• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2009.06a
• /
• pp.397-401
• /
• 2009

On the crisis of international economy, the government is making an effort to seek economic growing motivation with the method of overcoming economic crisis and 'low carbon green growth'. Furthermore, to promote maritime vessel traffic service related inefficient energy wastage was revealed and eco-friendly alternative energy was accepted because of high price of oil in the beginning of 2008. In this situation, I'm going to discuss the possibility of eco-friendly energy system in maritime vessel traffic service with the way of cutting the budget and expansion of solar power generation system which was promoted to meet governmental 'energy saving plan for high price of oil'.

• The Journal of the Convergence on Culture Technology
• /
• v.7 no.2
• /
• pp.359-366
• /
• 2021

It's been more than 30 years since global warming by the increase in CO2 became a cause celebre worldwide. Recently the government promulgated Framework Act on on Low-Carbon Green Growth and has been continuously putting much effort into saving energy and reducing carbon dioxide emissions such as an international climate change conference to prevent the increase in CO2. However, because most cities are not planned for energy saving, new cities should be planned as the active energy-efficient urban structure for 'sustainable urban development' from a long-term perspective. This study aims to design a new prototype for the sustainable energy-independent and environment-friendly housing estates which is the nation's new vision in the era of the Fourth Industrial Revolution. A study on the energy-independent site planning and the quantitative standardization of its factor will be conducted.

• Korean Journal of Environmental Agriculture
• /
• v.38 no.3
• /
• pp.124-132
• /
• 2019

BACKGROUND: Silver grass (Miscanthus sinensis) No. 1 was developed for production of bio-ethanol, and for the purpose the silver grass growing sector was established in Geumgang basin, Iksan, Jeonbuk, in 2011. However, the other application potentials except for using as the bio-energy resources should be considered because of the drop in international oil prices. Therefore, there is the necessity of a scientific basis to use the silver grass instead of rice straw as the organic matter source that is used for improvement of soil quality in the plastic film house. METHODS AND RESULTS: The silver grass was applied at 5, 10, 15 and 20 Mg/ha and tilled before the watermelon was planted in the plastic film-house. The control plot was treated with 10 Mg/ha with rice straw, and watermelons have been cultivated for 3 years(2017~2019). Soil aggregation, soil chemistry, and the growth characteristics were investigated, when the watermelon was harvested every year. Soil aggregation levels at the 2nd and 3rd year of watermelon harvest were similar from the plot applied with the silver grass at 5 Mg/ha and the control plot, and increased in the silver grass treated plots with more than 10 Mg/ha. However, there was no statistically significant difference between the plots. The nitrogen mineralization of silver grass in the control plot tended to be similar to the 5 Mg/ha plot, but the silver grass treated plots with over 10 Mg/ha showed low nitrogen mineralization. Soil EC on harvest stage was proportional to the applied mass of the silver grass, but pH was in inverse with the applied mass. Soil organic matter content, available phosphate, and exchangeable cations increased with the continued use of silver grass. Watermelon weight found to be the best on more than 15 Mg/ha of silver grass, and the sugar content was highest when 10 Mg/ha was treated. CONCLUSION: The use of the silver grass at 10 Mg/ha annually as the organic source was effective in replacing rice straw while growing fruits and vegetables on the plastic film house.

• Journal of the Korean Solar Energy Society
• /
• v.30 no.6
• /
• pp.28-33
• /
• 2010

Solar collectors to be applied are mainly flat-plate or vacuum tube collector which is used for hot water supply of house because of low heat value and low temperature. There are a necessity to expand applicable scope of solar collector into the industrial process heat source and air conditioner for coping with renewable energy policy of government and industrial trend. This study is to analysis the performance of PTC solar collector of concentrating type and flat-plate of non-concentrating. For this, temperature difference and heating value as insolation of air outside is measured from these two collectors mounted on 2-axial solar tracking system. It is investigated that temperature profile obtained from PTC solar collector is uniform and collecting heat per unit area is 6.8kcal/$m^2$ min which is about 3 times with compare to flat-plate collector of 2kcal/$m^2$min. Also the amount of heat to be produced from PTC solar collector is 3 Mcal/$m^2$ which is about 2 times with compare to flat-plate collector of 1.5Mcal/$m^2$ as a result of operating these two collectors during one month. Therefore, it is obtained that heat collecting performance of PTC solar collector is superior to flat-plate.

• Korean Journal of Environmental Agriculture
• /
• v.16 no.4
• /
• pp.390-393
• /
• 1997

Hormetic effects of low dose radiation were analyzed in terms of growth stimulation in radish and three cultivars of chinese cabbage. Seeds irradiated with ${\gamma}$ radiation were planted in the green house and in the experimental field. Though it varied with cultivars of tested plants, hormetic effect of low dose ${\gamma}$ radiation on an early stage of growth were shown especially in germination rates and elongation of seedlings. The height of seedlings increased in 0.2 Gy irradiated group of Seolim cultivar and radish, in 1 Gy irradiated group of Konaenggi cultivar and in 4 Gy irradiated group of Ducksung cultivar, respectively, In case of plants grown in the experimental field, prominent were the height increase of radish and Seolim cultivar in 1 Gy irradiated group and the fresh weight increase of both radish and cabbage in 4 Gy irradiated group.

