• The Transactions of the Korean Institute of Electrical Engineers A
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• v.50 no.12
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• pp.584-590
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• 2001

This paper presents a windows program package for solving security constrained OPF in interconnected Power systems, which is based on the combined application of evolutionary programming(EP) and sequential quadratic programming(SQP). The objective functions are the minimization of generation fuel costs and system power losses. The control variables are the active power of the generating units, the voltage magnitude of the generator, transformer tap settings and SYC setting. The state variables are the bus voltage magnitude, the reactive power of the generating unit, line flows and the tie line flow In OPF considering security, the outages are selected by contingency ranking method. The resulting optimal operating point has to be feasible after outages such as any single line outage(respect of voltage magnitude, reactive power generation and power flow limits). The OPF package proposed is applied to IEEE 14 buses and 10 machines 39 buses model system.

• Journal of Power Electronics
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• v.11 no.3
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• pp.271-278
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• 2011

This paper presents a LLC resonant controller IC for secondary side control without external active devices to achieve low profile and low cost LED back light units. A gate driving transformer is adopted to isolate the primary side and the secondary side instead of an opto-coupler. A new integrated dimming circuitry is proposed to improve the dynamic current control characteristic and the current density of a LED for the brightness modulation of a large screen LCD. A dual-slope clock generator is proposed to overcome the frequency error due to the under shoot in conventional approaches. This chip is fabricated using 0.35 ${\mu}m$ BCD technology and the die size is $2{\times}2\;mm^2$. The frequency range of the clock generator is from 50 kHz to 500 kHz and the range of the dead time is from 50 ns to 2.2 ${\mu}s$. The efficiency of the LED driving circuit is 97 % and the current consumption is 40 mA for a 100 kHz operation frequency from a 15 V supply voltage.

• The Korean Journal of Food And Nutrition
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• v.27 no.1
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• pp.89-98
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• 2014

In this study, soybean is used to produce soymilk according to various extracting methods and heating time. Specifically, the soy slurry is being filtered before being heated, or heated before being filtered. Following that the soymilk produced is freeze-dried to be powdered, and then, the quality characteristics of the powdered soymilk are mutually compared to determine the applicability of various food additives. The freeze-dried soymilk powder shows 2.03~6.35% of moisture content, and in terms of unit quantity, retained more proteins, which suggests that the ratio of protein extraction is higher than any other nutrients. Accordingly, the protein coefficient is significantly higher in soymilk powder being heated and processed than in raw soybeans. In particular, protein coefficient is the highest in the soymilk which is heated for 20 minutes before being filtered (SHBF20). The longer the heating time was, the trypsin inhibitor (TI) tended to be far less active. Such an inactivation seems to be more apparent in the "SHAF" soymilk powder than "SHBF" soymilk powder. Because protein had to be denaturated by heating for soymilk, the nitrogen solubility index (NSI) of soymilk powder is decreased considerably, while the protein digestibility, water absorption, emulsification and foaming activity all increase. Oil absorption tends to decrease slightly. As discussed above, the soymilk heated for 10 minutes after being filtered (SHAF10) and the soymilk heated for 20 minutes before being filtered (SHBF20) show optimum processing conditions for soymilk powder.

• Journal of Korean language education
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• v.28 no.4
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• pp.297-335
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• 2017

Recently, Chinese universities have been putting their priority on cultivating industry-academia linked talents, catching up with social change and industrial demand. Accordingly, vocational purpose education is being emphasized even in Korean language education. When facing active trade between Korea and China, the importance of business Korean language education will be magnified, and therefore, the demand for business Korean textbooks will grow accordingly. To strengthen the basis for the development of future business Korean textbooks, this study conducted a general analysis of a business Korean textbook for Chinese learners. Specifically, the textbook was examined by largely dividing it into external and internal structures. After dividing the internal structure into "purpose of compilation", "composition of the textbook", "learning contents", and "learning activity", the composition of the textbook was once again divided into "overall composition" and "unit composition", and the learning contents was further divided into "subject", "language content", and "supplementary knowledge." Furthermore, an analysis was conducted. The status and directions for future development of business Korean textbooks for Chinese learners are delineated and suggestions for improvement are provided. This study has its significant in that a general analysis was conducted on a business Korean textbook for Chinese learners, and is expected to be used as basic research material for the future development of business Korean textbooks.

• Journal of the Korea Safety Management & Science
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• v.2 no.2
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• pp.95-108
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• 2000

Electrochemical charateristics of activated carbon fiber cloth(ACFC) electrode were studied with propylene carbonate(PC), ${\gamma}$-butyrolactone(GBL) and N,N-dimethyl-formamide(DMF) as a solvent and tetraethylammoniumtetrafluoroborate(TEABF$_4$), tetraethylammoniumhexafluorophosphate(TEABF$_{6}$), tetrabutylammoniumtetrafluoroborate(TBABF$_4$) and tetrabutylammonium hexafluorophosphate(TBAPF$_6$) as an electrolytes(active material). The concentrations of electrolytes were in the range of 0.2~1.2 N, the volume ratios of PC and DMF as a mixed solvent system, were 90：10, 80：20, 70：30, 60：40, 50：50, and 40：60 vol%. Electrochemical characteristics such as electric conductivity, internal resistance, and electric capacitance of fabricated unit cells were measured after the moisture of activated material was removed with molecular sieve. Electrochemical characteristics were better in mixed solvents system than in mono solvent system. The mono solvent system of 1.0 N electrolyte of GBL/TEABF$_4$ with activated carbon cloth electrodes showed better result but the mixed solvent system with PC and DMF/TEABF$_4$(50：50 vol%) and the concentration of 1.0 N electrolyte showed the best characteristics. Internal resistance was 3.47 $\Omega$ and specific capacitance was 19.1 F/g respectively.y.

