• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.8
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• pp.1398-1406
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• 2008

This paper describes the electrical breakdown characteristics of broken toughened glass stem insulators by comparing with those of sound ones. The broken toughened glass stem insulators were taken from the electric railway field. According to the international standards, the sound and broken toughened glass stem insulators were tested in electrical strength. In the test, the power frequency voltage and the impulse voltage with a standard waveform were applied to the insulators. The power frequency voltage tests were carried out under both dry and wet condition and the impulse voltage tests under only dry condition. The acquired results were compared one another and discussed in electrical breakdown characteristic by analyzing the flashover progress pictures. As a result, the electrical strength of the broken toughened glass insulators was acquired and the processes of the surface breakdown on the toughened glass insulators were confirmed.

• Journal of the Korean Society of Safety
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• v.26 no.5
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• pp.23-26
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• 2011

The aim of this paper is to evaluate noise characteristics of an electric power driven hammer. These investigation and analysis were made according to the ISO 1680/1 and MIL-STD 7410-1 and lead-wrapping experiment method that was used to identify the principal noise sources and analyze its noise. Hammer generates loud noise and it irritates and affects many people. Repeated exposures to loud noise can lead people to permanent hearing loss. Based on the contribution analysis, we confirm that the striker part is a major noise source and it has directional noise radiation pattern, which is left and right.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1155-1156
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• 2007

This paper deals with dynamic simulation and design characteristic of Linear Switched Reluctance Motor (LSRM). First, we derived design factor from pole arc ratio of stator and mover. Second, we decided design parameter from design factor using time constant. Finally, analyze dynamic characteristics for LSRM using simulation.

• Proceedings of the KIEE Conference
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• 1995.07a
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• pp.291-293
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• 1995

LPM(Linear pulse motor) was developed as a prototype. In this paper, the design results of prototype and its dynamic characteristics are shown. The prototype was designed by using permeance analysis and the thrust value was also confirmed by comparing with the analysis results of the finite element method. To verify the performance of LPM. dynamic characteristics were measured. In slewing characteristic of the LPM, the thrust value of prototype LPM is higher than commercial level. A X-Y table was structured as a application of the prototype LPM. A controller and user's interface was also developed. By using this control system, the position error of X-Y table was checked. The repeat position error in linear movement was under than ${\pm}$ 100 micron.

• Proceedings of the KIEE Conference
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• summer
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• pp.141-143
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• 2004

This paper presents the results of an investigation of the direct short term impacts of electric service interruption incurred by agriculture customers. The study used a direct visit survey to determine the customer assessment of electric service interruption and characteristic. The variation in interruption cost with the characteristics of interruptions such as duration, time of day, frequency, and day of interruption was also investigated.

• Proceedings of the KIEE Conference
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• summer
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• pp.144-146
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• 2004

This paper presents the results of an investigation of the direct short term impacts of electric service interruption incurred by fisheries customers. The study used a direct visit survey to determine the customer assessment of electric service interruption and characteristic. The variation in interruption cost with the characteristics of interruptions such as duration, time of day, frequency, and day of interruption was also investigated.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.17 no.4
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• pp.369-376
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• 1988

Among several methods to solve the unbalanced electric power load, the Ice Storage System (ISS) for the air conditioning is relatively easy to realize and gives big effect on balancing the electric power load. The goals of this study are to develop the practical ISS for the air conditioning through the design, manufacturing and performance test of the experimental ISS (size $0.335m^3$, cold storage capacity 14200 kcal, IPF 0.4). Thermal fluid motion inside the ice storage tank during cooling storage and cooling release are studied. The data are analyzed by the dispersion analysis and optimal design conditions are derived from the result.

• Progress in Superconductivity and Cryogenics
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• v.11 no.2
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• pp.37-40
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• 2009

A mixed working fluid has a potential to widen the operation temperature range of the thermosiphon. In this study, the thermosiphon using $N_2\;and\;CF_4$ mixture as the working fluid is fabricated and tested to verify its transient thermo hydraulic characteristic. A transparent pyrex glass tube was used for the thermosiphon itself and the vacuum chamber was also fabricated by glass to visualize the internal state of thermo siphon. Onset of condensation temperature was related to the partial pressure of $CF_4$. Two solidifications were observed and condensate temperature range of mixed working fluid was from 160K to 70.7K with $N_2$ 25% composition.

• Computers and Concrete
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• v.34 no.3
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• pp.267-277
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• 2024

In this article, the primary resonance characteristic of magneto-electro-elastic plates is analyzed, in which the geometric imperfection, thermal effect and shear deformation are taken into account, Applying Hamilton's principle, derivation of nonlinear motion equations is performed. Through solving these equations according to the modified Lindstedt Poincare method, the impacts of external electric voltage, magnetic potential, boundary conditions, temperature changes, geometric imperfection and aspect ratio on the resonance behaviors of MEE plates are examined. It can be found that, as the electric potential rises, the resonance position will be advanced. As the magnetic potential goes up, the resonance frequency of the plates increases, thus delaying the resonance position. As the initial geometric imperfection rises, the resonance position does not change, and the hard spring properties of the plates gradually weaken.

• KIPS Transactions on Computer and Communication Systems
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• v.5 no.10
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• pp.293-302
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• 2016

Since the electricity is produced and consumed simultaneously, predicting the electric load and securing affordable electric power are necessary for reliable electric power supply. In particular, a university campus is one of the highest power consuming institutions and tends to have a wide variation of electric load depending on time and environment. For these reasons, an accurate electric load forecasting method that can predict power consumption in real-time is required for efficient power supply and management. Even though various influencing factors of power consumption have been discovered for the educational institutions by analyzing power consumption patterns and usage cases, further studies are required for the quantitative prediction of electric load. In this paper, we build an electric load forecasting model by implementing and evaluating various machine learning algorithms. To do that, we consider three building clusters in a campus and collect their power consumption every 15 minutes for more than one year. In the preprocessing, features are represented by considering periodic characteristic of the data and principal component analysis is performed for the features. In order to train the electric load forecasting model, we employ both artificial neural network and support vector machine. We evaluate the prediction performance of each forecasting model by 5-fold cross-validation and compare the prediction result to real electric load.