• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 추계종합학술대회 논문집
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• pp.703-706
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• 1998

This paper presents an efficient substrate-bias generator(SBG)for low-power, high-density DRAM's The proposed SBG can supply stable voltage with switching the supply voltage of driving circuit, and it can substitude the small capacitance for the large capacitance. The charge pumping circuit of the SBG suffere no VT loss and is to be applicable to low-voltage DRAM's. Also it can reduce the power consumption to make VBB because of it's high pumping efficiency. Using biasing voltage with positive temperature coefficient, VBB level detecting circuit can detect constant value of VBB against temperature variation. VBB level during VBB maintaining period varies 0.19% and the power dissipation during this period is 0.16mw. Charge pumping circuit can make VBB level up to -1.47V using VCC-1.5V, and do charge pumping operation one and half faster than the conventional ones. The temperature dependency of the VBB level detecting circuit is 0.34%. Therefore the proposed SBG is expected to supply a stable VBB with less power consumption when it is used in low power DRAM's.

• 대한가정학회지
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• 제27권3호
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• pp.133-146
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• 1989

The purpose of this study was to investigate the differences of conjugal power type and conjugal violence level according to social class. This study was also intended to examine the relations between conjugal power type and conjugal violence level. The subjects of this study were 492 high school students in Seoul. Conjugal power was measured with used to measure the conjugal violence level. For the statistical analysis of data, x2-test, Pearson's r, F-test, Duncan's Multiple Range Test and Cronbach's α for reliability were performed. The major results of this study were summarized as follows; 1. There were significant differences according to social class in conjugal power type: The higher social class of the family, the more Syncratic Type were found. And the lower social class of the family, the more Wife Dominant Type were found. 2. There were significant differences according to social class in conjugla violence level: Couples of the lowest class appeared to be more verbal aggression and physical violence. 3. The most severe Husband-to-Wife verbal aggression and physical violence were appeared when the conjugal power type is either Husband Dominant Type or Wife Dominant Type.

• ETRI Journal
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• 제30권1호
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• pp.47-58
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• 2008

In sensor networks, analyzing power consumption before actual deployment is crucial for maximizing service lifetime. This paper proposes an instruction-level power estimator (IPEN) for sensor networks. IPEN is an accurate and fine grain power estimation tool, using an instruction-level simulator. It is independent of the operating system, so many different kinds of sensor node software can be simulated for estimation. We have developed the power model of a Micaz-compatible mote. The power consumption of the ATmega128L microcontroller is modeled with the base energy cost and the instruction overheads. The CC2420 communication component and other peripherals are modeled according to their operation states. The energy consumption estimation module profiles peripheral accesses and function calls while an application is running. IPEN has shown excellent power estimation accuracy, with less than 5% estimation error compared to real sensor network implementation. With IPEN's high precision instruction-level energy prediction, users can accurately estimate a sensor network's energy consumption and achieve fine-grained optimization of their software.

• 전력전자학회논문지
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• 제11권2호
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• pp.120-126
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• 2006

본 논문에서는 Multi-level PDP 구동회로의 Sustain 스위치를 구동하기 위해 Boot-strap chain 방식의 Gate driver를 제안한다. 제안된 Gate driver는 한 개의 High-side N-MOSFETS를 구동하기 위해 별도의 Floating power supply 가 필요치 않고 한 쌍의 다이오드와 캐패시터만을 사용한다. 제안 Gate driver 회로를 적용함으로서, Multi-level PDP driver의 가격과 무게 및 부피를 줄일 수 있다.

• 한국조명전기설비학회지:조명전기설비
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• 제9권5호
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• pp.51-56
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• 1995

The transistors of single phase 3 level PWM Inverter compose output power transistors and neutral point clamping transistors, which are NPN transistors. Waveforms of driving signals for this are PWM waves for power transistors and period operating waves for neutral point clamping transistors, which signals made W-type modulation from rectangular and sine wave. The output power transistors operate at ON-time complementary and neutral point clamping transistors operate at OFF-time complementary respectively. Therefore, each transistors operate in half period at parallel. Characteristics of this inverter circuit is parallel switching method about series switching method of general inverter. As modulation of 3 level drive signals made from full-wave rectifier of sine wave and rectangular wave, which are level wave about 3 level of complementary transistor inverter. So, this circuit composed complementary operation inverter of NPN transistors only compare with PNP-NPN complementary inverter, which have high power 3 level inverter of complementary operation.