• Journal of Integrative Natural Science
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• v.6 no.4
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• pp.197-204
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• 2013

The crystal structure of the potential active 4,6-dimethyl-9-phenyl-8,12-dioxa-4,6-diazatetracyclo [8.8.0.02,7.013,18] octadeca-2(7),13,15,17-tetraene-3,5,11-trione 2-ethoxyphenyl (2E)-but-2-enoate ($C_{22}H_{18}N_2O_5$) has been determined from single crystal X-ray diffraction data. In the title compound crystallizes in the monoclinic space group $P_12_1/c_1$ with unit cell dimension a=15.2039(8), b=12.3888(6) and c= 9.8162(5) [alpha & $gamma=90^{\circ}$ beta=98.113(2)]. In the structure fused pyrone and pyran rings each adopt a sofa/envelop conformation. The crystal structure is stabilized by intramolecular C-H... O hydrogen bond interaction.

• Journal of Soil and Groundwater Environment
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• v.19 no.6
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• pp.1-5
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• 2014

The following research was initiated in order to compare the relationship between the amount of gunfire shot and its resulting heavy metal pollution rate. The research was conducted at two firing ranges located inside a military unit stationed in the rear strategical area, where one full distance firing range is used by soldiers in active service, and the other is used by recruits and reserves. The heavy metal pollution rate was measured also on water sample collected from the target zone while raining. Based on values such as the real amount of gunshot fired, amount of heavy metal in the soil of the target zone, and the degree of heavy metal pollution for each firing range, the research showed that although pollution rate was higher when more gunshots were fired, there was no close correlation between the two. The water samples showed that this might result from the soils containing heavy metals eroded and transported by rain due to the target zone having no vegetation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.8
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• pp.3821-3841
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• 2019

Cloud radio access networks (C-RANs) have been regarded in recent times as a promising concept in future 5G technologies where all DSP processors are moved into a central base band unit (BBU) pool in the cloud, and distributed remote radio heads (RRHs) compress and forward received radio signals from mobile users to the BBUs through radio links. In such dynamic environment, automatic decision-making approaches, such as artificial intelligence based deep reinforcement learning (DRL), become imperative in designing new solutions. In this paper, we propose a generic framework of autonomous cell activation and customized physical resource allocation schemes for energy consumption and QoS optimization in wireless networks. We formulate the problem as fractional power control with bandwidth adaptation and full power control and bandwidth allocation models and set up a Q-learning model to satisfy the QoS requirements of users and to achieve low energy consumption with the minimum number of active RRHs under varying traffic demand and network densities. Extensive simulations are conducted to show the effectiveness of our proposed solution compared to existing schemes.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.32 no.3
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• pp.256-261
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• 2019

The use of military lithium batteries in this field accelerates the generation of internal pressure because the active materials, lithium and the electrolyte, react to form sulfur dioxide gas. This also reduces the amount of electrolyte. In this condition, batteries can 'vent' or 'explode' especially when completely discharged. Such venting and explosion can be regarded as a safety accident, as toxic gases and shrapnel are ejected from the batteries which can harm the user. A DTaQ was carried out in 2017 as a quality problem solution project to solve this safety issue. A protection circuit was thereby developed, which included a micro controller unit (MCU) which can stop battery usage when in an over-discharging state by sensing its low-voltage condition. In 2018, this concept was expanded to lithium batteries for the remote controlled ammunition system. This paper reports results of the improved performance.

• Journal of Pharmacopuncture
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• v.22 no.2
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• pp.55-67
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• 2019

The incidences of cancer are continuously increasing worldwide, affecting life of millions of people. Several factors associated with the internal and external environment are responsible for this deadly disease. The key internal determinants like abnormal hormonal regulation, genetic mutations and external determinants such as lifestyle and occupational factors enhances onset of cancer. From the ancient time, plants were remained as the most trusted source of medicine for the treatment of diverse disease conditions. Extensive studies have been performed for the discovery of effective anticancer agent from the plant and still it is going on. Pentacyclic triterpenoids are biologically active phytochemicals having a different range of activities such as anti-inflammatory, hepatoprotective, anti-hypertensive, antiulcerogenic and anti-tumor. These compounds generally contain ursane, oleanane, lupane and friedelane as a chief skeleton of pentacyclic triterpenoids which are generally present in higher plants. Isoprene unit, phytochemical, with good antitumor/anticancer activity is required for the biosynthesis of pentacyclic triterpenoids. Mechanisms such as cytotoxicity, DNA polymerase inhibition, regulation of apoptosis, change in signal transductions, interfere with angiogenesis and dedifferentiation, antiproliferative activity and metastasis inhibition are might be responsible for their anticancer effect. Present review spotlights diverse targets, mechanisms and pathways of pentacyclic triterpenoids responsible for anticancer effect.