• Biomolecules & Therapeutics
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• v.16 no.3
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• pp.293-298
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• 2008

Cirsium japonicum water extracts has been used to treat vascular related diseases. We have previously reported that Cirsium japonicum extracts activated estrogen receptors. It is widely known that estrogen increases the high density lipoprotein cholesterol and decrease the low density lipoprotein cholesterol on the lipid profile. But effects of Cirsium japonicum on lipid profile are not reported yet. Therefore, we have studied the effects of Cirsium japonicum on the lipid content in ovariectomized rats. Thirty Sprague-Dawley (SD) rats of $210{\pm}20\;g$ were studied for 10 weeks. The rats were divided into five groups; (I) sham, no ovariectomized rats plus olive oil, (II) ovariectomized rats plus olive oil, (III) ovariectomized rats plus 0.5 mg/kg $17{\beta}$-estradiol (E2) in olive oil, (IV) ovariectomized rats plus 0.5 mg/kg Cirsium japonicum in olive oil, and (V) ovariectomized rats plus 5 mg/kg Cirsium japonicum in olive oil. Treatment with Cirsium japonicum or E2 induced significant reduction in total cholesterol, low density lipoprotein cholesterol/total cholesterol, total cholesterol/high density lipoprotein cholesterol and low density lipoprotein cholesterol/high density lipoprotein cholesterol compared to control group as well as increase in uterine weight. However, changes in triglycerides levels were different. Our results suggest that Cirsium japonicum is functionally similar to E2 in vivo as well as in vitro.

• International Journal of Precision Engineering and Manufacturing
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• v.2 no.1
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• pp.18-25
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• 2001

Electrolytic polishing is the anodic dissolution process in the transpassive state. It removes non-metallic inclusion and improves mechanical and corrosion resistance of stainless steel. If there is a Bailby layer, it will be removed and the true structure of the surface will be restored. Electrolytic polishing is normally used to remove a very thin layer of material from the surface of metal object. A new electrolyte composed of phosphoric, sulfuric and distilled water has been developed in this study. Two current density, high & low current density regions, have been applied in this study. In this study, In the region of high current density, there is no plateau region but excellent electrolytic polishing effect can be accomplished in short machining time because material removel process and leveling process occur simultaneously. In the low current density region, there can be found plateau region. The material removal process and leveling process occur successively. The aim of this work is to determine electrolytic polishing for stainless steel in terms of high & low current density and workpiece surface roughness.

• Proceedings of the KIEE Conference
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• 1999.11d
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• pp.879-881
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• 1999

Radical and ion densities in a CF4 plasma have been calculated as a function of input power density. 9as pressure and feed gas flow rate using simple 0 dimensional global model. Fluorine atom is found to be the most abundant neutral particle. Highly fragmented species such as CF and CF+ become dominant neutral and ionic radical at the high power condition. As the pressure increases. ion density increases but ionization rate decreases due to the decrease in electron temperature. The fractional dissociation of CF4 feed gas decreases with pressure after increasing at the low pressure range. Electron density and temperature are almost independent of flow rate within calculation conditions studied. The fractional dissociation of CF4 monotonically decreases with flow rate. which results in increase in CF3 and decrease in CF density. The calculation results show that the SiO2 etch selectivity improvement correlates to the increase in the relative density of fluorocarbon ion and neutral radicals which has high C/F ratio.

• Journal of Korean Society of Water and Wastewater
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• v.30 no.5
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• pp.553-559
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• 2016

There has been increasing global interest in the environmental pollution problems produced by fossil fuel consumption and greenhouse gas emissions. In order to tackle these issues, new renewable energy such as solar, wind, bio gas, fuel cell and pressure retarded osmosis(PRO) have been developed extensively. Among these energy sources, PRO is one of the salinity gradient power generation methods. In PRO, energy is obtained by the osmotic pressure generated from the concentration difference between high and low concentration solutions separated by a semipermeable membrane. The development for high power density PRO membranes is imperative with the purpose of commercialization. This study investigates development of thin film composite PRO membrane and spiral wound module for high power density. Also, the influence of membrane backing layer on power density was identified, and the characteristic factors of PRO membranes was determined. Different backing layers were used to improve power density. As expected, the PRO membrane with more porous backing layer showed higher power density.

• Phonetics and Speech Sciences
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• v.3 no.1
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• pp.51-65
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• 2011

This study attempts to investigate the interlanguage speech intelligibility benefit for listeners (ISIB-L), examining Chinese talkers' production of English liquids and its perception of native listeners and non-native Chinese and Korean listeners. An Accent Judgment Task was conducted to measure non-native talkers' and listeners' phonological proficiency, and two levels of proficiency groups (high and low) participated in the experiment. The English liquids /l/ and /r/ produced by Chinese talkers were considered in terms of positions (syllable initial and final), contexts (segment, word and sentence) and lexical density (minimal vs. nonminimal pair) to see if these factors play a role in ISIIB-L. Results showed that both matched and mismatched interlanguage speech intelligibility benefit for listeners occurred except for the initial /l/. Non-native Chinese and Korean listeners, though only with high proficiency, were more accurate at identifying initial /r/, final /l/ and final /r/, but initial /l/ was significantly more intelligible to native listeners than non-native listeners. There was evidence of contextual and lexical density effects on ISIB-L. No ISIB-L was demonstrated in sentence context, but both matched and mismatched ISIB-L was observed in word context; this finding held true for only high proficiency listeners. Listeners recognized the targets better in the non-minimal pair (sparse density) environment than the minimal pair (higher density) environment. These findings suggest that ISIB-L for English liquids is influenced by talkers' and listeners' proficiency, syllable position in association with L1 and L2 phonological structure, context, and word neighborhood density.

