Besides of these benefits, the application of PV systems into school buildings tends to play an important role in energy education to students. In this context, this study aims to analyse the applicability of PV systems into school buildings. For an existing school building, four types of BIPV designs were developed; rooftops, wall-attached, wall-mounted with angle, and sunshading device. Based on energy modeling of those BIPV systems, the whole 60.1kWp rated PV installation is expected to yield about 65.6MWh of electricity, that is about 50% more than the annual electricity consumption of the school, 44MWh. It was also found that the applicability of the PV systems into the school building was very high, and the rooftop systems with the optimized angle was the most efficient in energy production, followed by sunshading, wall-mounted with angle and wall-attached. It concludes that school buildings have a reasonable potential to apply PV systems in the aspects of building elements and electricity production.