• The Transactions of the Korean Institute of Electrical Engineers B
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• v.52 no.8
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• pp.405-412
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• 2003

This paper presents a three-phase Line-Interactive uninterruptible power supply (UPS) system with series-parallel active power-line conditioning capabilities, using synchronous reference frame (SRF) based controller, which allows an effective power factor correction, source harmonic voltage compensation, load harmonic current suppression, and output voltage regulation. The three-phase UPS system consists of two active power compensator topologies. One is a series active compensator, which works as a voltage source in phase with the source voltage to have the sinusoidal source current and high power factor under the deviation and distortion of the source voltage. The other is a parallel active compensator which works as a conventional sinusoidal voltage source in phase with the source voltage, providing to the load a regulated and sinusoidal voltage with low THD (total harmonic distortion). The control algorithm using SRF method and the active power flow through the Line-interactive UPS systems are described and studied. The simulation and experimental results are depicted in this paper to show the effect of the proposed algorithm.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.1003-1008
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• 2001

In beamforming method, source positions are predicted by MUSIC (Multiple Signal Classification) power method and composite sound fields can then be decomposed into each partial field by beamforming, detenninistically without restriction of the distance between reference microphones and sources. However, reference microphone array shape is important in both MUSIC and beamforming method. Thus the present paper describes the effect of the reference microphone array shape.

• Nuclear Engineering and Technology
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• v.54 no.5
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• pp.1754-1759
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• 2022

The activity of gamma-ray emitting nuclides is calculated assuming that each gamma-ray is detected individually; thus, the magnitude of the coincidence summing signal must be considered during activity calculations. Here, the correction factor for the coincidence summing effect was calculated, and the detection efficiencies of two HPGe detectors were compared. The CANBERRA Inc. GC4018 high-purity Ge detector provided an estimate for the peak-to-total ratio using a point source to determine the coincidence summing correction factor. The ORTEC Inc. GEM60 high-purity Ge detector uses EFFTRAN in LVis to obtain the parameters of the detector and source model and the gamma-gamma and gamma-X match estimates, in order to determine the coincidence summing correction factor. Nuclide analyses, radioactivity comparisons, and analyses of reference material samples were performed utilizing certified reference materials to accurately determine the detection efficiencies. For both Co-60 and Y-88, the detection efficiency for a point source increased by an average of at least 12-13%, whereas the detection efficiency determined using LVis increased by an average of at least 13-15%. The calculated radioactivity values of the certified reference material and reference material samples were accurate to within 3% and 6% of the measured values, respectively.

• The Journal of the Acoustical Society of Korea
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• v.19 no.3E
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• pp.33-39
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• 2000

This study investigated whether the adjacency principle. demonstrated in a perceived visual space, can be applied to auditory space. In order to demonstrate an auditory adjacency principle, multiple sound sources were varied in direction and distance in an acoustically absorbant space. Specifically, a NEAR sound source was located 10° to the left of the listener's midline at a distance of 2 meters; a FAR sound source was located 10° to the right at a distance of 5 meters. These sources served as perceptual reference points with respect to the localization of three test sounds, all at a distance of 3 meters. Two of three test sounds were directionally closer to the NEAR and FAR reference sounds, respectively. The other was between the reference sources directionally. The listener was asked to judge the perceived distances and the loudness of the three test sounds and the two reference sounds. The results indicated that the apparent distances of the test sounds were most determined by the disparity of distance between each test sound and the reference sound most directionally adjacent to it. Therefore, the findings offer evidence that the adjacency principle can be applied to the auditory space.

• Journal of Magnetics
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• v.16 no.4
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• pp.391-397
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• 2011

An inductance measurement method for interior permanent magnet synchronous machine (IPMSM) is proposed in this paper. In this method, the motor is measured at standstill condition, and only a 3-phase voltage source, an oscilloscope and a DC voltage source are required. Depending on the deductive dq-axis voltage equations in the stationary frame of reference, the dq-axis inductances at different current magnitude and vector angle can be calculated by the measured 3-phase voltages and currents. And hence, the saturation and cross-magnetizing effect of the inductances are measurable. This paper introduces the principle equations, experiment setup, data processing, and results comparison on the concentrated-winding and distributed-winding IPMSMs.

