• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.5
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• pp.181-186
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• 2019

In order to reduce the fossil fuels consumed in conventional commercial independent diesel generators in the same environment as the island area, it is necessary to develop a photovoltaic system that will bear more than 40% of the independent system capacity. For this development, it is necessary to develop a high-capacity inverter that can improve the stability of the independent system installed in the island area and supply high-quality power to the load. In addition, the EMS power generation control system for the independent grid photovoltaic power generation system is a parallel operation power control system of the diesel generator connected with the solar power generation system. It controls the output of the diesel generator according to the load ratio and the solar power generation, A stable supply system is needed. This independent grid photovoltaic generation system can increase the solar power supply to the independent system area and increase the power stability of the independent system and further reduce the use of fossil fuel due to the ineffective power control of the independent system. It is expected that the economy will be secured early.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.4
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• pp.605-612
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• 2017

One of the biggest environmental issues that our world has been facing is climate change. In order to cope with such environmental issues, the world is putting a great deal of effort into energy conservation. The building sector, in particular, consumes 36% of the energy consumed worldwide and emits considerable amount of greenhouse gases. Therefore, introduction of renewable energies in the building sector is highly recommended. Renewable energy sources that can be utilized in the building sector include sunlight, solar heat, geothermal heat, fuel cells and wind power. The wind power generation system which converts wind energy into electrical energy has advantages in that wind is an unlimited and pollution-free resource. It is suitable to be connected to existing buildings because many years of operational experience and the enhanced stability of the system have made it possible to downsize the electrical generator. In case of existing buildings, it is necessary to consider the live loads of the buildings to connect the wind power generation system. This paper, through the connection of the wind power generation with existing buildings, promotes reduction of greenhouse gas emissions and energy independence by reducing energy consumption in the building sector. In order to connect the wind power generation system with an exciting building, the live load of the building and the area of the rooftop should be considered. The installable model is selected by comparing the live load of the building and the load of the wind power generation system. The maximum number of the wind turbines that can be installed is obtained by considering the separation distance between the wind turbines within the area of the rooftop. Installations are divided into single installations and multiple installations of two different types of wind turbines. After determining the maximum installable number, the optimal model that can achieve the maximum annual power generation will be selected by comparing the respective total annual amount of the power generation of different models.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.713-716
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• 2008

This paper presents an automatic back-light brightness control system for mobile displays. One of the most important factors in mobile display is the power consumption due to the limited and movable power source. More than 80% of power of the LCD display is consumed by LED bark-light unit (BLU). The target brightness also becomes higher because of its moving picture and high resolution image, so there are some side effects for not only excessive power consumption but also ergonomic inconvenience in dark environment. To prevent this discomfort and reduce power consumption, this paper proposes automatic brightness control (ABC) technique in mobile displays. Developed system contains TFT-LCD panel with built-in photo sensor, driver IC capable of controlling photo sensor, and BLU. Since the photo sensor array built in panel detects automatically outdoor ambient light intensity, the power of BLU in dark environment is reduced. Developed ABC system showed reduced power consumption of 50% in dark environment. We believe that the proposed system is very useful to control power of mobile TFT-LCD.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.36C no.12
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• pp.27-35
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• 1999

In a typical spread spectrum system, parallel correlator occupies a large fraction of power consumption because of the large number of accumulators in the system. In this paper, a novel accumulator is proposed that can reduce the power consumption in the parallel correlator. The proposed accumulator counts the numbers of 1 of the incoming input data. The counted values are weighted and added together to obtain the final correlation value only at the end of the accumulation. The proposed accumulator has been designed and simulated by CADENCE Verilog-XL and synthesized by SYNOPSYS Design Compiler with $0.6{\mu}m$ standard cell library. Power consumption results have been obtained from EPIC PowerMill simulations. Simulation results are very encouraging. First, the power dissipation is reduced by 22% and the maximum operating frequency is increased by 323%. In addition, the parallel correlator using the proposed accumulators consumed less power than the conventional active parallel correlators by 22%, and less power than the conventional passive correlator by 43%.

• Journal of the Korean Society for Railway
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• v.12 no.2
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• pp.254-259
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• 2009

DC transit system has been adopted in the metropolitan area, Korea since 1974. Electric multiple (EMU) in this system always reiterates that acceleration and retardation. When EMU decelerates using electric breaking, regenerative power occurs. Regenerative power can be consumed in vicinity EMU on the same line or in resistor. If DC transit system has inverter for reusing regenerative power, Energy efficiency in DC transit system and the replacement cycle of brake shoe in EMU will be increased and dust due to mechanical braking decreased. This paper present the developed inverter for regenerative power and its test equipment. Test for developed inverter is performed at test equipment and is divided into three items, which are regeneration mode, active filter mode, and system link test.

