• Proceedings of the IEEK Conference
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• 2003.07d
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• pp.1379-1382
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• 2003

Recently, mobile embedded systems used widly in various applications. Managing power consumption is becoming a matter of primary concern because those systems use limited power supply. As an approach reduce power consumption, voltage can be scaled down. according to the execution time and deadline. By reducing the supplying voltage to 1/N power consumption can be reduced to 1/N. DPM-S is a well known method for dynamic voltage scaling. In this paper, we enhanced DPM-S by using average execution time aggressively. The frequency of processor is calculated based in average execution time instead of worst case execution time. Simulation results show that our method achieve up to 5％ energy savings than DPM-S.

• IEMEK Journal of Embedded Systems and Applications
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• v.2 no.3
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• pp.164-173
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• 2007

In this paper, we present a time-triggered mechanism for providing energy consumption profiles in the level of C functions. The similar mechanisms have already been introduced at the previous researches such as PowerScope and ePRO. Instead, we, in this paper, introduce our efforts to extend these researches to incorporate power domains and DVS(Dynamic Voltage Scaling), then to provide GUI-based tool as a plug-in to ESTO which is an IDE for Embedded S/W development based on Eclipse. From our experimental results, we could conclude that our approach worked and produced consistent energy consumption profiles on the DVS-applied program codes, and also displayed function level and time domain power consumption information with diverse presentation skills such as tables, phi-chart, bar-chart, 2-D graphs, consequently, is expected to provide more ease-to-use and productive IDE for lower power embedded S/W developers.

• Journal of Platform Technology
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• v.12 no.2
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• pp.34-44
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• 2024

This paper proposes a dynamic clock supply control algorithm and a system load power stabilization algorithm that minimizes the power consumption of the sensing system, which accounts for the largest percentage of power consumption in mobile devices, to extend the usage time of the rechargeable battery mounted on the mobile device. The dynamic clock supply control algorithm can reduce the power consumed by the sensing system by configuring a circuit to cut off the power of the sensing system and by recognizing the state of low sensor change and adjusting the measurement cycle. The system load power stabilization algorithm is an algorithm that controls the power of the surrounding module according to the power consumption state, and when it requires a lot of power, it controls the clock supply to stabilize the operation. The experimental results confirmed that applying only the dynamic clock supply control algorithm reduces the power consumed by the sensing system by 17%, and applying only the system load power stabilization algorithm reduces power consumption by 9.3%, enabling it to operate stably in situations that require a lot of power such as image processing. When both algorithms were applied, the power consumption of the battery was reduced by 67% compared to before applying the algorithm. Through this, the reliability of the proposed method was confirmed.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.10
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• pp.95-104
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• 2004

This paper propose a motion estimator architecture to reduce the power consumption of the most-power-consuming motion estimation method when designing multimedia SoC with deep submicron technologies below 0.13${\mu}{\textrm}{m}$. The proposed architecture considers both dynamic and static power consumption so that it is suitable for large leakage process technologies, while conventional architectures consider only dynamic power consumption. Consequently, it is suitable for mobile information terminals such as mobile videophone where efficient power management is essential. It exploits full search method for simple hardware implementation. It also exploits early break-off method to reduce dynamic power consumption. To reduce static power consumption, megablock shutdown method considering power line noise is also employed. To evaluate the proposed architecture when applied multimedia SoC, system-level control flow and low-power control algorithm are developed and the power consumption was calculated based on thor From the simulation results, power consumption was reduced to about 60%. Considering the line width reduction and increased leakage current due to heat dissipation in chip core, the proposed architecture shows steady power reduction while it goes worse in conventional architectures.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.7
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• pp.935-941
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• 2012

This paper describes a study of conventional electrical rig and simulated application of Flywheel Energy Storage system on the power system of the offshore plants with dynamic positioning system with the following aims: improve fuel consumption on engines, prevent blackout and mitigate voltage sags due to pulsed load and fault. Fuel consumption has been analyzed for the generators of the typical drilling rigs compared with the power plant with Flywheel Storage Unit which has an important aid in avoiding power interruption during DP (Dynamic Positioning) operation. The FES (Fly wheel Energy storage System) releases energy very quickly and efficiently to ensure continuity of the power supply to essential consumers such as auxiliary machinery and thrusters upon main power failure. It will run until the standby diesel generator can start and supply the electric power to the facilities to keep the vessel in correct position under DP operation. The proposed backup method to utilize the quick and large energy storage Flywheel system can be optimized in any power system design on offshore plant.

