• Journal of Electrical Engineering and Technology
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• v.9 no.6
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• pp.2224-2236
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• 2014

The performance of an isolated high voltage full bridge converter is improved using a voltage doubler. In a conventional high voltage full bridge converter, the diode of the transformer secondary voltage undergoes a voltage spike due to the leakage inductance of the transformer and the resonance occurring with the parasitic capacitance of the diode. In addition, in the phase shift control, conduction loss largely increases from the freewheeling mode because of the circulating current. The efficiency of the converter is thus reduced. However, in the proposed converter, the high voltage dual converter consists of a voltage doubler because the circulating current of the converter is reduced to increase efficiency. On the other hand, in the proposed converter, an input current is distributed when using parallel input / serial output and the output voltage can be doubled. However, the voltages in the 2 serial DC links might be unbalanced due to line impedance, passive and active components impedance, and sensor error. Considering these problems, DC injection is performed due to the complementary operations of half bridge inverters as well as the disadvantage of the unbalance in the DC link. Therefore, the serial output of the converter needs to control the balance of the algorithm. In this paper, the performance of the conventional converter is improved and a balance control algorithm is proposed for the proposed converter. Also, the system of the 1.5[kW] PCS is verified through an experiment examining the operation and stability.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.5
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• pp.979-984
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• 2009

In this paper, the technique for production and encoding of new dot-type print watermark is proposed. The print watermark has characteristics similar to those of the digital watermark and function as link which change various first informations(texts, symbols, figures, etc) on the printed matter to secondary contents (sound, video, character, etc) corresponding each to informations on the printed matter. The proposed dot-type print watermark pattern is represented as $16{\times}16$ matrix in $0.4mm^2$ area and dots are printed on only 23 elements of $16{\times}16$ matrix. The size of each dot is so small(0.02mm)that it can not be seen. Because position of printed dots correspond to the position of each digit in binary notation in this paper, they are encoded easily and there are about 8,000,000 watermark patterns enough to express first information of printed matters. It was showed that the proposed print watermark patterns are recognized without difficulty by the own recognition device.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.224-224
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• 2017

In plants, cysteine(Cys) is decisive for protein and glutathione that acts as an indispensable sulfur grantor for methionine and many other sulfur containing secondary products. Cys formation is involved in the consecutive two reactions using two enzymes-serine acetyl transferase (SAT) and O-acetylserine (thiol)lyase (OASTL) and appeared in plant cytosol, chloroplast and mitochondria. OASTL is able to produce mimosine with 3-hydroxy-4-pyridone (3H4P) in lieu of $H_2S$ for Cys. In this report, we describe the first time cloning, purification and characterization of cytosolic(cy)OASTL from M. pudica and its expression in Escherichia coli and try to find out the cross link between this OASTL and the mimosine formation and to elucidate the metabolic role of cy-OASTL in M. pudica. The purified recombinant protein was 34.7 KDa. The optimum reaction pH and temperature was 6.5 and $50^{\circ}C$, respectively. The Michaelis constant (Km) and the Vmax value of the enzyme was $252{\pm}25{\mu}M$ and $57{\pm}3{\mu}M\;cysteine\;min^{-1}\;{\mu}g\;protein^{-1}$ for sulfide and $159{\pm}21{\mu}M$ and $58{\pm}2.4{\mu}M\;cysteine\;min^{-1}\;{\mu}g\;protein^{-1}$ for OAS subsequently. After cleaving the His-tag, we tried to observe cy-OASTL to form mimosine with appropriate substrate but it was not successful. It may be concluded that cy-OASTL of the present study is only Cys specific, not mimosine.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.2
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• pp.133-139
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• 2017

Flight control computer of tiltrotor UAV was designed by redundancy system with primary and secondary channels to improve reliability. The redundancy functions consist of channel switching and data recovery. The channel switching function consists of software method by using cross channel data link and hardware method by using watchdog timer. The data recovery is the function to maintain flight condition when the flight control computer is restarted exceptionally in operation. The redundancy system was verified by flight control computer bench test, system integration test and HILS test. This paper describes the redundancy function of tiltrotor UAV flight control computer and test-verification method.

• Journal of Korean Society of Rural Planning
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• v.21 no.1
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• pp.117-127
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• 2015

This study evaluated properties and items for selecting on a forest healing village. In order to assign a weight value-between factors, this study was conducted the primary survey first and then the secondary survey for measuring the importance of items. Experts'surveys were conducted on 3 items on level 1, 9 items on level 2, 35 items on level 3 with use of AHP technique. In level 1, the main analysis result was that physical resource properties(0.387) indicated the highest importance. in level 2, healing resources of physical properties(0.402), community participation of human resource properties(0.425), and business competency in part of vision(-.438) showed the highest importance. The analysis result of 35 items on level 3 was that in physical resources properties, securing public land in the village(0.220), possessing recreation space(0.440) and resources available for link with healing(0.413) showed the highest importance. In part of human resources properties, the average age of residents(0.465), commitment to the promotion of the villagers(0.367) and support of local leaders(0.318) showed the highest importance. Adequacy of development plan(0.274), forest work experience-related(0.293), and building profit sharing system(0.282) were also evaluated to have a relatively high importance.

