• Proceedings of the KSR Conference
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• 2005.11a
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• pp.119-124
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• 2005

Decision of operation performance mode to minimize the energy consumption of urban rail vehicle. This paper analyses how much acceleration and deceleration of urban rail vehicle should be applied andhow to choose an operation mode to minimize energy consumption when train runs between station within the fixed operation time. The decided operation pattern satisfying the minimum energy consumption becomes a target trajectory and a basis for the controller design criteria. To make this goal it grasps the characteristics of urban rail vehicle, realize operation energy model of urban rail vehicle and verify the accuracy of embodied model the Matlab simulation with the same operation result of real route. It searches for operation pattern to minimize operation energy by changing the acceleration and deceleration on the imaginative route and proposes operation pattern minimizing energy consumption by applying real operation data between Dolgogee-Sukgye section of Seoul Metropolitan Subway Line 6.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.3
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• pp.451-458
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• 2022

In Korea, five major ports have been designated as sulfur oxide emission control areas to reduce air pollutant emissions, in accordance with Article 10 of the "Special Act on Port Air Quality" and Article 32 of the "Ship Pollution Prevention Regulations". As regulations against vessel-originated air pollutants (such as PM, CO2, NOx, and SOx) have been strengthened, the Ministry of Oceans and Fisheries(MOF) enacted rules that newly built public ships should adopt eco-friendly propulsion systems. However, particularly in diesel-electric hybrid propulsion systems,the demand for precise control schemes continues to grow as the fuel saving rate significantly varies depending on the control strategy applied. The conventional Power Take In-Power Take Off(PTI - PTO) mode control adopts a rule-based strategy, but this strategy is applied only in the low-load range and PTI mode; thus, an additional method is required to determine the optimal fuel consumption point. The proposed control method is designed to optimize fuel consumption by applying the equivalent consumption minimization strategy(ECMS) to the PTI - PTO mode by considering the characteristics of the specific fuel oil consumption(SFOC) of the engine in a diesel-electric hybrid propulsion system. To apply this method, a specific fishing vessel model operating on the Korean coast was selected to simulate the load operation environment of the ship. In this study, a 10.2% reduction was achieved in the MATLAB/SimDrive and SimElectric simulation by comparing the fuel consumption and CO2 emissions of the ship to which the conventional rule-based strategy was applied and that to which the ECMS was applied.

• The Transactions of the Korean Institute of Power Electronics
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• v.24 no.1
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• pp.40-48
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• 2019

Hybrid electric propulsion systems (H-EPSs) are an intermediate step for integrated full electric propulsion warships. H-EPSs are a dynamic combination of mechanical and electrical propulsion systems to achieve the required mission performances. The system modes could adapt to meet the requirement of the various operation conditions of a warship. This paper presents a configuration and operating modes of H-EPSs considering the operation conditions of a destroyer class warship. The system has three propulsion modes, namely, motoring mode, generating mode [power take off (PTO) mode], and mechanical mode. The PTO mode requires a careful fuel efficiency analysis because the fuel consumption rate of propulsion engines may be low compared with the generator's engines depending on the loading power. Therefore, the calculation of fuel consumption according to the operating modes is performed in this study. Although the economics of the PTO mode depends on system cases, it has an advantage in that it ensures the reliability of electric power in case of blackout or minimum generator operation.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.7
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• pp.42-48
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• 1994

In this paper, a low power and high speed flash Analog-to-Digital Converter using current-mode concept is proposed. Current-mode approach offers a number of advantages over conventional voltage-mode approach, such as lower power consumption small chip area improved accuracy etc. Rescently this concept was applied to algorithmic A/D Converter. But, its conversion speed is limited to medium speed. Consequently this converter is not applicable to the high speed signal processing system. This ADC is fabricated in 1.2um double metal CMOS standard process. This ADC's conversion time is measured to be 7MHz, and power consumption is 2.0mW, and differential nonlinearity is less than 1.14LSB and total harmonic distortion is -50dB. The active area of analog chip is about 350 x 550u$m^2$. The proposed ADC seems suitable for a single chip design of digital signal processing system required high conversion speed, high resolution small chip area and low power consumption.

• The Research Journal of the Costume Culture
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• v.18 no.1
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• pp.177-189
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• 2010

The purpose of this study is to research the conspicuous consumption characteristic expressed in the modern fashion. The conspicuous consumptions are classified with 2 parts as follows as: 1. The motive of conspicuous consumption, 2. The effect of conspicuous consumption. And the motive of conspicuous consumption is 1) conspicuous consumption, 2) conformity consumption, 3) compensatory consumption. The effect of conspicuous consumption is 1) veblen effect, 2) bandwagon effect, 3) snob effect. The veblen effect is caused either by the belief that higher price means higher quality, or by the desire for conspicuous consumption to be seen as buying an expensive, prestige item. The bandwagon effect is people tend to follow the crowd without examining the merits of a particular thing. The snob effect refers to the desire to own unusual, expensive or unique goods. The conspicuous consumption has produced conflicting results of the homogeneous imitation and the different scarcity. Consequently conspicuous consumption characteristic expressed in the modern fashion refers to the conformable imitation and the different scarcity. The conformable imitation is pursuit of first lady look and imitation. The different scarcity refers to the desire to own exclusive or unique goods. The unique value is pursuit of limited edition and art mode.