• Journal of Communications and Networks
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• v.18 no.4
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• pp.551-558
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• 2016

In multifiber all-optical networks, optical amplifiers are used for amplifying multiple optical signals with different wavelengths in fibers. An optical amplifier operates when any of lightpaths passes through it. Therefore, it should simultaneously amplify as many lightpaths as possible for efficiently utilizing its power. This paper proposes a dynamic lightpath establishment scheme considering the use efficiency of the optical amplifiers and the depletion of the wavelength resources in multifiber all-optical networks. The proposed scheme provides a routing and wavelength assignment strategy that reduces both the power consumption of the optical amplifiers and the blocking probability of the lightpath establishment. Through simulation experiments, we demonstrate the effectiveness of the proposed scheme.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.155-158
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• 2005

An invesitigation on power consumption of a mobile multimedia system using OFDM and MDVS technique is reported here. Analysis and simulation are performed to find the significances of proposed Microscopic Dynamic Voltage Scaling(MDVS) tehnique[4] on digital processor in terms of power saving. A study is also made to show power reduction in mobile multimedia system by incorporating OFDM modulation scheme in RF front-end. Finally, overall power consumption by functionally distinguished blocks ie. RF front-end, digital processor and human interface unit is shown here. Total power consumption is 8.2W for 2Mbps SD-quality WCDMA multimedia video service - the power consumption of digital processor is 3.9W(48%), the power consumption of RF front-end is 3.2W (36%), and the power consumption of interface is 1.8W(16%). Power saving of applying purposed MDVS technique is 35% in digital processor, and power saving of OFDM technique is 10-12dB in RF front-end.

• Proceedings of the Korea Contents Association Conference
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• 2007.11a
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• pp.197-200
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• 2007

Dynamic power management reduces the power consumption of the system by switching system components into different power states, which have different power consumption levels. The main function of a power management is to decide when to perform state transitions. In this paper, a power management model based on stochastic processes is introduced. This model is developed using SRN (Stochastic Reward Nets), which has facilities to represent system queue and various modeling functions.

• Journal of the Korean Vacuum Society
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• v.12 no.2
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• pp.93-104
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• 2003

For evaluation of durability of low vacuum pumps, it is required to examine the performance and degradation of low vacuum pumps. Pump degradation may result from abnormalities associated with the performance in many areas of pump operation. The diagnostics method can be used to monitor the pump performance in the semi-conductor process line. Based on the mechanical defect of the pump, the dynamic response and reliability of the system for performance test, and the dynamic characteristics of the pump were experimentally assessed. The theoretical work rate for the compression process in the pump was calculated, and then the efficiency of the pump associated with the power consumption was evaluated. This analysis will be useful in detecting pump degradation with increasing the power consumption. To determine the predominant factors of pump degradation, it is important to evaluate the entire pumping system. We studied vibration, dynamic pressure, pumping speed, and power consumption of low vacuum pumps. Our results can be utilized for the future research on the evaluating technology of durability of low vacuum pumps.

• Nuclear Engineering and Technology
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• v.54 no.8
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• pp.2840-2851
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• 2022

Electric boilers (EBs) are the backup steam source for the auxiliary steam system of high-temperature gas-cooled reactor nuclear power plants. When the plant is in normal operations, the EB is always in hot standby status. However, the current hot standby operation strategy has problems of slow response, high power consumption, and long operation time. To solve these problems, this study focuses on the optimization of hot standby operations for the EB system. First, mathematical models of an electrode immersion EB and its accompanying deaerator were established. Then, a control simulation platform of the EB system was developed in MATLAB/Simulink implementing the established mathematical models and corresponding control systems. Finally, two optimization strategies for the EB hot standby operation were proposed, followed by dynamic simulations of the EB system transient from hot standby to normal operations. The results indicate that the proposed optimization strategies can significantly speed up the transient response of the EB system from hot standby to normal operations and reduce the power consumption in hot standby operations, improving the dynamic performance and economy of the system.