• 한국신재생에너지학회:학술대회논문집
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• 2008.10a
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• pp.353-356
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• 2008

HEV(Hybrid Electrical Vehicle) is considered as one of the next generation vehicles. To develop the HEV, there must be a reliable simulator, by which the capacities of the power resources are tested, and the parameters of the HEV are optimized before developing the real model of the HEVs. This process can save the money for designing the HEV system and improve the system without experiments. Matlab Simulink is familiar to mechanical engineers and the program can simultaneously provide a system model and a controller in one program. Nowadays, the Simdriveline toolbox which is used for analysis a power-train system is applied to build a dynamic model for a HEV system. In this study, we make a HEV simulator with the Simdriveline toolbox and develop a controller. There are two simple strategies, applied to the controller. One strategy includes a power split ratio and a shift map which are created by user. Other strategy calculated an appropriate amount of resource's torque along specific results, and this is useful when users can't develop a fitting controller. The methodologies for configuring the simulator and its control system are presented in this paper.

• 한국신재생에너지학회:학술대회논문집
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• 2008.10a
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• pp.274-277
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• 2008

To evaluate high-resolution wind resources for local and coastal area with complex terrain was attemped to combine the prognostic MM5 mesoscale model with CALMET diagnostic modeling this study. Firstly, MM5 was simulated for 1km resolution, nested fine domain, with FDDA using QuikSCAT seawinds data was employed to improve initial meteorological fields. Wind field and other meteorological variables from MM5 with all vertical levels used as initial guess field for CALMET. And 5 surface and 1 radio sonde observation data is performed objective analysis whole domain cells. Initial and boundary condition are given by 3 hourly RDAPS data of KMA in prognostic MM5 simulation. Geophysical data was used high-resolution terrain elevation and land cover(30 seconds) data from USGS with MM5 simulation. On the other hand SRTM 90m resolution and EGIS 30m landuse was adopted for CALMET diagnostic simulation. The simulation was performed on whole year for 2007. Vertical wind field a hour from CALMET and latest results of MM5 simulation was comparison with wind profiler(KEOP-2007 campaign) data at HAENAM site.

• 한국신재생에너지학회:학술대회논문집
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• 2008.10a
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• pp.208-212
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• 2008

Gas hydrate has been paid attention to study for because: 1) it can be considered as a new energy resources; 2) one of reasons causing the instability of sea floor slope and 3) a factor to the climate change. Bottom simulating reflector (BSR) defined as seismic boundary between the gas hydrate and free gas zone has been considered as the most common evidence in the seismic reflection data for the gas hydrate exploration. BSR has several characteristics such as parallel to the sea bottom, high amplitude, reducing interval velocity between above and below BSR and reversing phase to the sea bottom. Moreover, instantaneous attribute properties such as amplitude envelop, instantaneous frequency, phase and first derivative of amplitude of seismic data from the complex analysis could be used to analyze properties of BSR those would be added to the certain properties of BSR in order to effectively find out the existence of BSR of the gas hydrate stability zone. The output of conventional seismic data processing for gas hydrate data set in Ulleung basin in the East sea of Korea will be used for complex analyses to indicate better BSR in the seismic reflection data. This result of this analysis implies that the BSR of the analyzed seismic profile is clearly located at the two ways time (TWT) of around 3.1 seconds.

• Journal of The Korean Society of Agricultural Engineers
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• v.50 no.6
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• pp.27-35
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• 2008

This study aims to estimate the optimal probability distribution of daily electricity generation by wind power, in order to contribute in rural green-village planning. Wind power generation is now being recognized as one of the most popular sources for renewable resources over the country. Although it is also being adapted to rural area for may reasons, it is important to estimate the magnitudes of power outputs with reliable statistical methodologies while applying historical daily wind data, for correct feasibility analysis. In this study, one of the well-known statistical methodology is employed to define the appropriate statistical distributions for monthly power outputs for specific rural areas. The results imply that the assumption of normal distributions for many cases may lead to incorrect decision-making and therefore lead to the unreliable feasibility analysis. Subjective methodology for testing goodness of fit for normal distributions on all the cases in this study, provides possibilities to consider the other various types of statistical distributions for more precise feasibility analysis.

• Journal of The Korean Society of Agricultural Engineers
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• v.50 no.6
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• pp.37-47
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• 2008

Photovoltaic power generation is currently being recognized as one of the most popular sources for renewable resources over the country. Although it is also being adapted to rural area for may reasons, it is important to estimate the magnitudes of power outputs with reliable statistical methodologies, while applying historical daily solar energy data, for correct feasibility analysis. In this study, one of the well-known statistical methodologies is employed to define the appropriate probability distributions for monthly power outputs for the selected rural area, county of Seo-san, province of Chungnam. The results imply that the assumption of normal distributions for several months may lead to incorrect decision-making and therefore lead to the unreliable feasibility analysis. Generalized beta and triangular distributions were found to be superior to normal distribution, when describing monthly probability distributions for daily photovoltaic power. Based on the appropriate distributions resulted from this study, Monte Carlo simulation technique was also applied to provide additional flexible information for the relevant decision makers. This study found out new finding that the probability distributions should be considered to make planning of the photovoltaic power system in rural village unit, in order to give reasonable economic analysis to the decision makers.

