• Journal of the Korean Society for Geothermal and Hydrothermal Energy
• /
• v.15 no.4
• /
• pp.1-7
• /
• 2019

Cooling using the Han River has recently been spreading. The Ministry of Trade, Industry and Energy submitted a revised enforcement ordinance to include river water in renewable energy. Therefore, it is necessary to analyze the water temperature characteristics of Han River. Especially, it is necessary to investigate the effect on hot summer. In this study, we analyzed the water temperature of the last 11 years. It is intended to utilize the Han River for building cooling in the future.

• ETRI Journal
• /
• v.39 no.2
• /
• pp.145-150
• /
• 2017

As wearable devices are powered by batteries, they need to consume as little energy as possible. To address this challenge, in this article, we propose a synergistic technique for energy-efficient approximate speech signal processing (ASSP) for wearable devices. More specifically, to enable the efficient trade-off between energy consumption and sound quality, we synergistically integrate an approximate multiplier and a successive approximate register analog-to-digital converter using our enhanced conversion algorithm. The proposed ASSP technique provides ~40% lower energy consumption with ~5% higher sound quality than a traditional one that optimizes only the bit width of SSP.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.8 no.12
• /
• pp.4451-4466
• /
• 2014

We present joint radio selection and relay scheme that delivers data from a source to a sink in heterogeneous stationary sensor networks consisting of various radio interfaces. The proposed scheme finds the optimal relay nodes and their corresponding radio interfaces that minimize energy consumption throughout the network while satisfying the end-to-end packet deadline requirement. We formulate the problem of routing through radio interface selection into binary integer programs, and obtain the optimal solution by solving with an optimization solver. We examine a trade-off relationship between energy consumption and packet delay based on network level simulations. We show that given the end-to-end deadline requirement, our routing algorithm finds the most energy-efficient routing path and radio interface across mesh hops. We demonstrate that the proposed routing scheme exploits the given packet delivery time to turn into network benefit of reducing energy consumption compared to routing based on single radio interface.

• Environmental Engineering Research
• /
• v.21 no.1
• /
• pp.74-83
• /
• 2016

The purpose of this study is to identify the driven factors affecting the changes in energy-related $CO_2$ emissions in Hebei Province of China from 1995 to 2013. This study confirmed that energy-related $CO_2$ emissions are correlated with the population, urbanization level, economic development degree, industry structure, foreign trade degree, technology level and energy proportion through an improved STIRPAT model. A reasonable and more reliable outcome of STIRPAT model can be obtained with the introducing of the Ridge Regression, which shows that population is the most important factor for $CO_2$ emissions in Hebei with the coefficient 2.4528. Rely on these discussions about affect abilities of each driven factors, we conclude several proposals to arrive targets for reductions in Hebei's energy-related $CO_2$ emissions. The method improved and relative policy advance improved pointing at empirical results also can be applied by other province to make study about driven factors of the growth of carbon emissions.

• Journal of Environmental Impact Assessment
• /
• v.23 no.1
• /
• pp.11-17
• /
• 2014

Since the Renewable Portfolio Standard (RPS) would be started in 2012, the use of renewable energy should be 11% of total energy use including bio-fuel in 2030. The economic efficiency for renewable energy in B power plant was considered with the bio-diesel, wind power and solar power. The Net Present Value (NPV) and Benefit/Cost Ratio(BC) were used for the economic efficiency with the cost and benefit analysis. In case of bio-diesel, the cost resulted from the fuel conversion and the benefit would be created with trade and environmental improvement. With regard to wind power and solar power, the construction cost would be required and benefit factors would be same as the bio-diesel. The wind power was the best of economic efficiency of renewable energy as the results of NPV and BC ratio. Whereas, the market of wind power was very popular and the techniques of wind power has been developing rapidly.