• International Journal of Naval Architecture and Ocean Engineering
• /
• v.2 no.3
• /
• pp.155-170
• /
• 2010

Availability of economic and efficient energy resources is crucial to a nation's development. Because of their low cost and advancement in drilling and exploration technologies, oil and gas based energy systems are the most widely used energy source throughout the world. The inexpensive oil and gas based energy systems are used for everything, i.e., from transportation of goods and people to the harvesting of crops for food. As the energy demand continues to rise, there is strong need for inexpensive energy solutions. An offshore platform is a large structure that is used to house workers and machinery needed to drill wells in the ocean bed, extract oil and/or natural gas, process the produced fluids, and ship or pipe them to shore. Depending on the circumstances, the offshore platform can be fixed (to the ocean floor) or can consist of an artificial island or can float. Semi-submersibles are used for various purposes in offshore and marine engineering, e.g. crane vessels, drilling vessels, tourist vessels, production platforms and accommodation facilities, etc. The challenges of deepwater drilling have further motivated the researchers to design optimum choices for semi-submersibles for a chosen operating depth. In our series of eight papers, we discuss the design and production aspects of all the types of offshore platforms. In the present part I, we present an introduction and critical analysis of semi-submersibles.

• Proceedings of the SAREK Conference
• /
• 2008.06a
• /
• pp.853-856
• /
• 2008

Windows have an great effect on annual building load because windows are the weakest parts of building envelope thermally. To reduce the consumption of building energy, the thermal performance of window has to be improved in first place. Therefore this research aims to make a quantitative analysis of the heating and cooling load according to the window thermal performance using the heat load simulation program. As a result of the simulation, annual heat load is down 38% according to the decrease of U-value of window, 1.00 W/$m^2K$. and annual heat load is up 10% according to the decrease of shading coefficient, 0.20. The annual load of the window with Low-E glass is 15% lower than the window with pair glass.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.10 no.5
• /
• pp.307-315
• /
• 2015

Recently, Smart Home System(SHS) is applied in order to provide comfort, energy efficient and better security to the residence. Thus, by introducing the SHS in the house of elderly people, it is possible to provide a convenient and safe life for old people especially living alone. This paper presents the design and implementation of a low cost but yet flexible and secure smart-phone based SHS. The design is based on inter-working between Arduino board with Bluetooth and Arduino board with Ethernet shield, and the home monitor/appliances are connected to the input/output ports of this board via sensors/relays. In addition, when the old man is put on an emergency, the proposed system will automatically notify it the family. Therefore, we have implemented an inexpensive and efficient SHS for the elderly living alone by inter-working smart phones, internet server and Arduino micro-controller.

• Journal of the Korean Wood Science and Technology
• /
• v.42 no.2
• /
• pp.193-206
• /
• 2014

Residual performance of old architectural wood which has been damaged was measured using Nondestructive Evaluation (NDE). The wood Pole Tester was used to assess ultrasonic velocity inside wood and drill resistance was determined using an IML-resistograph. For ultrasonic measurements squared timber and circular timber's measurements were separately conducted with 1,300 m/s as the standard ultrasonic velocity. The standard wood samples divided into two parts; a non-sound area (below the standard), and a sound area (above the standard). Furthermore, schematization of wood was compared with results naked eye observation. The drilling resistance test was performed for both length and thickness direction in wood. The internal of the drilling was set at 30 cm (length direction), 5 cm (width direction) and 30cm (thickness direction). A non-sound area was defined as that 1) amplitude is below 20% and 2) carbonization and deterioration are related.

• New & Renewable Energy
• /
• v.16 no.2
• /
• pp.1-13
• /
• 2020

The reduction of noise from wind turbines has been studied using various methods. Some examples include controlling wind turbine blades, designing low-noise-emitting wind turbine blades, and using trailing-edge serrations. Among these methods, serration is considered an effective noise reduction method. Various studies have aimed to understand the effects of trailing-edge serration parameters. Most studies, however, have focused on fixed-wing concepts, and few have analyzed noise reduction or developed a prediction method for rotor-type blades. Herein, a noise prediction method, composed of two noise prediction methods for a wind turbine with trailing-edge serrations, is proposed. From the flow information obtained by an in-house program (WINFAS), the noise from non-serrated blades is calculated by turbulent ingestion noise and airfoil self-noise prediction methods. The degree of noise reduction caused by the trailing-edge serrations is predicted in the frequency domain by Lyu's method. The amount of noise reduction is subtracted from the predicted result of the non-serrated blade and the total reduction of the noise from the rotor blades is calculated.