• Journal of the Semiconductor & Display Technology
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• v.10 no.2
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• pp.13-17
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• 2011

We have developed a new energy-consuming monitoring system that has made it possible to measure the energy consumption of a gas scrubber, one of semiconductor processing equipments, and installed this system to the gas scrubber under operating at a manufacture site. Using this system, we have measured consumptions of electric power and processing gas consumed at standby to operating mode. In case of the gas scrubber, processing gas flows continuously into it at standby and operating mode. Therefore, if the electric power has been supplied, the processing gas can flows into the device for 24 hours. Moreover, at operating of gas scrubber, the amount of electricity consumption is 5 kWh. At Standby of gas scrubber, it spends 3kwh. It is certain that the energy consumption is greater at operating mode than at standby mode. The carbon emission rates from 24 hour gas scrubber operation are 236 $kgCO_2$/day of $N_2$, 57 $kgCO_2$/day of electric power and 0.001 $kgCO_2$/day of cooling water. Most of carbon is emitted from $N_2$ gas and electric power consumption.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.3
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• pp.65-76
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• 2000

To measure the fuel consumption rate of a vehicle, a car is tested on chassis dynamometer following given driving mode. But the fuel consumption rate measured by this method may be somewhat different from that measured in on-road driving conditions. It may be due to not considering road grade in driving modes. In this study, new driving modes which include road grade are proposed, and the simulation program to estimate the real driving fuel consumption rate of a vehicle is developed. On-road car tests to verify the simulation program are carried out and the results of the simulation are analysed and compared with those of the experiments.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.4
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• pp.871-876
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• 2011

In this paper, a voltage-controlled frequency tunable current-mode integrator and a 3rd-order current-mode Chebyshev filter in 1.8V-$0.18{\mu}m$ CMOS is realized for software radio applications in system-on-chips. This filter is used for reconstruction purposes between a current-steering DAC and a current-mode mixer. Power consumption of the designed filter can be reduced by using a current-mode small size integrator. And also, cutoff frequency of this filter is variable between 1.2MHz and 10.1MHz, the power consumption is 2.85mW. And the voltage bias compensated circuit is used to control the voltage variation.in the designed filter.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.10A
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• pp.776-783
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• 2009

Current-cut circuit is an effective method to obtain low power consumption in wireless communication systems as high speed OFDM. For the operation of current-mode FFT LSI with analog signal processing essentially requires current-mode serial-to-parallel/parallel-to-serial converter with multi input and output structure. However, the Hold-mode operation of current-mode serial-to-parallel/parallel-to-serial converter has unnecessary power consumption. We propose a novel current-mode serial-to-parallel/parallel-to-serial converter with current-cut circuit and full chip simulation results agree with experimental data of low power consumption. The proposed current-mode serial-to-parallel/parallel-to-serial converter promise the wide application of the current-mode analog signal processing in the field of low power wireless communication LSI.

• IEMEK Journal of Embedded Systems and Applications
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• v.15 no.5
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• pp.215-225
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• 2020

Light detection and ranging (LiDAR) sensors detect the distance of the surrounding environment and objects. Conventional LiDAR sensors require a certain amount of a power because they detect objects by transmitting lasers at a regular interval depending on a constant resolution. The constant power consumption from operating multiple LiDAR sensors is detrimental to autonomous and electric vehicles using battery power. In this paper, we propose two algorithms that improve the inefficient power consumption during the constant operation of LiDAR sensors. LiDAR sensors with algorithms efficiently reduce the power consumption in two ways: (a) controlling the resolution to vary the laser transmission period (T_P) of a laser diode (LD) depending on the vehicle's speed and (b) reducing the static power consumption using a sleep mode depending on the surrounding environment. A proposed LiDAR sensor with a resolution control algorithm reduces the power consumption of the LD by 6.92% to 32.43% depending on the vehicle's speed, compared to the maximum number of laser transmissions (N_x·max). The sleep mode with a surrounding environment-sensing algorithm reduces the power consumption by 61.09%. The proposed LiDAR sensor has a risk factor for 4-cycles that does not detect objects in the sleep mode, but we consider it to be negligible because it immediately switches to an active mode when a change in surrounding conditions occurs. The proposed LiDAR sensor was tested on a commercial processor chip with the algorithm controlling the resolution according to the vehicle's speed and the surrounding environment.