• Journal of the Korean Society for Railway
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• v.15 no.4
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• pp.408-412
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• 2012

Recently, new climate change mechanism after 2020 year has been accepted with the parties, and so government is pushing ahead the GHG reduction policies to achieve the effective results. Especially, it is essential to enhance the role of railroad in the public traffic system as well as to develop new cars with high energy efficiency for the GHG reduction of transportation sector. Thus, the calculation method of GHG emission of railroad should be established to manage the emission continuously. In this study, the calculation method of GHG emission of railroad was defined with Tier level considering its emission sources to refer to 2006 IPCC guideline for national GHG inventories. Also, the GHG emission of railroad at Tier 1 level was investigated using the activity data related to the amount of diesel and electricity consumption from 2008 to 2010. As a result, total GHG emission in 2010 was about 2,060 thousands ton CO2e, which have 73% of electricity and 27% of diesel. In future, the plans on the GHG reduction of railroad will be accomplished by the analysis of the detailed trends on the basis of the emission management of Tier 3 level under operating patterns. Therefore, it is important to develop the specific GHG emission factors of railroad in advance.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.3
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• pp.547-554
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• 2018

Wind energy is widely recognized as one of the cheapest forms of clean and renewable energy. In fact, in several countries, wind energy has achieved cost parity with fossil fuel-based sources of electricity generation for new electricity generation plants. Offshore wind energy development promises to be a significant domestic renewable energy source for the target of korea government 3020 plan. A pivotal activity during the development phase of a wind project is wind resource assessment. Several approaches can be categorized as three basic scales or stages of wind resource assessment: preliminary area identification, area wind resource evaluation, and micrositing. This study is to estimate the wind power capacity of chonnam province offshore area using three basic stages based on the six meteorological mast data. WindPRO was used, one of a well-known wind energy prediction programs and based on more than 25 years of experiences in development of software tools for wind energy project development. The design results of offshore wind power generation capacity is calculated as total 2.52GW with six wind farms in chonnam offshore area.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.47 no.1
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• pp.24-34
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• 2015

Domestic companies supplying electricity must increase obligatory duty to use renewable energy annually. If not met with obligatory allotment, the electricity-supply companies must pay RPS (Renewable Portfolio Standards) penalty. Although the power plants using a pulverizing coal firing boiler could co-fire up to around 3 per cent with wood pellets mixed in with coal feedstock without any major equipment revamps, they recorded only about 60 per cent fulfillment of RPS. Consequently, USD 46 million of RPS penalty was imposed on the six power supplying subsidiaries of GENCOs in 2014. One of the solutions to reduce the RPS penalty is that the power supply companies adopt the co-firing of torrefied lignocellulosic biomass in coal plants, which may contribute to the use of over 30 per cent of torrefied biomass mixed with bituminous coals. Extra binder was required to form pellets using torrefied biomass such as wood chips, PKS (Palm Kernel Shell) and EFB (Empty Fruit Bunch). Instead of corn starch, 30, 50 and 70 per cent of Larix saw dusts were respectively added to the torrefied feedstocks such as Pinus densiflora chips, PKS and EFB. The addition of saw dusts led to the decrease of the calorific values of the pellets but the forming ability of the pelletizer was exceedingly improved. Another advantage from the addition of saw dusts stemmed from the reduction of ash contents of the pellets. Finally, it was confirmed that torrefied oil palm biomass such as PKS and EFB could be valuable feedstocks in making pellets through improved binding ability.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.02a
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• pp.140-142
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• 2004

