• Clean Technology
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• v.17 no.4
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• pp.406-411
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• 2011

A detailed database of waste heat is built to propose energy exchange networks to recover waste energy in Pohang Steel Industrial Complex. A visualized technique is used to figure out the status of waste heat energy and to suggest potential energy exchange networks. Several energy networks are proposed in terms of temperature level, the amount of available energy, distance, and construction cost. A simple economical assessment is applied to the energy exchange networks which have higher economic potential. Their average payback period is estimated to be 2.8 years. The total amount of energy saving by constructing the proposed energy exchange networks is 4,778 TOE per year. It corresponds to 11,160 ton $CO_2$ reduction with the assumption that the recycled waste energy replaces the use of LNG in energy-demanding companies.

• KIEAE Journal
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• v.8 no.1
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• pp.19-24
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• 2008

The wind-power among the new and renewable energies uses the wind, a limitless, clean and pure energy which is available at any place. It requires low installation cost compared to the generation of other renewable energies, and is easy to operate, and furthermore, can be automated for operation. Korea has been taking a great deal of interest in the development of renewable energy generating equipment, specifically wind power generation as the nation has a nearly total reliance on imported petroleum. A measuring poll 30m high was installed at a location with an altitude of 142m above the sea level in order to measure and analyze the wind power potentiality at H University's Asan Campus, and the wind velocity and wind direction were measured for 1 year. As for the wind power resource of the area adjacent to Asan campus, the Weibull Distribution coefficient was C=2.68, K =1.29 at H30m. Weibull Distribution coefficient was modified on the basis of compensated wind velocity (=3.1m/s) at H 60m, and the energy density was $42W/m^2$. AEP 223,750 KWh was forecast based on the simulation of an 800KW grade wind turbine. It is considered that the wind power generation has to be studied further in the inland zone with low wind velocity to cope with the possible exhaustion of fossil fuel and ensure a sustainable environmental preservation.

• Journal of the Korean Institute of Intelligent Systems
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• v.24 no.5
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• pp.554-561
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• 2014

Hybrid wind Diesel stand-alone power systems are considered economically viable and effective to create balance between production and load demand in remote areas where the wind speed is considerable for electric generation, and also, electric energy is not easily available from the grid. In Wind diesel hybrid system, the wind energy system is the main constitute and diesel system forms the back up. This type of hybrid power system saves fuel cost, improves power capacity to meet the increasing demand and maintains the continuity of supply in the system. Problem we face in this system is that even after producing enough power through wind turbine system, considerable portion of this power needs to be dumped due to short term oversupply of power and to maintain the frequency within close tolerances. As a result remaining portion of total energy supplied comes from the diesel generator to overcome the temporal energy shortage. This scenario decreases the overall efficiency of hybrid power system. In this study, efficient Simulink modeling for wind-diesel hybrid system is proposed and some simulations study is carried out to verify the feasibility of the proposed scheme.

• Korean Journal of Exercise Nutrition
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• v.23 no.4
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• pp.1-5
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• 2019

[Purpose] The goal of this study was to review data on physical activity level (PAL), a crucial index for determining estimated energy requirement (EER), calculated as total energy expenditure (TEE, assessed with doubly labeled water [DLW]) divided by resting metabolic rate (RMR, PAL = TEE/RMR) in female athletes and to understand the methods of assessing athletes' EERs in the field. [Methods] For the PAL data review among female athletes, we conducted a PubMed search of the available literature related to the DLW method. DLW studies measuring TEE and RMR were included for the present review. [Results] Briefly, the mean PAL was 1.71 for collegiate swimmers with moderate training, which was relatively low, but the mean PAL was 3.0 for elite swimmers during summer training camp. This shows that PAL can largely vary even within the same sport depending on the amount of training, and the differences in PAL were remarkable depending on the sport. Aside from the DLW method, there is currently no research tool related to athletes' EERs that can be used in the field. [Conclusion] Briefly, the mean PAL was 1.71 for collegiate swimmers with moderate training, which was relatively low, but the mean PAL was 3.0 for elite swimmers during summer training camp. This shows that PAL can largely vary even within the same sport depending on the amount of training, and the differences in PAL were remarkable depending on the sport. Aside from the DLW method, there is currently no research tool related to athletes' EERs that can be used in the field.

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

• Solar Energy
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• v.18 no.2
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• pp.19-29
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• 1998

Solar energy is a quantitatively unlimited, clean and non-pollutant source. It has a great potential for industrial commercial usages. For example, solar hot water system for domestic usage has been very popular in many counties. In Korea, the industries consume 47.7% of the total national energy, and the manufacturing sector uses 91.5% out of it. The main energy resoures available in Korea are oils, coals, and gases. There have been continuous efforts among the industries to reduce such energy consumptions by using alternative energy resources, such as solar energy, yet the technology has limited its proper applications to a level of satisfaction. In some advanced countries, research and development programs in solar energy applicable to the industrial usages are very active, and some systems are in the commercial market. Therefore, this paper describes the status and the feasibility for high-efficiency evacuated solar collector which was anticipated to applied for industrial process heat as an alternative of fossil energy.

