• Tunnel and Underground Space
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• v.19 no.2
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• pp.77-85
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• 2009

Flexible and lined segment air-tight tunnelling technology for Compressed Air Energy Storage-Gas Turbine(CAES-G/T) power generation was introduced. The distinguished characteristics of the air-tight tunnel system can be summarized by two facts. One is that the high inner pressure due to compressed air is sustained by surrounding rock mass with allowing sufficient displacement of lining segment. The other is that the air-tightness of storage tunnel was enhanced by adopting a specially designed rubber sheet. The flexible lined air-tight underground tunnel can be constructed at a comparatively shallow depth and near urban area so that the locally distributed CAES-G/T power generation can be accomplished. In addition, this air-tight tunnelling technology can be applied to a variety of energy underground storage tunnels such as Compressed Natural Gas(CNG), Liquifed Petroleum Gas(LPG), DeMethyl Ether(DME) etc.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.4
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• pp.1765-1794
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• 2019

Genetic Programming (GP) is an intelligence technique whereby computer programs are encoded as a set of genes which are evolved utilizing a Genetic Algorithm (GA). In other words, the GP employs novel optimization techniques to modify computer programs; imitating the way humans develop programs by progressively re-writing them for solving problems automatically. Trial programs are frequently altered in the search for obtaining superior solutions due to the base is GA. These are evolutionary search techniques inspired by biological evolution such as mutation, reproduction, natural selection, recombination, and survival of the fittest. The power of GAs is being represented by an advancing range of applications; vector processing, quantum computing, VLSI circuit layout, and so on. But one of the most significant uses of GAs is the automatic generation of programs. Technically, the GP solves problems automatically without having to tell the computer specifically how to process it. To meet this requirement, the GP utilizes GAs to a "population" of trial programs, traditionally encoded in memory as tree-structures. Trial programs are estimated using a "fitness function" and the suited solutions picked for re-evaluation and modification such that this sequence is replicated until a "correct" program is generated. GP has represented its power by modifying a simple program for categorizing news stories, executing optical character recognition, medical signal filters, and for target identification, etc. This paper reviews existing literature regarding the GPs and their applications in different scientific fields and aims to provide an easy understanding of various types of GPs for beginners.

• International Journal of Highway Engineering
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• v.13 no.4
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• pp.159-166
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• 2011

Green house gas emissions are increasing as development of the industrial economy of the international community. Many countries in the world are endeavoring to reduce green house gas emissions under severe climate change. In order to protect grobal warming, government is trying to reduce green gas emissions under "Low Carbon Green Growth Policy" and investing climiate-firendly industries such as renewable energy harvesting. Renewable energy has been rapidly developing as a result of investment for development technology of using natural energy such as solar, wind, tidal, etc. There are lots of waste energy in the road space. However, nobody is not interested in waste energy from the road space. This paper present a fundamentally experimental study of energy harvesting technique to use waste energy in the road. The waste energy in the road is covered a pressure and impact of vehicles on the road, the radiant heat from asphalt pavement, road noise and vibration etc. In this study, an energy harvesting device using piezoelectric element is proposed and various tests are conducted to investigate a characteristic of this device as function of impact loading based on piezoelectric effect behavior. This paper shows the energy harvesting results of the device using domestic piezoelectirc element as a function of impact load size and pavement types.

• The Journal of Natural Sciences
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• v.8 no.2
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• pp.119-127
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• 1996

The effect of sodium hydroxide treatment on some physicochemical properties of zeolite mordenite mineral was studied with chemical analyses, powder X-ray diffraction, thermal analyses, infrared analysis, measurement of carbon dioxide adsorption and gas chromatography. Mordenite mineral from tuffaceous rocks in Yeongil and Wolsung area was used as a starting material and treated with 0.1-5N NaOH aqueous solution at about $95^{\circ}C$ in the water bath for three hours.At the concentration of sodium hydroxide below 0.5N, all chemical compositions in the tuff were virtually insoluble and the mordenite structure did not change. At the concentration above 1N, the chemical compositions such as silica, alumina, etc., were dissolved. The dissolution ratio of silica was lager than that of alumina, and the ratio of silica to alumina in the tuff decreased sharply in the concentration range of 2 to 3N. Intensity of X-ray diffraction peak of mordenite (202) plane and the adsorbed amount of carbon dioxide also decreased with the increasing concentration of sodium hydroxide above 1N. These decreases corresponded to the degree of mordenite structure collapsed.The separation of gas chromatography of nitrogen, oxygen and carbon monoxide was not affected by the sodium hydroxide treatment, but elution peaks of methane and krypton tended to be broadened and their retention time was shortened. The elution peaks of both methane and krypton tended to be overlapped with those of nitrogen and oxygen.

• Korean Chemical Engineering Research
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• v.52 no.6
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• pp.796-806
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• 2014

The key for the commercial deployment of IGCC power plants or chemical (methanol, dimethyl ether, etc.) production plants based on coal gasification is their economic advantage over plants producing electricity or chemicals from crude oil or natural gas. The better economy of coal gasification based plants can be obtained by co-production of electricity and chemicals. In this study, we carried out the economic feasibility analysis on the process of co-producing electricity and DME (dimethyl ether) using coal gasification. The plant's capacity was 250 MW electric and DME production of 300,000 ton per year. Assuming that the sales price of DME is 500,000 won/ton, the production cost of electricity is in the range of 33~58% of 150.69 won/kwh which is the average of SMP (system marginal price) in 2013, Korea. At present, the sales price of DME in China is approximately 900,000 won/ton. Therefore, there are more potential for lowering the price of co-produced electricity when comparing that from IGCC only. Since the co-production system can not only use the coal gasifier and the gas purification process as a common facility but also can control production rates of electricity and DME depending on the market demand, the production cost of electricity and DME can be significantly reduced compared to the process of producing electricity or DME separately.

