• KIPS Transactions on Computer and Communication Systems
• /
• v.2 no.2
• /
• pp.67-74
• /
• 2013

Approximate string matching problems have been studied in diverse fields. Recently, fast approximate string matching algorithms are being used to reduce the time and costs for the next generation sequencing. To measure the amounts of errors between two strings, we use a distance function such as the edit distance. Given two strings X(|X| = m) and Y(|Y| = n) over an alphabet ${\Sigma}$, the edit distance between X and Y is the minimum number of edit operations to convert X into Y. The edit distance between X and Y can be computed using the well-known dynamic programming technique in O(mn) time and space. The edit distance also can be computed using the Four-Russians' algorithm whose preprocessing step runs in $O((3{\mid}{\Sigma}{\mid})^{2t}t^2)$ time and $O((3{\mid}{\Sigma}{\mid})^{2t}t)$ space and the computation step runs in O(mn/t) time and O(mn) space where t represents the size of the block. In this paper, we present a parallelized version of the computation step of the Four-Russians' algorithm. Our algorithm computes the edit distance between X and Y in O(m+n) time using m/t threads. Then we implemented both the sequential version and our parallelized version of the Four-Russians' algorithm using CUDA to compare the execution times. When t = 1 and t = 2, our algorithm runs about 10 times and 3 times faster than the sequential algorithm, respectively.

• Proceedings of the KIEE Conference
• /
• 1988.07a
• /
• pp.788-791
• /
• 1988

The C-T characteristics of nitridized MOS capacitor have been studied. The generation lifetimes were calculated using C-T transient response ans found to vary as sample condition. This is due to the non-uniformity of fast surface state. Also, This experimental curves were different from theoretical curves. The result suggests that the change in material structure (from SiO2 to Si-N-O) is important in improving minority carrier lifetime.

• Korean Journal of Materials Research
• /
• v.23 no.9
• /
• pp.531-536
• /
• 2013

This paper investigates the effect of prolonged high temperature exposure on concentric laminated $Al_2O_3-ZrO_2$ composites. An ultrafine scale microstructure with a cellular 7 layer concentric lamination with unidirectional alignment was fabricated by a multi-pass extrusion method. Each laminate in the microstructure was $2-3{\mu}m$ thick. An alternate lamina was composed of 75%$Al_2O_3$-(25%m-$ZrO_2$) and t-$ZrO_2$ ceramics. The composite was sintered at $1500^{\circ}C$ and subjected to $1450^{\circ}C$ temperature for 24 hours to 72 hours. We investigated the effect of long time high temperature exposure on the generation of residual stress and grain growth and their effect on the overall stability of the composites. The residual stress development and its subsequent effect on the microstructure with the edge cracking behavior mechanism were investigated. The residual stress in the concentric laminated microstructure causes extensive micro cracks in the t-$ZrO_2$ layer, despite the very thin laminate thickness. The material properties like Vickers hardness and fracture toughness were measured and evaluated along with the microstructure of the composites with prolonged high temperature exposure.

• Korean Journal of Optics and Photonics
• /
• v.12 no.1
• /
• pp.48-54
• /
• 2001

We investigate the generation of the dark spatial soliton and its role of wave guiding in Fe doped$LiNbO_3$ A cw Ar+ laser of 488 nm is used for the generation of the dark spatial soliton. The generation of the dark spatial soliton is observed even at the laser intensity as low as 10 mW/cm2. The self-defocusing effect is observed when the direction of the intensity variation is parallel to the optic axis, while it can't be seen when perpendicular to the axis. So, it is verified that the refractive index change is generated parallel to the optic axis. When 633 nm He-Ne laser beam is injected into the dark spatial soliton, the beam propagates just as in the diffraction free medium. So, it is verified that the dark spatial soliton can act as a waveguide.eguide.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.9 no.2
• /
• pp.93-100
• /
• 2001

To study the possibility of agricultural utilization of seafood processing wastewater sludges, the change of temperature, decreasing ratio of weight generation quantity of $CO_2$ and $NH_3$, and contents of inorganic elements for composting by adding different rates of zeolite and livestock manure to seafood processing wastewater sludges were investigated. Changes of temperature, decreasing ratio of total weight and generation quantity of $CO_2$ were not little different with increasing addition rates of zeolite for composting. But the less addition quantity of livestock manure is, the higher were temperature and decreasing ratio weight for composting. Ceneration quantity of $NH_3$ in composting materials as adding zeolite ti 5, 10 and 20% and livestock manure to 50, 65 and 80% were 68, 61 and $46mg/kgvs{\cdot}hr$, respectively, for composting periods. So, $NH_3$ generated little quantity as much as possible addition of zeolite and manure. Contents of T-C and T-N little decreased and C/N ratio little increased after composting than before. Content of $P_2O_5$, $K_2O$, CaO also increased a little, that of MgO is not different and that of Mn decreased very sharply in all conditions after composting than before.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2010.11a
• /
• pp.141-142
• /
• 2010

• The Journal of Internal Korean Medicine
• /
• v.26 no.1
• /
• pp.107-118
• /
• 2005