• Journal of Nutrition and Health
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• v.40 no.2
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• pp.172-181
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• 2007

This study was performed to evaluate served menu in Korean temples. Among available temples in the nation, 34 temples were carefully selected considering location and the gender characteristics. A five consecutive day menu was collected to analyse by interview between Jan 2004 and Aug 2004. Mean energy content of menu was 1633.8 kcal, with 67.3% of energy supplied by carbohydrate, 14.8% by protein and 17.9% by fat. Beans and bean products were the major contributing dishes for most nutrients. Contents of most nutrients except energy, protein and vitamin B were higher than RDA. Nutrient adequacy ratio (NAR) were 0.9-1.0 and mean adequacy ratio (MAR) was 0.9 for temples. Total number of dishes from menu was 7.3. Dietary variety score (DVS) was 26.4 and buddhist monk temples offered more diverse foods than buddhist nun temples. KDQI (Korean diet Quality Index), overall diet quality index were 0.67 and those of buddhist nun temples were better than those of buddhist monk temples. From the result of this study it was concluded that the temple diet is nutritionally well balanced, rich in dietary fiber and low in cholesterol. So it can be a healthy diet for the modern person. This is the very first study attempting the nationwide investigation of temple diet in Korea. It will be used as fundamental data to improve quality of diet to prevent modern chronic disease.

• Transactions of the Korean Society of Mechanical Engineers
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• v.9 no.6
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• pp.714-724
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• 1985

Two-phase(air-solid, air-liquid droplet) turbulent round jet has been analyzed numerically using two equation turbulence model. The mean motion of suspending particles in air has been treated as the secondary fluid with virtual density and eddy viscosity. In this paper, the local mean velocity of secondary fluid is not assumed to be the same as that of the primary one. Dissipation rate of turbulent kinetic energy which arises because the particles can not catch up with the turbulent fluctuations of the primary fluid has been modelled by using the concept of Kolmogorov's spectral energy transfer. Numerical computations were performed for flows with different volume fraction of the dispersed phase and the diameter of particle. Results show that the total rate of turbulent energy dissipation, turbulent intensities and spreading rate of jets are reduced by the increase of volume fraction of dispersed phase. However it does not show consistent tendency with increasing the particle diameter. This investigation also shows that presence of particles in the fluid modifies the structure of the primary fluid flow significantly. Predicted velocity profiles and turbulence properties qualitatively agree with available data.

• Journal of the Korean Solar Energy Society
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• v.36 no.3
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• pp.9-16
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• 2016

This paper discusses a refined model for investigating the micro-mechanical behavior of beam-like structures, which are composed of various elastic moduli and complex geometries varying through the cross-section directions and are also periodically-repeated and heterogeneous along the axial direction. Following the previous work (Lee and Yu, 2011), the original three-dimensional static problem is first formulated in a unified and compact form using the concept of decomposition of the rotation tensor. Taking advantage of the smallness of the cross-sectional dimension-to-length parameter and the micro-to-macro heterogeneity, while also performing homogenization along the dimensional reduction simultaneously, the variational asymptotic method is rigorously used to construct a total energy function, which is asymptotically correct up to the second order. Furthermore, through the transformation procedure based on the pure kinematic relations and the linearized equilibrium equations, a generalized Timoshenko model is systematically established. For the purpose of dealing with realistic and complex geometries and constituent materials at the microscopic level, this present approach is incorporated into a commercial analysis package. A few examples available in literature are used to demonstrate the consistency and efficiency of this proposed model, especially for the structures, in which the effects of transverse shear deformations are significant.

• Korean Journal of Soil Science and Fertilizer
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• v.4 no.1
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• pp.33-40
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• 1971

Using radioactive $^{40}K$ in potassium, a study was conducted to evaluate the potassium supplying power of different soil types developed on different parent materials. A conversion factor based on two parameters namely $\frac{available\;K_{soil}}{total\;K_{soil}}$ and $\frac{K_{plant}}{K_{soil}}$ was developed and found to be closely related to plant response. According to this characterization soils derived from the various parent materials were ranked as basalt >Silla series>gneiss>porphyry>granite${\gg}$schist. From the point of view of potassium response as measured by yield as similar response pattern was observed. That is, soils derived from basalt to be most responsive as compared to the other soils. The variations among the soils may be accounted for to their potassium bearing mineralogical composition and their stability.