• International Journal of Advanced Culture Technology
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• v.3 no.1
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• pp.86-89
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• 2015

Sugar cane, renewable fiber resources, were used for roof tile production. Urea formaldehyde, phenol formaldehyde and isocyanate resin were used as binders in this study. Roof tile specimens with 400 mm wide, 400 mm long and 5 mm thick were prepared by compression molding. Physical and mechanical properties of the specimens were analyzed by water absorption, thickness swelling, thermal conductivity, density, modulus of rupture and modulus of elasticity. From the results, water absorption at 1 and 24 hours was 19-47 % and 38-57 %, respectively. Thickness swell at 24 hours was 15-29%. Thermal conductivity was 0.016, 0.017 and 0.019 W/m.K when using isocyanate, urea formaldehyde and phenol formaldehyde, respectively. Density of the specimens was 770-860 kg/m3. Modulus of rapture was 255-280 MPa. Modulus of elasticity was 5.1-7.6 GPa. Physical and mechanical properties of the specimens indicated that they would be applied for roof tile and construction.

• Journal of Fisheries and Marine Sciences Education
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• v.25 no.1
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• pp.167-180
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• 2013

A capstone design is regarded as one of cap courses in undergraduate engineering education because it requires most prerequisites and makes students experience real engineering design processes. There have been case studies to show how this subject should be organized, practiced, and optimized. This study shows one of the case studies by focusing offshore wind power, one of newly recognized renewable energy resources, especially targeting for the design of wind turbine foundation and submarine power cable protectors mainly because of current energy and global warming crisis. To pinpoint engineering design, the students'activities during the project and design procedures are monitored, evaluated, and recommended; hence, core factors are addressed to develop successful aim, theory, practice, and other necessities. These factors include creative problem solving abilities; recognition of engineering curriculum; selection of project theme based on significance, ripple effect, and education purpose; team organization by the full brain model; systematization of project process; realization of engineering design; and synthesis of evaluation. In the end, the aftermath and future works are discussed.

• Journal of the Korean Solar Energy Society
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• v.28 no.6
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• pp.24-32
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• 2008

This paper discussed the Feasibility study of wind power generation considering the topographical characteristics of Korea. In order to estimate the exact generation of wind power plants, we analyzed and compared wind resources in mountain areas and plain areas by introducing not only wind speed, the most important variable, but also wind distribution and wind standard deviation that can reflect the influence of landform sufficiently. According to the results of this study, generation was almost the same at wind power plants installed in southwestern coastal areas where wind speed was low as at those installed in mountain areas in Gangwondo where wind speed was high. This demonstrates that the shape parameter of wind distribution is low due to the characteristics of mountain areas, and the standard deviation of wind speed is large due to the effect of mountain winds, therefore, actual generation compared to southwestern coastal areas is almost similar in mountain areas even though wind speed is high.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.320-322
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• 2008

The international oil price now has been going up every each day, about 120 USD per a gallon April 2008, so that most of countries in the world are concern of the the shortage of petroleum and the development of new and renewable energy resources. This paper presents optimal design and operational features of stand-alone 500W PEMFC(Proton Exchange Membrane Fuel Cell) system which can be a substitute instead fossil fuel. The stack of PEMFC is composed of 35 laminated graphites, and a unit cell of the stack has electrical characteristics as below; 14W, 0.9V, 15A. The other components of BOP(Balance of Plant) are composed of hydrogen and nitrogen tanks, regulators, 3way solenoid valves, mass flow meters, etc.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.54 no.6
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• pp.303-308
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• 2005

As the cost of photovoltaic(PV) generation systems continues to decrease, utility interactive systems are becoming more economically viable. Furthermore, increases in consumer awareness correspond to a willingness to pay a premium price for clean electrical energy generated using renewable energy resources. Especially, PV generation systems, in particular, is undergoing a rapid expansion-showing an industrial growth of approximately 40$\%$ per year in the worldwide, as PV cell and systems technology improve new markets become increasingly accessible. This has resulted in an increased demand for the simulation scheme and operational technologies of utility interactive PV devices and systems. The simulation schemes that can be applied to the utility interactive PV generation systems readily and cheaply under various conditions considering the sort of solar cell, the capacity of systems and the converter system as well are strongly expected and emphasized among researchers. So far, authors have been introducing the simulation method of PV generation systems with several papers. In this paper, authors introduce the simulation way of PV generation systems using EMTP type simulators; EMTP/ATP, EMTDC/PSCAD, RTDS, with each examples. And, by connecting the voltage amplifier to the RTDS a novel simulation method which is extremely close to the real condition of PV generation system is also introduced.