• Korean Journal of Remote Sensing
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• v.23 no.3
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• pp.153-160
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• 2007

Forest cover density studies using high resolution satellite data and object oriented classification are limited in India. This article focuses on the potential use of QuickBird satellite data and object oriented classification in forest density mapping. In this study, the high-resolution satellite data was classified based on NDVI/pixel based and object oriented classification methods and results were compared. The QuickBird satellite data was found to be suitable in forest density mapping. Object oriented classification was superior than the NDVI/pixel based classification. The Object oriented classification method classified all the density classes of forest (dense, open, degraded and bare soil) with higher producer and user accuracies and with more kappa statistics value compared to pixel based method. The overall classification accuracy and Kappa statistics values of the object oriented classification were 83.33% and 0.77 respectively, which were higher than the pixel based classification (68%, 0.56 respectively). According to the Z statistics, the results of these two classifications were significantly different at 95% confidence level.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.19 no.2
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• pp.95-102
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• 2013

Exfoliated graphite (EFG) with high aspect ratio was incorporated with high density polyethylene (HDPE) for use as high barrier packaging material such as water-sensitivity electric product and pharmaceutical packaging. Also HDPE/EFG nanocomposite films were prepared by adding the compatibilizer for effective dispersion and compatibility. Their chemical properties, crystal structure properties, thermal properties and water barrier properties of as-prepared HDPE/EFG nanocomposite films were investigated as a function of EFG contents. It showed that there is a weak interfacial interaction between HDPE and EFG, however, the water vapor permeations were decreased from 127 to 78 (70 ${\mu}m{\cdot}g/m^2$, $day{\cdot}atm$) by addition of EFG. Especially, the physical properties of HDPE/EFG nanocomposite films were effectively increased up to 0.5 wt%, however, there were no significant improvement of properties in nanocomposite films at the additional EFG loading. To maximize their performance of the nanocomposite films, further research is required to enhance the dispersion of EFG and compatibility of EFG in HDPE matrix.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.77-77
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• 2011

These days, a growing demand for memory device is filled up with the flash memory and the dynamic random access memory (DRAM). Although DRAM is a reasonable solution for current demand, the universal novel memory with high density, high speed and nonvolatility, needs to be developed. Among various new memories, the magnetic random access memory (MRAM) device is considered as one of good candidate memories because of excellent features including high density, high speed, low operating power and nonvolatility. The etching of MTJ stack which is composed of magnetic materials and insulator such as MgO is one of the vital process for MRAM. Recently, MgO has attracted great interest in the MTJ stack as tunneling barrier layer for its high tunneling magnetoresistance values. For the successful realization of high density MRAM, the etching process of MgO thin films should be investigated. Until now, there were some works devoted to the investigations on etch characteristics of MgO thin films. Initially, ion milling was applied to the etching of MgO thin films. However, ion milling has many disadvantages such as sidewall redeposition and etching damage. High density plasma etching containing the magnetically enhanced reactive ion etching and high density reactive ion etching have been employed for the improvement of etching process. In this work, inductively coupled plasma reactive ion etching (ICPRIE) system was adopted for the improvement of etching process using MgO thin films and etching gas mixes of $CH_4$/Ar and $CH_4$/$O_2$/Ar have been employed. The etch rates are measured by a surface profilometer and etch profiles are observed using field emission scanning emission microscopy (FESEM). The effects of gas concentration and etch parameters such as coil rf power, dc-bias voltage to substrate, and gas pressure on etch characteristics will be systematically explored.

• Proceedings of the KIPE Conference
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• 2017.11a
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• pp.181-182
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• 2017

In the battery system, an isolated converter is used for the stability of the system when controlling the charge and discharge of the battery. A fixed frequency LLC converter which is a type of isolated converter, has the advantage of high efficiency and power density with zero voltage switching at high frequency. Therefore, in this paper, the operation analysis, design and experimental verification of the LLC resonant converter with high efficiency and high power density for the ESS system were conducted.

• Journal of KSNVE
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• v.10 no.4
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• pp.584-595
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• 2000

We design a new actuator for high density optical device in order to control the radial tilting motion. The newly designed actuator makes it possible to control the tilting motion actively, while the coventional actuator compress tilting motion with passive spring. First of all, We present 3-dimensional modeling of actuator and accomplish the modal analysis and magnetic analysis of actuator. Due to these results, a new designed actuator has performance of high sensitivity and high second resonance frequency. Secondly, We present the 3-DOF dynamic modeling of the 4-wire spring type actuator. sensitivity analysis is performed to consider the assembling error, such as the difference of mass center and force center. From these results, the sensitivities of rotation due to the assembly error are revealed and design criteria of rotation is presented. And experimental results of a newly designed actuator are presented and compared with theoretical results. Finally, We propose a dynamic tilt compensation and high acceleration actuator for high density optical storage devices.