• Transactions of the Korean hydrogen and new energy society
• /
• v.33 no.4
• /
• pp.301-308
• /
• 2022

The Hydrogen Economy Promotion and Hydrogen Safety Management Act (hereinafter referred to as the "Hydrogen Economy Act") stipulates matters related to certification and cancellation of clean hydrogen by grade, and requires those who produce, import, or sell clean hydrogen to report to the Minister of Trade, Industry and Energy. In order for this system to operate smoothly, the clean hydrogen Certification system must be designed to meet international standards, and the institution operating the System must have appropriate capabilities and foundations. The clean hydrogen certification system should serve as an opportunity for Korea's domestic energy industry to take a leap forward.

• Journal of Environmental Science International
• /
• v.18 no.8
• /
• pp.919-926
• /
• 2009

Renewable energy or green energy is a hot issue in theses days. Since wind resource can be endlessly supplied by nature, researchers and common people are interested in study how to use that resource at home or company. Especially, many architects have tried to integrate wind power generator for a part of building. So in this paper, three buildings installed wind power turbine are targed to CFD analysis and these buildings are Bahrain trade center, Discovery tower, and Pearl river tower. Bahrain trade center is the first building installed real wind turbine, Discovery tower is constructing at Texas, and Pearl river tower is designed and proved by china researchers. These buildings have very different type of wind power turbine and each turbine has different conditions f3r best power generation. Therefor this paper will focus on characteristic shape of buildings, wind power turbine type, and expected purpose of construction. Moreover, CFD analysis will show wind flow pattern and wind speed while wind is passing through wind turbine of three tall buildings. CFD analysis for three buildings make comparison the wind flow patterns with experimental result.

• Journal of Energy Engineering
• /
• v.6 no.2
• /
• pp.129-136
• /
• 1997

This paper presents a new economic load dispatch considering atmospheric emissions such as NOx and SO$_2$caused by the operation of fossil-fueled thermal generation in power systems. The proposed method is described for scheduling their output of thermal power units so as to comply with total emission constraint, area emission constraint and the both of those constraints. Also, by using a trade-off curve, representing all dispatch alternatives and conflict between the emission and the fuel cost, the sensitivity analysis of the emission and the fuel cost is applied to this algorithm. By the way, this proposed method is analyzed how dispatch changes as a function of the total environmental cost, and as a function of the relative weighting of individual environmental insults, e.g, NOx and SO$_2$. By applying the proposed method to the system, the usefulness of this method is verified.

• 한국전산유체공학회:학술대회논문집
• /
• 2008.03b
• /
• pp.381-384
• /
• 2008

This paper presents an operational technique to maximize profit of a cogeneration power plant. To minimize errors in a loss and gain analysis of a cogeneration power plant, the energy sale profit in the cost-based-pool electric power trade market, the heat sale profit, and the supplementary fund profit for electric power industry are taken into consideration. The objective is to optimize the heat-electric power ratio to maximize profit of a cogeneration power plant. Furthermore, the constrained bidding technique to optimize heat-electric power ratiocan be obtained. Profits from of a cogeneration power plant are composed of three categories, such as the energy sale profit in the cost-based-pool electric power trade market, the heat sale profit, and the supplementary fund profit for electric power industry. Profits of a cogeneration power plant are varied enormously by the operation modes. The profits are mainly determined by the amount of constrained heat generation in each trading time. And the three profit categories arecoupled tightly via the heat-electric power ratio. The result of this case study can be used as a reference to a cogeneration power plant under the power trading system considered in this case.

• Resources Recycling
• /
• v.29 no.1
• /
• pp.62-69
• /
• 2020

Manufacturing processes in industrial complexes produce NOx, SOx, VOCs, which cause particulate matter (PM). Therefore, this study analyzed the characteristics of each industrial complex by using scattered public data, matched the existing particulate matter(PM) reduction technology, and proposed an optimized reduction plan. The application of matching technologies and facilities by industrial complexes based on data is able to mitigate NOx, SOx, and VOCs which cause particulate matter in the process in advance. This way can be an effective alternative in order to reduce PM in the manufacturing processes as well as industrial complexes.