• Journal of Electrical Engineering and Technology
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• v.12 no.2
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• pp.643-653
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• 2017

The paper presents controller optimization algorithm for a 12-pulse voltage source converter (VSC) based high voltage direct current (HVDC) system. To get an optimum algorithm, three methods namely conventional-Zeigler-Nichols, linear-golden section search (GSS) and stochastic-particle swarm optimization (PSO) are applied to control of 12 pulse VSC based HVDC system and simulation results are presented to show the best among the three. The performance results are obtained under various dynamic conditions such as load perturbation, non-linear load condition, and voltage sag, tapped load fault at points-of-common coupling (PCC) and single-line-to ground (SLG) fault at input AC mains. The conventional GSS and PSO algorithm are modified to enhance their performances under dynamic conditions. The results of this study show that modified particle swarm optimization provides the best results in terms of quick response to the dynamic conditions as compared to other optimization methods.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.2B no.4
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• pp.191-200
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• 2002

When power consumption increases, power supply must be efficient and reliable for good power quality. The studies on compensation system of power quality are processing actively. Voltage sag among of factors for power quality is generally PI dual control that voltage sag compensation is used. But this control is no more available since of 120[KHz] ripple rejection. So we proposed the control algorithm using PID control in 3-phase unbalanced power system and the series voltage compensator, when voltage sag occurs.

• Food Science and Preservation
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• v.1 no.1
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• pp.37-43
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• 1994

A microcomputer system consisting of 16-bit microcomputer, PCL-711S interface board, censors, and converters have been set up in order to automatically measure temperature, humidity and weight loss which are major variables of storage of apple. This system was operated by PC-LabDAS software. It has been possible to measure continuously the weight loss of Fuji apple stored in CA with the weight converter made by a miniature load cell and a strain amplifier. The temperature was checked by a k-type thermocouple and Pt 100 $\Omega$ RTD, and humidity by PQ653JAl humidity sensor. It has been possible to set up a linear equation which showers high correlationship between the estimate of temperature, weight humidity and the output of the converter in that r2 is more than 0.99. Transpiration rate, a significant factor of quality deterioration for CA storage of apple, can be estimated with these values.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.7
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• pp.1192-1200
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• 2004

Gamma irradiations at 5 or 10 kGy were applied to salted and fermented anchovy sauce, for improving the hygiene Quality and evaluating the genotoxicological safety. In vitro genotoxicological safety of irradiated sauces was evaluated by Salmonella Typhimurium (TA98, TA100, TAI535 and TAI537) and E. coli WP2 uvrA, reversion assay, SOS chromotest (Escherichia coli PQ37), and chromosome aberration test (Chinese hamster lung fibroblast cells) in the absence or presence of an exogenous metabolizing system (S9 mix). The gamma-irradiated samples were not significantly different from nonirradiated-control for three in vitro tests (p＜0.05). ：In vivo micronucleus test using ICR mice (male) was not significantly different from the control at p＜0.05. The salted and fermented anchovy sauce exposed to 5 or 10 kGy-gamma ray revealed negative results in these three in vitro mutagenetic tests and in vivo micronucleus test upto 50,000 $\mu$g/plate, respectively. The results indicated that 5 or 10 kGy gamma-irradiated salted and fermented anchovy sauces did not show any mutagenicity.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.1005-1010
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• 2007

According to revision of Construction Technology Management Act (2005), the government ordering construction which cost is more than 10billion won should investigate the value engineering(VE) of a construction. In this sense, the government actively promote plans in 2008 after identifying the examining standards of the investigation on the VE(2007). It is substantial issue to introduce Pre-Qualification(PQ) in oder to restrain unlicensed VE consulting companies or VE consultants. This system will contribute to the quality and the settlement of the value engineering in our country. The reason why the Korea VE Society founded in 2006 is one of the afore-mentioned reasons. Therefore, we try to establish the value engineering of Build-Transfer-Lease Scheme by providing the practical application of construction value engineering and definite procedures through the example of Andong Culture and Art Center's research in one of the various construction fields.