• Journal of Oriental Neuropsychiatry
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• v.23 no.3
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• pp.175-190
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• 2012

Objectives : The purpose of this study is To to study as reference (Ed note: 'study as reference' is awkward and unclear) for practical application in clinics, examine the procedure of historical changes and compare components and their doses of herbal medicines, which are recorded in Chapter Sinmun Jeongan of "Donguibogam". Methods : I examined 23 Herb Medicines in Chapter Sinmun Jeongan of "Donguibogam". Fourteen books, which were noted in Chapter Sinmun Jeongan of "Donguibogam" and 14 books were mentioned in the same part of "Uibujeonrok", which were selected as reference. Results and Conclusions : Fourteen documents were referred to as the 23 Herb Medicines in Chapter Sinmun Jeongan of "Donguibogam". A total of 21 Herb Medicines were recorded in the source book, but 2 Herb Medicines were not recorded. Eleven Herb Medicines among 21 were recorded in the source book, which were directly quoted from the firstly appeared books and 10 Herb Medicines were re-quoted from other books that succeeded the source books. I suspect that the components and dosages of the Herb Medicines were revised, according to the author's clinical experience and circumstances.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.629-631
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• 2015

In this proceedings, preliminary results of the KVN Source-Frequency Phase-Referencing (SFPR) observation of 3C 66A and 3C 66B are presented. The motivation of this work is to measure the core-shift of these 2 sources and study the temporal evolution of the jet opacity. Two more sources were observed as secondary reference calibrators and each source was observed at 22, 43, and 86 GHz simultaneously. Our preliminary results show that after using the observations at the lower frequency to calibrate those at the higher frequency of the same source, the residual visibility phases for each source at the higher frequencies became more aligned, and the coherence time became much longer; also, the residual phases for different sources, within 10 degrees angular separations, follow similar trends. After reference to the nearby calibrator, the SFPRed maps were obtained as well as the astrometric measurements, i.e. the combined coreshift. The measurements were found to be affected by structural blending effects because of the large beamsize of KVN, but this can be corrected with higher resolution maps (e.g. KAVA maps).

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.10
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• pp.4814-4834
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• 2018

This paper presents an architecture for wireless sensor networks (WSNs) with blind source separation (BSS) applied to retrieve the received mixing signals of the sink nodes first. The little-to-no need of prior knowledge about the source signals of the sink nodes in the BSS method is obviously advantageous for WSNs. The optimization problem of the BSS of multiple independent source signals with complex and noncircular distributions from observed sensor nodes is considered and addressed. This paper applies Castella's reference-based scheme to Novey's negentropy-based algorithms, and then proposes a novel fast fixed-point (FastICA) algorithm, defined as the reference-signal negentropy complex FastICA (RSNT-cFastICA) for complex-valued noncircular-distribution source signals. The proposed method for the sink nodes is substantially more efficient than Novey's quasi-Newton algorithm in terms of computational speed under large numbers of samples, can effectively improve the power consumption effeciency of the sink nodes, and is significantly beneficial for WSNs and wireless communication networks (WCNs). The effectiveness and performance of the proposed method are validated and compared with three related BSS algorithms through theoretical analysis and simulations.

• Proceedings of the KIPE Conference
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• 2016.07a
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• pp.359-360
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• 2016

This paper presents a new predictive current control (PCC) method to achieve the coordinate control of power and current of the matrix converter under unbalanced input voltages. In order to control the power fluctuation in the input side, the flexible source current reference is generated based on the positive-negative sequence components of the input voltage. The optimal switching state to adjust source and load currents is selected by minimization the cost function which is obtained from the sum of the absolute errors between the current references and their predictive values. Simulation results are given to validate the effectiveness of the proposed PCC method.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1642-1645
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• 2007

The brightness of LED changes according to the current flowing through LEDs. The current mirror was used to drive LEDs effectively. The reference current of the current mirror was usually controlled by the resistor but the size of this resistor is very large and this resistor consumes too much power for high power LED backlight driving. The reference current of the current mirror LED driver was controlled by using flyback converter at small size with low power consumption in this paper. The concept of active current source was presented.