• Journal of Digital Convergence
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• v.11 no.12
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• pp.447-452
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• 2013

Berkley Media Access Control (B-MAC) protocol is one of the well-known MAC protocols, which uses adaptive preamble sampling scheme and is designed for wireless sensor networks (WSN). In this paper, we are reviewed about security vulnerability in B-MAC, and analyzed the power which is consumed at each stage of B-MAC protocol according to vulnerability of denial of sleep(DoS) and replay problem. From our analytical results, it can be considered the need of power efficient authentication scheme which provides the reliability, efficiency, and security for a general B-MAC communication. This is the case study of possible DoS vulnerability and its power consumption in B-MAC.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.12
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• pp.4760-4765
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• 2010

Time out-medium access control (T-MAC) protocol is one of the well-known MAC protocols designed for wireless sensor networks (WSN), and is proposed to enhance the poor performance of the S-MAC protocol. In this paper, we are reviewed about security vulnerability in T-MAC, and analyzed the power which is consumed at each stage of T-MAC protocol according to vulnerability of denial of service (DoS) and replay problem. From our analytical results, it can be considered the need of power efficient authentication scheme which provides the reliability, efficiency, and security for a general T-MAC communication. This is the case study of possible DoS vulnerability and its power consumption in T-MAC.

• Journal of Environmental Health Sciences
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• v.42 no.3
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• pp.224-233
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• 2016

Objectives: The purpose of this study was to evaluate the relationship between residential surroundings, such as a power plant, steel mill and petrochemical facilities, and urinary arsenic concentrations in Chungcheongnam-do Province, Korea. Methods: Stratified by fish consumption and residential district, median and maximum block sampling was applied. A total of 346 spot urine samples were speciated for $As^{5+}$, $As^{3+}$, monomethylarsonic acid(MMA), dimethylarsonic acid (DMA) and arsenobetaine (AsB). Exposure assessment was based on questionnaires including data on sex, age, current tobacco use, fish consumption, type of water consumed, and occupational category. Results: Urinary $As^{5+}+As^{3+}+MMA+DMA$ concentrations of people living in the vicinity of a power plant ($GM=50.39{\mu}g/g$) were 61% higher than those of people living in the inland area according to median block sampling. Urinary $As^{5+}+As^{3+}+MMA+DMA+AsB$ concentrations of people living in the vicinity of industrial complex area were higher than those of people living in the inland area according to block sampling by median and maximum. Conclusion: Urinary arsenic concentrations of people living in vulnerable areas such as around industrial complexes, especially power plants, were higher than those of people living in an inland area.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.11
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• pp.57-68
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• 2013

The market for distributed power generation based on renewable energy is increasing, particularly for standalone mini-grid applications in developing countries with limited energy resources. Stand-alone power systems (SAPS) are of special interest combined with renewable energy design in areas not connected to the electric grid. Traditionally, such systems have been powered by diesel engine generator sets (DEGS), but also hybrid systems with photovoltaic and/or wind energy conversion systems (WECS) are becoming quite common nowadays. Hybrid energy systems can now be used to generate energy consumed in remote areas and stand-alone microgrids. This paper describes the design, simulation and feasibility study of a hybrid energy system for a stand-alone power system. A simulated model is developed to investigate the design and performance of stand-alone hydrogen renewable energy systems. The analysis presented here is based on transient system simulation program (TRNSYS) with realistic ventilation load of a large store. Design of a hybrid energy system is site specific and depends on the resources available and the load demand.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.7
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• pp.71-79
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• 2004

Packet-type data transmission is characterized by the continuous transmission of massive data with relatively constant rate. In such transmission, the dynamic power consumed on buses is influenced by the sequence of transmitted data. A new coding scheme called Sequence-Switch Coding (SSC) is proposed in this paper. SSC reduces the number of bus transitions in the transmission of packet-type data by changing the sending order of the data. Some simple algorithms are presented, In. The simulation results show that SSC outperforms the well-known Bus-Invert Coding with these algorithms. SSC is not a specific algerian but a method to reduce the number of bus-transitions. There could be lots of algorithms for realizing SSC. The variety of SSC algorithms provides circuit designers a wide range of trade-off between performance and circuit complexity.