• Journal of Advanced Research in Ocean Engineering
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• v.3 no.1
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• pp.1-14
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• 2017

The safety analysis of an earthquake is carried out during the operation of a subsea pipeline and an onshore pipeline. Several cases are proposed for consideration. In the case of a buried pipeline, permanent ground deformation by the earthquake and an increase of internal pressure by the acceleration of the earthquake should be considered. In the case of a subsea pipeline, a bending moment is caused by liquefaction of the backfill material on a trenched seabed, etc., which results in a high bending moment of the buried pipeline. The bending moment causes the collapse of the subsea pipeline or a leak of crude oil or gas, which results in economic loss due to enormous environmental contamination and social economic loss owing to operation functional failure. Thus, in order to prevent economic loss and operation loss, structurally sensitive design with regard to seismic characteristics must be performed in the buried pipeline in advance, and the negative impact on the buried pipeline must be minimized by conducting a thorough analysis on the seabed and backfilling material selection. Moreover, it is proposed to consider the selection of material properties for the buried pipeline. A more economical review is also required for detailed study.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.200.1-200.1
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• 2011

Underground air is a special energy source in Jeju and distributes lava cave, pyroclastic, open joint, and crushing zone. A possible area to utilize underground air is 85% of Jeju except to the nearby area of Sambang Mt. and 25m high coastal area from sea level. In Jeju, underground air is used for heating agricultural facilities such as greenhouse cultivated mangos, Hallbong and mandarin orange, pigsty, mushroom cultivation house, etc. and fertilizing natural $CO_2$ gas by suppling directly into agricultural facilities. But this heating method causes several problem because the underground air has over 90% relative humidity and is inadequate in heating for crops. Mangos are the most widely grown tropical fruit trees and have been cultivated since 1993 in Jeju. In Jeju, the cultivating area is about 20ha and amount of harvest is 275ton/year in 2010. In this study, the heat pump system using underground air as heat source was installed in mangos greenhouse which area is $495m^2$. The capacity of heat pump system and heat storage tank was 10RT, 5ton respectively and heating effect and heating performance of the system were analysed.

• Environmental Engineering Research
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• v.21 no.4
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• pp.409-419
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• 2016

As a major energy consumption province, the issue about the carbon emissions in Hebei Province, China has been concerned by the government. The carbon emissions can be effectively reduced due to a more rational energy consumption structure. Thus, in this paper the constraint of low carbon emissions is considered as a foundation and four energies--coal, petroleum, natural gas and electricity including wind power, nuclear power and hydro-power etc are selected as the main analysis objects of the adjustment of energy structure. This paper takes energy cost minimum and carbon trading cost minimum as the objective functions based on the economic growth, energy saving and emission reduction targets and constructs an optimization model of energy consumption structure. And empirical research about energy consumption structure optimization in 2015 and 2020 is carried out based on the energy consumption data in Hebei Province, China during the period 1995-2013, which indicates that the energy consumption in Hebei dominated by coal cannot be replaced in the next seven years, from 2014 to 2020, when the coal consumption proportion is still up to 85.93%. Finally, the corresponding policy suggestions are put forward, according to the results of the energy structure optimization in Hebei Province.

• Journal of Ocean Engineering and Technology
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• v.27 no.1
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• pp.43-50
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• 2013

This paper presents a structural design review of a marine loading arm used for the fluid transfer of a liquid cargo from a ship or offshore plant. The marine loading arm is installed on a ship, offshore plant, or jetty in order to load or unload liquid cargo such as crude oil, liquefied natural gas (LNG), chemical products, etc. The structural design of this marine loading arm is obliged to comply with the design and construction specifications regulated by the oil companies and international marine forum (OCIMF). In this paper, the structural safety of the initial design for the marine loading arm is evaluated for the design load conditions required by various operational modes. The evaluated results based on a finite element analysis (FEA) are reviewed in relation to the OCIMF specifications.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.172-176
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• 2009

We developed a program, "CogenSim-$\mu$," to simulate the operation of micro-combined heat and power (${\mu}CHP$) system. The CogenSim-$\mu$ can reflect the variation of energy efficiency by handling the real-time loads (heat and power) fluctuation. The result obtained using this program was compared with the real operation of 30 kWe gas engine driven ${\mu}CHP$. It was found that the CogenSim-$\mu$ could predict the amount of generated-power, recovered-heat and consumed-fuel with the error less than 3%, and heat and power efficiency with the error less than 4%. The CogenSim-$\mu$ reconstructed the profile of on-off cycle, which represented the operation of a facility, with more than 93% accuracy. The CogenSim-$\mu$ can reflect the effects of various factors such as size of thermal storage tank, desired temperature of reservoir water, natural frequency of generator, etc. As a result, the CogenSim-$\mu$ can be used to optimize the ${\mu}CHP$ operation.