• Journal of Life Science
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• v.5 no.3
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• pp.121-125
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• 1995

To determine whether the omega 3 family, linolenic acis(LnA) is effective to inhibit carcinogens/mutagens-induced mutagenesis, we employed the Ames test using Salmonella typhimurium strain of TA100 and the SOS chromotest using Escherichia coli PQ37 strain. The inhibitory effect of LnA shown in the Ames assaying system was 95%, 78% and 73% when the mutagenicities were mediated by AFB$_{1}$, MNNG and 4-NQO, respectively. LnA shows a strong antimutagenic activity against indirect mutagen of AFB$_{1}$, whereas the same concentration of LnA exhibited weaker inhibitory effects on the direct mutagen of MNNG and 4-NQO than that of AFB$_{1}$. However. LnA reduced more than 80% of SOS responses induced by MNNG and 4-NQO when the adding concentration increased to 5%. We conclude that LnA contains in vitro antimutagenic properties and that this finding warrants further investigation both in vitro and in vivo to assess its possible chemotherapeutic potential.

• Journal of Electrical Engineering and Technology
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• v.10 no.6
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• pp.2442-2447
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• 2015

Because an electric railway vehicle is a large scale moving load, it can cause various kinds of power quality problems in the railroad power system. The power quality impacts are considered as the strong instantaneous stresses to the related power systems and can cause an accelerating aging and a malfunction of the power supplying components. Therefore, it is necessary to detect the small and intermittent symptoms mixed in the voltage waveform. However, they cannot be detected by the triggering functions of the existing power analyzers installed in the railway systems. This paper will examine the drawback of some fast detection tools and propose an advanced detecting and analyzing method based on a combined TEO and STFT algorithm.

• Proceedings of the KIEE Conference
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• 1989.07a
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• pp.184-188
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• 1989

This paper presents a fast realistic method based on a P-Q decoupled linearized model for contingency analysis. This method involves new idea to correct the errors caused by neglecting the resistance of transmission lines and/or by linearizing the model. The idea is to use fast correction method of errors by the principle of superposition for compensating these errors. Results demonstrating the effectiveness of the method on 25-bus model system and IEEE30-model system are presented

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.192-194
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• 2005

Development of nonlinear loads and compensation instruments make PQ(Power Quality) problem into important issue. Few studies by signal processing and pattern classification as NN(Neural Network), Wavelet Transform, and Fuzzy present feature extraction. A lot of Input features make not always good result and they are difficult to make realtime system. Thus, The dimentionality reduction is indispensable process. PCA(Principal Component Analysis) reduces high-dimensional input features onto a lower-dimensional subspace effectively. It will be useful to apply to realtime system and NN.

• Korean Journal of Heritage: History & Science
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• v.51 no.2
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• pp.124-137
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• 2018

Although the evaluation system for excavation reports has been in operation for over 10 years, there has been no research on the evaluation system. First, this study examined the changes of the evaluation system, and secondly, it analyzed the evaluation factors affecting the evaluation results. As a result of institutional analysis, the present evaluation result is being utilized in PQ, and it is suggested that the evaluation subject institution is limited to the excavation institution, which may cause disadvantages to the participating museums. We also pointed out that a small number of jury members are currently evaluating the report and therefore need to reinforce it to ease the burden of assessment. As a result of evaluation factor analysis, it was confirmed that the target score was lower but the actual effect score was higher. In addition, it suggested that the indicators should be improved because the report system, headings, natural archaeological environment, scope and method of survey, and editing and printing indicators are less influential than other indicators. In addition, we conducted a regression analysis of each group by examining the appropriateness of classification amounts according to current excavation costs. As a result of the analysis, the cost of excavation in the second and third groups in 2015 and 2016 was found to affect the score. This emphasized the need for an in-depth approach to estimating the taxonomic value of the group, which is inconsistent with the initial objective of not affecting the assessment results according to excavation costs.