• Journal of Life Science
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• v.19 no.8
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• pp.1009-1015
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• 2009

The beneficial use of sedatives is often required for medically ill patients. This study examined the effect of plant flavonoids and diazepam peripheral-type benzodiazepine receptor (PBR) activation and glucose utilization in breast cancer cells, along with their interactions. In estrogen receptor negative MDA-MB-231 cells, the anti-proliferative activity of fisetin (3,7,3',4'-tetrahydroxyflavone) and diazepam was more prominent than in estrogen receptor positive MCF-7 cells. Unlike PBR ligands, treatment with $10^{-6}$ M concentration of diazepam for 3 days exhibited anti-proliferative effects, while similar to apigenin (4',5,7-Trihydroxyflavone) and fisetin, diazepam hardly affected the PBR mRNA expression by MDA-MB-231 cells. Treatment with $10^{-6}$ M concentration of flavonoids and diazepam for 3 days inhibited the glucose utilization of MDA-MB-231 cells. Treatment with $10^{-6}$ M concentration of flavonoids and diazepam for 6 days showed increased cytotoxicity and reduced the PBR mRNA expression of the MDA-MB-231 cells. Apigenin enhanced diazepam-induced anti-proliferative effects on the MDA-MB-231 cells as well. All together, this study showed the in vitro anti-proliferative activity of flavonoids and diazepam on MDA-MB-231 breast cancer cells, plus additive enhancements. In conclusion, this study provides experimental basis for advanced trials in the future.

• Knowledge Management Research
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• v.22 no.2
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• pp.247-268
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• 2021

Investors mainly use PER and PBR among financial ratios for valuation and investment decision-making. I conduct an analysis of two basic financial ratios from a statistical perspective. Financial ratios contain key accounting numbers which reflect firm fundamentals and are useful for valuation or risk analysis such as enterprise credit evaluation and default prediction. The distribution of financial data tends to be extremely heavy-tailed, and PER and PBR show exceedingly high level of kurtosis and their extreme cases often contain significant information on financial risk. In this respect, Extreme Value Theory is required to fit its right tail more precisely. I introduce not only GPD but exGPD. GPD is conventionally preferred model in Extreme Value Theory and exGPD is log-transformed distribution of GPD. exGPD has recently proposed as an alternative of GPD(Lee and Kim, 2019). First, I conduct a simulation for comparing performances of the two distributions using the goodness of fit measures and the estimation of 90-99% percentiles. I also conduct an empirical analysis of Information Technology firms in Korea. Finally, exGPD shows better performance especially for PBR, suggesting that exGPD could be an alternative for GPD for the analysis of financial ratios.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.1
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• pp.48-56
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• 2018

Due to the growing concerns of energy resource depletion and environmental destruction, the mass production of microalgae has been studied. The scale-up of a photobioreactor (PBR) is required for the mass production of biomass. In this paper, the geometric parameters and oxygen transfer rate (OTR) are considered, to scale up a flat panel photobioreactor (FP PBR). The PBR is designed using the goal-driven optimization (GDO) method to accomplish the scale-up. The local sensitivity of each output parameter with respect to the input parameter is analyzed through the design of experiment (DOE), and the design candidates are evaluated with the screening sampling method. The volumetric mass transfer coefficient is measured by the dynamic method.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.2
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• pp.154-163
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• 2013

Adhesive bonding and plastic welding have been widely used to join two plastic materials together. The goal of this paper is to determine a proper joining technology of a pair of flat panel (FP) photobioreactor (PBR) case. The material of the FP PBR case is polycarbonate (PC) plate. Two types of adhesion, including acryl adhesive and two-part epoxy adhesive, as well as two types of plastic welding technology, including ultrasonic welding and thermal welding, are employed for joining of PC plates. In order to influence of the adhesion and welding conditions on the joining characteristics of the PC plates in operational conditions of the FP PBR case, the morphology in the vicinity of the joined region as well as the water and pressure resistance characteristic are investigated. In addition, the variation of the bonding strength of the joined region and deformation behaviors in the vicinity of the joined region according to the adhesion and welding conditions is examined via the lap-shear test. From the results of basic experiments, proper joining technologies are chosen. Using the chosen joining technologies, the FP PBR case are fabricated to perform full-scale durability experiment. The results of the full-scale durability experiment have been shown that the chosen joining technologies can be applicable to fabricate the FP PBR case.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.26-26
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• 2017

Seed germination stimulated by light is said to be photoblastism. Photoblastism has not been reported in cereal crops, especially in the rice, but Korean weedy rice was reported to have photoblastism and longer mesocotyl than cultivar. Photoblastic weedy rice (PBR) was used to identify QTLs for photoblastism and mesocotyl length. In previous works, QTLs for photoblastism, pbr1 and pbr12 were identified on chromosomes 1 and 12 using 124 F4 lines from a cross between Ilpum and PBR using bulked segregant analysis. Two QTLs for mesocotyl elongation, qMel-1 and qMel-3 were mapped on chromosomes 1 and 3 120 F8 lines from the same cross. Of interest, the RM8260-RM246 region of pbr1 overlapped with a region of qMel-1. To know whether these two QTLs are functionally related, 110 F3 lines were developed from a cross between Ilpum and CR7124. CR7124 having photoblastism and long mesocotyl was selected from 120 F8 lines. 95 F3 lines were measured for germination rate in a light and dark condition and mesocotyl length. Mesocotyl length and germination rate in the dark condition in F3 lines showed significant correlation (r = 0.7, P < 0.0001). 95 $F_3$ lines were genotyped with RM7419 on chromosome 1. ANOVA showed that RM7419 was tightly linked to QTLs for photoblastism as well as mesocotyl length on chromosome 1 (P < 0.0001) indicating the tight linkage of two QTLs. Fine mapping of the two QTL is underway to analyze their functional relationship.