• Journal of Power Electronics
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• 제18권2호
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• pp.588-603
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• 2018

This paper presents the idea of a smart load that can adjust the input power flow based on the intermittent power available from RESs (Renewable Energy Resources) to regulate the line voltage, and draw a constant power from the grid. To this effect, an innovative power flow controller is presented based on a Resistive ES (Electric Spring) in combination with a PEAT (Power Electronics based Adjustable Transformer), which can effectively shape the load power flow at the subnetwork level. With a PEAT incorporated in the step down transformer at the grid side, the proposed controller can supply non-critical loads through local RESs, and the critical loads can draw a relatively constant power from the grid. If there is an abundance of power produced by the RESs, the controller can supply both non-critical loads and critical loads through the RES, which significantly reduces the power demand from the grid. The principle, practicality, stability analysis, and controller design are presented. In addition, simulation results show that the power flow controller performs well in shaping the load power flow at the subnetwork level, which decreases the power demand on the grid. Experimental results are also provided to show that the controller can be realized.

• Nuclear Engineering and Technology
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• 제54권10호
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• pp.3878-3887
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• 2022

For the future energy-mix policy for carbon neutrality, demand for the capability of load-follow operation has emerged in nuclear power plants in order to accommodate the intermittency of renewable energy. The short-term decay heat analysis is also required to evaluate the decay heat level varied by the power level change during the load-follow operation, which is a very important parameter in terms of short-term decay heat removal during a grace time. In this study, the short-term decay heat level for 10 days after the shutdown was evaluated for both seasonal and daily load-follow cases. Additionally, the nuclide-wise contribution to the accumulated decay heat for 10 days was analyzed for further understanding of the short-term decay heat behavior. The result showed that in the seasonal case, the decay heat level was mainly determined by the power level right before the shutdown and the amount of each nuclide was varied with the power variation due to the long variation interval of 90 days. Whereas, in the daily case, the decay heat level was strongly impacted by the average power level during operation and meaningful mass variations for those nuclides were not observed due to the short variation interval of 0.5 days.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1989년도 한국자동제어학술회의논문집; Seoul, Korea; 27-28 Oct. 1989
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• pp.553-556
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• 1989

Nowadays in power plant feed water control, it is very important to retain the stable drum level though power changes very fast. For the stable drum level in power plant, we have to model our plants and get the system functions. We make the L.Q. controller by using these functions and apply it to these systems. And we get the more stable drum level which is controlled by feed water qualities.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2003년도 학술발표논문집
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• pp.491-494
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• 2003

An Automatic Water Level Measurement System has been developed in this study. It has the characteristics that it use lower power and solar power and it has the ability of sending data and remote-controlled by wireless MODEM this system was set up in the experimental site and was tested. Also, the management system for the water level data has been developed and will be used by instruments administrating reservoirs.

• Journal of Power Electronics
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• 제17권5호
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• pp.1308-1316
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• 2017

The distributed maximum power point tracking (DMPPT) concept is widely adopted in photovoltaic systems to avoid mismatch loss. However, the high cost and complexity of DMPPT hinder its further promotion in practice. Based on the concept of DMPPT, this paper presents an integrated submodule level half-bridge stack structure along with an optimal current point tracking (OCPT) control algorithm. In this full power processing integrated solution, the number of power switches and passive components is greatly reduced. On the other hand, only one current sensor and its related AD unit are needed to perform the ideal maximum power generation for all of the PV submodules in any irradiance case. The proposal can totally eliminate different small-scaled mismatch effects in real-word condition and the true maximum power point of each PV submodule can be achieved. As a result, the ideal maximum power output of the whole PV system can be achieved. Compared with current solutions, the proposal further develops the integration level of submodule DMPPT solutions with a lower cost and a smaller size. Moreover, the individual MPPT tracking for all of the submodules are guaranteed.