Since the April of 1978, Korea has strongly relied on the nuclear energy for electricity generation. As of today, eighteen nuclear power plants are in operation and ten are to be inaugurated by 2015. The installed nuclear capacity is 15, 716 MW as of the end of 2002, representing 29.3% of the nation's total installed capacity. The nuclear share in electricity remains around 38.9 at the end of 2002, reaching at the level of 119 billion kWh's. New power reactors, KSNP's (Korea Standard Nuclear Power Plant) are fully based on the domestic technologies. More advanced reactors such as KNGR (Korea Next Generation Reactor) will be commercialized soon. Even though the front end nuclear cycle enjoys one of the best positions in the world, there have been some chronical problems in the back end fuel cycle. That's the one of the reason why we need more active R&D programs in Korea and active international and regional cooperation in this area. The everlasting NIMBY problem hinders the implementation of the nation's radioactive waste management program. We expect that the storage capacity for the LILW(Low and Intermediate Level radioactive Waste) will be dried out soon. The situation for the spent fuel storage is also not so favorable too. The storage pools for spent fuel are being filled rapidly so that in 2008, some AR pools cannot accommodate any more new spent nuclear fuels. The Korean Government in strong association with utilities and national academic and R&D institutes have tried its best effort to secure the site for a LILW repository and a AFR site. Finally, one local community, Buan in Jeonbook Province, submitted the petition for the site. At the end of the last July, the Government announced that the Wido, a small island in Buan, is suitable for the national complex site. The special force team headed by Dr IS Chang, president of KAERI teamed with Government officials and many prominent scholars and journalists agreed that by the evidences from the preliminary site investigation, they could not find any reason for rejecting the local community's offer.

• Fire Science and Engineering
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• v.31 no.2
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• pp.61-73
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• 2017

The Fukushima Nuclear Disaster in 2011 and California Power Failure in 2001 are examples of the importance of the power plant safety management that caused huge national loss with a power-related mass casualty incident. In a situation where humans cannot live without electricity, efforts to strengthen the systematic firefighting safety management in power plants that produce electricity with large amounts of hazardous materials as fuel, such as nuclear energy, coal and gas, are essential to protect life and prevent property loss and stable economic growth from fire explosion accident or radiation leak due to the negligence of safety management and natural disasters such as earthquakes, which has recently become an issue. This study examined the operating situation of firefighting safety management in power plants with firefighting officials employed by five power generation companies including Korea Southern Power Co., Ltd. and Korea Hydro & Nuclear Power Co. Ltd., which are in charge of the domestic power supply. As a result, for the systematic firefighting safety management of power plants, improvement plans were drawn, including the development of an effective business manual and a comprehensive management system, the substantiality of firefighting safety education, and the strengthening of seismic designs to prepare for earthquakes.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.35 no.6
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• pp.631-638
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• 2022

Microgrid, which enables the production and consumption of electricity to be done independently on a small scale, has been studied on one of the solutions of reinforcement for flexibility of electronic system. This study examined the application effect of new microgrid by applying hybrid battery in electric power storage device. We designed the system to highlight the advantage of each battery and complement the disadvantage by using hybrid system with Lithium-ion battery and interval Redox flow battery. It runs with lithium-ion battery during the initial startup while the Redox flow battery operates for a long time at the end of excessive period, and it enables a discharge of Lithium-ion and Redox flow battery at the same time when the load has a large output. We chose Maldives as a subject of this study for organizing and optimizing independent microgrid. Maldives is the country to accomplish 100% domestic electricity in South Asia, but the whole electric power is supplied through diesel generation imported fossil fuel. We organized and optimized microgrid for energy independence on Malahini island to solve Maldives energy cost problem and global energy environment matters. We analyzed the daily power supply and accumulated the power supply from September 18, 2018~February 11, 2019. The accumulated power supply was about 120.4 MWh and the daily power supply was about 800~1000 kWh. Based on the collected information, we divided the cases into three models which are only diesel generator, solar generator as well as diesel generator, and solar+ESS+diesel generator. We analyzed the amount of oil consumption compared to the cost of construction and power output. The result showed that solar+ESS+diesel generator was most economically feasible. As well, we obtained that our considering hybrid battery system reduced the fuel consumption for diesel power generation about 10~15%.