• Journal of Integrative Natural Science
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• v.13 no.1
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• pp.27-33
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• 2020

The unsustainable human activities like increased use of automobiles, heavy industrialization and the use of large volumes of fertilizers, chemicals and pesticides in the agricultural land cause climate change problems in one way or another. Under normal circumstances, the heat radiations from the sun will be reflected back. An excessive volume of GHGs in the atmosphere would prevent these radiations from reflecting back. East Asia is facing severe climate change issues in recent times. A lot of climate change problems such as hurricanes and floods have been reported from this region in the last couple of decades. The study aimed at investigating the climate change in East Asia with changing Sea Surface Temperature (SST). The study adopted a quantitative research method with a case study research design where a deliberate focus was made on the East Asia Region. Secondary data was gathered and analyzed to yield both descriptive and inferential statistics. The study concluded that the impact of East Asia Climate variability was significant mainly for some extreme events. Also, the study concluded that there was a significant link between the change of the East Asia climate variability and that of the sea surface temperature. Further, the study concluded that a linear relationship existed between the sea surface temperature and the climate of East Asia. Hence, a linear regression was a significant predictor of the East Asia Climate (EAC) based on changing sea surface temperature. The model revealed that 37.4% of the variations in the climate change index were explained by the changes in the sea surface temperature. The climate was expected to change with a value of 49.48 for a unit change in the sea surface temperature.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.2
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• pp.208-216
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• 2014

Ground station in lunar mission is responsible to receive telemetry signal including sensor data from lunar orbiter and/or lander. At preliminary stage of developing this ground station, receiving performance such as antenna size and noise temperature should be designed on the basis of link budget analysis. When the antenna of ground station is pointing to the moon to communicate with lunar orbiter and/or lander, noise level is supposed to be increasing due to the lunar flux density. It means that the moon is working as a noise source to degrade receiving performance when antenna is pointing to the moon. Antenna noise temperature contributed by the moon was firstly calculated and secondary validated by using test configuration in this paper. Consequently, it was shown that antenna noise temperature caused by the moon was quietly matched with measured one and G/T degradation of receiving system in lunar mission can be calculated depending on antenna size and frequency.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.9A
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• pp.853-866
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• 2008

In this paper, a multi-hop relaying transmission scheme is analyzed regarding its feasibility and potentiality in the IEEE 802.22-based cognitive radio (CR) environment. Shortly, basic design issues are addressed such as relay station (RS) deployment and a frame structure of physical channel to escape inter-hop interference. This paper mainly develops a radio resource management scheme based on spectrum sensing results aggregated from CR secondary nodes and improves the opportunistic spectrum sharing efficiency. In particular, a decision rule about a channel availability is made using a distributed sensing method. Subsequently, spectrum allocation and routing path decision procedures are proposed to establish a link from source to destination with a hop-by-hop manner. Simulation results show that the proposed multi-hop relaying scheme is substantially profitable in CR environments if the number of hops and RS deployment are designed in such a way that the spectrum sharing gain is larger than spectrum division loss which is inherently induced in multi-hop relaying systems.

• The Journal of Korean Physical Therapy
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• v.15 no.1
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• pp.155-170
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• 2003

Lumbar segmental instability is considered to represent a significant sub-group within the chronic low back pain population. This condition has a unique clinical presentation that displays its symptoms and movement dysfunction within the neutral zone of the motion segment. The loosening of the motion segment secondary to injury and associated dysfunction of the local muscle system renders it biomechanically vulnerable in the neutral zone. There in evidence of muscle dysfunction related to the control of the movement system. There is a clear link between reduced proprioceptive input, altered slow motor unit recruitment and the development of chronic pain states. Dysfunction in the global and local muscle systems in presented to support the development of a system of classification of muscle function and development of dysfunction related to musculoskeletal pain. The global muscles control range of movement and alignment, and evidence of dysfunction is presented in terms of imbalance in recruitment and length between the global stability muscles and the global mobility muscles. The local stability muscles demonstrate evidence of failure of aeequate segmental control in terms of allowing excessive uncontrolled translation or specific loss of cross-sectional area at the site of pathology Motor recruitment deficits present as altered timing and patterns of recruitment. The evidence of local and global dysfunction allows the development of an integrated model of movement dysfunction. The clinical diagnosis of this chronic low back pain condition is based on the report of pain and the observation of movement dysfunction within the neutral zone and the associated finding of excessive intervertebral motion at the symptomatic level. Four different clinical patterns are described based on the directional nature of the injury and the manifestation of the patient's symptoms and motor dysfunction. A specific stabilizing exercise intervention based on a motor learning model in proposed and evidence for the efficacy of the approach provided.

• Archives of Pharmacal Research
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• v.24 no.6
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• pp.607-612
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• 2001

Endogenous carbon monoxide (CO) shares with nitric oxide (NO) a role as a putative neural messenger in the brain. Both gases are believed to modulate CNS function via an increase in cytoplasmic cGMP concentrations secondary to the activation of soluble guanylate cyclase (sGC). Recently CO and NO were proposed as a possible mediator of febrile response in hypothalamus. NO has been reported to activate both the constitutive and inducible isoform of the cyclooxygenase (COX). Thus, we investigated whether CO arising from heme catabolism by heme oxygenate (HO) is involved in the febrile response via the activation of COX in the hypothalamus. $PGE_2$ which is a final mediator of febrile response released from primary cultured hypothalamic cells was taken as a marker of COX activity. $PGE_2$ concentration was measured with EIA kits. Exogenous CO (CO-saturated medium) and hemin (a substrate and potent inducer of HO) evoked an increase in $PGE_2$ release from hypothalamic cells, and these effects were blocked by methylene blue (an inhibitor of sGC). And membrane permeable cGMP analogue, dibutyryl-cGMP elicited significant increases in $PGE_2$release. These results suggest that there may be a functional link between HO and COX enzymatic activities. The gaseous product of hemin through the HO pathway, CO, might play a role through the modulation of the COX activity in the hypothalamus.