• Bulletin of the Korean Chemical Society
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• v.15 no.1
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• pp.25-28
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• 1994

Weakly electron withdrawing bromine substituted poly(2-bromo-1,4-phenylenevinylene) (PBrPV) was synthesized th-rough water-soluble precursor method. The linear and nonlinear optical properties of PBrPV were compared with those of poly(1,4-phenylenevinylene) (PPV). The third-order nonlinear optical susceptibility, X^{(3)}$, was measured by using third-harmonic generation (THG) technique at 1907 nm, fundamental wavelength. The calculated $X^{(3)}$ values of PPV and PBrPV were 3${\times}$ 10$^{-12}$ esu and 2${\times}$10$^{-12}$ esu, respectively.

• Proceedings of the Optical Society of Korea Conference
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• 1989.02a
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• pp.13-19
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• 1989

Passive mode-locking of a pulsed Nd:YAG laser is achieved with saturable absorbers, BDN dye in iodoethane solvent and Kodak Eastman # 26 dye in 1,2-dichloroethane solvent, and its optimum conditions are investigated. The thickness of saturable absorbers employed in the laser mode-locking is 0.16~0.50mm. The PBR (peak-to-background ratio) measured in the oscilloscope is 79.8% in Kodak Eastman # 26 dye at the neighbourhood of the peak power, whereas the passive mode-locking with BDN dye gives PBR of 67.7%. BDN and Kodak Eastman # 26 dyes are superior in photostability over Kodak eastman # 9860 and # 9740 dyes which were used previously in passive mode-locking. From the PBR curve, we find that Kodak Eastman # 26dye is more effective than BDN dye in passive mode-locking. The spacing between the adjacent pulses of the pulse train, which depends on the laser cavity length, is measured and is found to be 7 nsec for the cavity length of 100cm.

• ETRI Journal
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• v.38 no.2
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• pp.302-313
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• 2016

Use of a passive bistatic radar (PBR) system in the surveillance or monitoring of an area has its advantages. For example, a PBR system is able to utilize any available signal of opportunity (for example, broadcasting, communication, or radio navigation signals) for the purposes of surveillance. With this in mind, there are potentially many research areas to be explored; in particular, the capability of signals from existing and future communication systems, such as 4G and 5G. Long-Term Evolution (LTE) is the world's most current communication system. Given this fact, this paper presents the latest feasibility studies and experimental results from using LTE signals in PBR applications. Details are provided about aspects such as signal characteristics, experimental configurations, and SNR studies. Six experimental scenarios are carried out to investigate the detection performance of our proposed system on ground-moving targets. The ability to detect is demonstrated through use of the cross-ambiguity function. The detection results suggest that LTE signals are suitable as a source signal for PBR.

• Korean Journal of Food Science and Technology
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• v.29 no.5
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• pp.969-973
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• 1997

In order to produce transglucosylated steviosides continuously, some types of bioreactors were investigated with cyclodextrin glucanotransferase immobilized on a high porous anion exchange resin, Diaion HPA75. Among the bioreactors, the packed-bed reactor (PBR) showed the highest specific productivity. The effect of linear velocity in a PBR on the stevioside conversion was not significant in the range of $10{\sim}60\;cm/hr$ at the same space velocity of $1.2\;hr^(-1)$. When the space velocity of bioreactor was varied from 0.2 to $1.1\;hr^{-1}$, the optimal velocity of substrate solution was determined as $0.7\;hr^(-1)$. The stevioside conversion of more than 70% was maintained during 20 days in the continuous operation, if about 20% of immobilized enzyme was replaced in the top of reactor after two weeks operation as the one of the control methods in bioreactor. The specific production, which refers to as the amount of commercially valuable transglucosylated steviosides produced by a unit amount of immobilized cyclodextrin glucanotransferase, was found to be ca. 150g product/g immobilized enzyme.

• Journal of Korean Society of Forest Science
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• v.102 no.2
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• pp.300-304
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• 2013

Pine wilt disease caused by pine wood nematode, Bursaphelenchus xylophilus (Steiner et Buhrer) Nickle, has become the most serious threat to pine trees in Korea since 1988. Pine wood nematode is transferred to healthy trees by Monochamus alternatus (Coleoptera: Cerambycidae) during its maturation feeding and female oviposition. A typical control method against insect vectors in Korea is fumigation of the dead trees by using metam-sodium SL (25%). However, this method is not environment friendly because of the forest contamination by chemical application and destroying landscape by plastic cover. Portable Bark Remover (PBR) was invented to reduce these environmental problems. The vectors oviposit under the bark of the newly dead trees only. Debarking infested trees prevents the vectors from laying eggs and eventually, they can not complete their life cycle. The PBR is a modified debarking device that is attached on the top of the electrical chain saw, which allows ease and rapid debarking of the infested trees. The new method by PBR is expected to be more economic and effective than other conventional methods such as "crushing", "burning" and "fumigation".