• Korean Journal of Construction Engineering and Management
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• v.18 no.2
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• pp.91-98
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• 2017

Due to climate change, countries around the world are actively investing in renewable energy, reducing fossil fuel use. 23.7% of world electricity is supplied by renewable energy. As the technology continues to develop, it is in a level to compete in terms of power generation cost, and investment conditions are improving. However, investment in renewable energy projects is not easy. This study analyzed trends of domestic and international researches on economics assessment applying real options analysis to investment decisions of hydro, solar, and wind power projects, which account for a large portion of renewable energy. This study provides (1) the difference between the traditional economic method and the real options analysis, (2) the application process, and (3) the uncertainty elements and option type of the renewable energy project presented by many studies. The real options analysis is suitable for the detailed investment strategy by considering the uncertainties of the renewable energy project and applying the option to improve the profit or to avoid the risk.

• Informatization Policy
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• v.17 no.4
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• pp.44-60
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• 2010

Under the continuing economic growth without increase in employment, issues regarding the impact of IT investment on demand for labor have been continuously raised. Under the circumstance, this study carried out an empirical analysis on the impact of IT investment on employment with a sample of 498 businesses whose domestic sales for the period of six years from 2003 to 2008 are KRW 100 billion or above. The result of the analysis found that IT investment increases employment in most of the industries except for some of the service sectors. In the manufacturing industry, more IT investment increased employment but decreased the flexibility in demand for labor; therefore, IT investment has a substitutional relationship with low-skilled labor and a complementary relationship with high-skilled labor. In the areas of electricity, gas and construction, employment increased as IT investment increased, with the greatest flexibility in demand for labor. In the service industry, increase in IT investment led to more employment and higher flexibility in producer services only. On the other hand, there was no meaningful relationship found between IT investment and employment in the areas of distribution services and social services.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.1
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• pp.1-8
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• 2010

The ultrafashionable machinery that require high quality electricity power has been daily come into being. Because domestic power system has been larger and more complicated in accordance with raising power demand by power market requirement. Because of these power market situations, The FACTS (Flexible AC Transmission System) which is power transmission system for the next generation to meet flexible supply the power and reliability has been applied. If they, compensators and FACTS, are used inter-efficiently in range that does not affect the stability and a badly influence the security, they might be increase in the voltage stability of system, supply reliability and also achieve the voltage control in a suddenly changed power system. Therefore we describe and suggest on this treatise that a plan for coordination control between UPFC, Shunt elements (Sh. Capacitors & Sh. Reactors) among compensators and also describe the method to keep or control the voltage of power system in allowable ranges. The method follows that, we used characteristics of each equipment, UPFC would be also settled to keep the identified voltage range in change of load bus, Shunt elements also would be settled to supply the reactive power shortage in out of operating range of UPFC to cope actively with change of the power system. As the result of simulation, it is possible to keep the load bus voltage in limited range in spite of broad load range condition. This helps greatly for the improvements of supply reliability and voltage stability.

• Journal of the Korean Society for Advanced Composite Structures
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• v.5 no.3
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• pp.8-16
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• 2014

Torque control method and turn of nut method are specified as clamping method of high strength bolts in the steel construction specifications. Quality control of torque coefficient is essential activity because torque control method, which is presently adopted as clamping method in domestic construction sites, is affected by variation of torque coefficient. The clamping of torque shear bolt is based on KS B 2819. It was misunderstood that the tension force of the TS bolt was induced generally at the break of pin-tail specified. However, the clamping forces on slip critical connections do not often meet the intended tension, as it considerably varies due to torque coefficient dependent on the environmental factors and temperature variables despite the break of the pin tail.This study was focused to evaluate the effect of environmental factors and errors of installing bolts during tightening high strength bolts. The environmental parameters were composed of 'wet' condition, 'rust' condition, 'only exposure to air' condition. And the manufacture of trial product was planned to identify the induced force into the bolts. The algorithm for a trial product was composed of the relation between electricity energy taken from torque shear wrench and tension force from hydraulic tension meter.