• Journal of applied mathematics & informatics
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• v.42 no.1
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• pp.123-137
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• 2024

In this paper, Power fuzzy graphs is newly introduced by allotting fuzzy values on power graphs in such a way that the newly added edges, has the edge membership values between a closed interval which depends on vertex membership values and the length of the added edges. Power fuzzy subgraphs and total power fuzzy graphs are newly defined with properties and some special cases. It is observed that every power fuzzy graph is a fuzzy graph but the converse need not be true. Edges that are incident to vertices with the least vertex membership values are retained in the least power fuzzy subgraph. Further, the application of these concepts in real life time has been presented and discussed using power fuzzy graph model.

• JSTS:Journal of Semiconductor Technology and Science
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• v.8 no.2
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• pp.139-142
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• 2008

An X-band MMIC power amplifier for radar application is developed using $0.25-{\mu}m$ gate length GaAs pHEMT technology. A bus-bar power combiner at output stage is used to minimize the combiner size and to simplify bias network. The fabricated power amplifier shows 38.75 dBm (7.5 Watt) Psat at 10 GHz. The chip size is $3.5\;mm{\times}3.9\;mm$.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.3
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• pp.38-44
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• 2009

This paper presents a new windows application based on 3-D graphics and Text-To-Speech (TTS) for effective management of substation equipment. When problems in a power system occur, inexperienced power system operators may have difficulty in understanding the situation as well as finding suitable countermeasures quickly. This paper addresses an effective scheme to visualizing power system equipment under normal and abnormal conditions using 3-D graphics and animations. In addition, the state variations and the order of maintenance priority of substation equipment are represented by TTS and intuitive methods. The proposed system can help power system operators to more quickly understand the state of power system equipment, and it can provide operators with the suitable countermeasures for minimizing damage caused by equipment problems.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.10
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• pp.1515-1521
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• 2013

In this paper, we develop the power management application of the Android operating system that works with a intelligent concent having the functions to protect resistive leakage current, over-current and standby power. Using this power management application a user monitors electrical fire, shock from a concent due to leakage current, can control home appliances by controlling the power supplied to the concents and can easily protect wasted standby powers, anytime and anywhere.

• Current Optics and Photonics
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• v.5 no.2
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• pp.186-190
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• 2021

In this study, a compact, picosecond, mid-infrared 3.8 ㎛ MgO:PPLN optical parametric oscillator (OPO) laser output with high peak power is realized using a master oscillator power amplifier (MOPA) 1 ㎛ solid-state laser seeded by a picosecond fiber laser as the pump source. The pump source was a 50 MHz and 10 ps fiber seed source. After AOM pulse selection and two-stage solid-state amplification, a 1,064 nm laser output with a repetition frequency of 1-2 MHz, pulse width of 9.5 ps, and a maximum average power of 20 W was achieved. Furthermore, a compact short cavity with a unsynchronized pump is adopted through the design of an OPO cavity structure. When the injection pump power was 15 W and the repetition frequency was 1 MHz, the average output power of idler light was 1.19 W, and the corresponding peak power was 119 kW. The optical conversion efficiency was 7.93%. When the repetition frequency was increased to 2 MHz, the average output power of idler light was 1.63 W, the corresponding peak power was 81.5 kW, and the optical conversion efficiency was 10.87%. At the same time, the output wavelength was measured at 3,806 nm, and the beam quality was MX2 = 3.21 and MY2 = 3.34.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.2
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• pp.444-461
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• 2016

A power-saving mechanism for smartphone devices is developed by analyzing the features of data that are received from Internet of Things (IoT) sensors devices to optimize the data processing policies. In the proposed GreenIoT architecture for power-saving in IoT, the power saving and feedback mechanism are implemented in the IoT middleware. When the GreenIoT application in the power-saving IoT architecture is launched, IoT devices collect the sensor data and send them to the middleware. After the scanning module in the IoT middleware has received the data, the data are analyzed by a feature evaluation module and a threshold analysis module. Based on the analytical results, the policy decision module processes the data in the device or in the cloud computing environment. The feedback mechanism then records the power consumed and, based on the history of these records, dynamically adjusts the threshold value to increase accuracy. Two smart living applications, a biomedical application and a smart building application, are proposed. Comparisons of data processed in the cloud computing environment show that the power-saving mechanism with IoT architecture reduces the power consumed by these applications by 24% and 9.2%.

• Journal of the Ergonomics Society of Korea
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• v.33 no.1
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• pp.49-58
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• 2014

Objective: The aim of this study is to enhance the efficiency of education and training through application and management of 'Transfer of Training' in nuclear power plants. Background: Despite the sophistication and standardization of job-related skills and techniques of workers, accidents/incidents keep taking place due to human errors and unsafe actions and behaviors, which translates into the necessity to review and examine the effectiveness and influence of education and training on the workers of nuclear power plants. Method/Results: This study drew the factors of 'Transfer of Training' through a review on the preceding studies and document research. In addition, through expert examination, this study explored the expected effects and possibility of application when managing the influencing factors of 'Transfer of Training' in nuclear power plants. And lastly, management priority order for nuclear power plants was drawn through an AHP analysis. Conclusion: Among the 'Transfer of Training' factors, the training design factor was the most important. In addition, the design of the training and transfer and goal setting showed a high degree of importance among the influencing factors. Application: The management of 'Transfer of Training' in nuclear power plants enhances the capability of workers and improves the operational integrity of nuclear power plants.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.4B no.4
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• pp.170-179
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• 2004

The paper presents technical issues which integrated sensors must address to be implemented in the next generation of power electronics and motor drives. The underlying goal of the sensor integration will be to improve reliability of power conversion systems while making the power converter and motor drive become the primary source of diagnostic signals for the application. The paper focuses on design methodologies that will allow this integration to succeed in meeting the technical demands for both reliability and for application level diagnostics.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.864-866
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• 2002

Power steering of a car is used to reduce driver's handle control power. It is usually operated by oil pressure of engine power. However, electrically power steering (EPS) is used recently instead of oil pressure type for environmental and economical reason. This paper presents structure design and characteristics analysis of SRM for EPS application.

• Proceedings of the KIPE Conference
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• 2004.07b
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• pp.501-505
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• 2004

The study on the hybrid power source for the IMT2000 application has been presented. The hybrid power source is composed of solar cell, super-capacitor and battery. To compensate for the pulse loader of the IMT2000 application, the super-capacitor is connected through the Lithium-ion battery to absorb the pulse current. The solar cell provides the additional current to compensate for the depleted current. The controller design for the hybrid source has been presented and verified through experiment.