Objectives : Peroxynitrite $(ONOO^-)$, fonned from the reaction of $O_2^-$ and NO, is a cytotoxic species that can oxidize several cellular components such as proteins, lipids and DNA. It has been implicated in the aging process and age-related disease such as Alzheimer's disease, rheumatoid arthritis, cancer and atherosclerosis. Due to the lack of endogenous enzymes to thwart $ONOO^-$ activation, developing a specific $ONOO^-$ scavenger is remarkably important. The aim of this study was to investigate scavenging activities of $ONOO^-$ and its precursors, NO and $O_2^-$ and its scavenging mechanism of Ojawhan. Methods : To investigate scavenging activities of $ONOO^-$, NO, $O_2^-$ and its scavenging mechanism using fluorescent probes, DCFDA, DAF-2 and DHR 123. The $ONOO^-$ scavenging activity on Ojawhan was assayed by measuring oxidized dihydrorhodamine 123 (DHR 123) by fluorometry. Oxidative stress was induced by strong oxidants t-butyl hydroperoxide (t-BHP). Endothelial cell (YPEN-1) was used for detection of intracellular oxidative stress. Results : Ojawhan markedly scavenged authentic $ONOO^-$, $O_2^-$ and NO. It also inhibited $ONOO^-$ induced by $O_2^-$ and NO which are derived from SIN-1. Furthennore, ${\underline{Ojawhan}}$ blocked lipopolysaccharide (LPS)-induced $ONOO^-$, $O_2^-$ and NO generation utilizing kidney homogenates of LPS-injected mouse and inhibited t-BHP-induced ROS and $ONOO^-$ in endothelial cell culture system. Conclusions : These results suggest that Ojawhan be developed as an effective $ONOO^-$ scavenger for the prevention of $ONOO^-$ involved diseases and age-related diseases.

• The Korea Journal of Herbology
• /
• v.36 no.5
• /
• pp.93-99
• /
• 2021

Objective : Caryophylli Flos has been used in Korean medicine to relieve vomiting and pains caused by chills that make fluid circulation difficult. This study was designed to investigate the protective effect of ethanol extract of Caryophylli Flos (CF) in hydrogen peroxide (H₂O₂)-induced apoptotic cell death in human keratinocyte HaCaT cells. Methods : CF was prepared by extracting 200 g of Caryophylli Flos in 2 L of ethanol for 48 h. Cell viability was measured by MTT assay, and the protein expression was monitored by Western blot analysis. Apoptosis was determined by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Reactive oxygen species (ROS) was measured using fluorescent dye, and reduced glutathione (GSH) was determined with a colorimetric commercial kit. Results : CF protected HaCaT cells from cell death caused by oxidative stress after H₂O₂ treatment. H₂O₂ amplified generation of ROS and induced depletion of GSH, whereas these changes in ROS and GSH were inhibited by GF treatment. In addition, H₂O₂ resulted in apoptosis as assessed by TUNEL assay and the expression of apoptosis regulator proteins. However, cells treated with CF showed a decrease in TUNEL-positive cells and restored the reduced expression of procaspase-9, -3 and PARP. Conclusion : This study showed cytoprotective effects of CF by anti-apoptotic activity while exerting antioxidative activity in H₂O₂-treated HaCaT cells. These results suggest that CF could be beneficial in skin damage caused by oxidative stress.

• Journal of the Korean Ceramic Society
• /
• v.54 no.2
• /
• pp.150-157
• /
• 2017

Three types of piezoelectric single crystals [PMN-PT (Generation I $[Pb(Mg_{1/3}Nb_{2/3})O_3-PbTiO_3]$), PMN-PZT (Generation II $[Pb(Mg_{1/3}Nb_{2/3})O_3-Pb(Zr,Ti)O_3]$), PMN-PZT-Mn (Generation III)] were grown by the solid-state single crystal growth (SSCG) method, and their dielectric and piezoelectric properties were measured and compared. Compared to (001) PMN-PT and PMN-PZT single crystals, the (001) PMN-PZT-Mn single crystals exhibited a higher transition temperature between the rhombohedral and tetragonal phases ($T_{RT}=144^{\circ}C$), as well as a higher coercive electric field ($E_C=6.3kV/cm$) and internal bias field ($E_I=1.6kV/cm$). The (011) PMN-PZT-Mn single crystals showed the highest coercive electric field ($E_C=7.0kV/cm$), and the highest stability of $E_C$ and $E_I$ during 60 cycles of polarization measurement. These results demonstrate that both Mn doping (for higher electromechanical quality factor ($Q_m$)) and a (011) crystallographic orientation (for higher coercive electric field and stability) are necessary for high power transducer applications of these piezoelectric single crystals. Specifically, the (011) PMN-PZT-Mn single crystal (Gen. III) had the highest potential for application in the fields of SONAR transducers, high intensity focused ultrasound (HIFU), ultrasonic motors, and others.

• Journal of Acupuncture Research
• /
• v.20 no.4
• /
• pp.209-219
• /
• 2003

This study was performed to determine if Juglandis semen extract(JSE) has free radical scavenging and antioxidant activities. Superoxide anion generation by xanthine oxidase/xanthine and in neutrophils activated by phorbol-12, 13-dibutyrate was inhibited by JSE and its effect was dose-dependent. JSE also inhibited generation of $H_2O_2$ induced by glucose oxidase/glucose and in opossum kidney cells treated with antimycin A. JSE exerted a direct $H_2O_2$ scavenging effect. Exposure of opossum kidney cells to 1mM tBHP caused a significant increase in lipid peroxidation, which was prevented by JSE. JSE also prevented tBHP-induced LDH release. These data suggest that JSE has free radical scavenging and antioxidant activities. However, further studies should be carried out to find the active ingredient(s) of JSE that exerts radical scavenging action.