• Journal of the Korean Chemical Society
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• v.43 no.2
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• pp.28-231
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• 1999

• Proceedings of the KIEE Conference
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• 2001.05a
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• pp.217-219
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• 2001

This paper presents new diagnosis technique for detecting a partial discharge(PD) using antenna. The wavelet transform is applied for the analysis of PD pulse signal because it is difficult to identify PD signal using electromagnetic waves detected by antenna. The capabilities of the proposed diagnosis methodology for detecting PD signal is verified on experiment in laboratory.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.936-940
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• 2007

This paper is about the study on the verification method for railway system SIL which is frequency of hazard, composing Risk, one of the measurement standards for railway system safety. Frequency of hazard can be identified by using FMECA, or HAZOP, and the assessment of identified dangerous failure rate should be done by systematic methods such as FTA. Therefore, this paper provides the hazard identification level for SIL verification and the requirements necessary to verify the integrity of analysis activity.

• Proceedings of the KAIS Fall Conference
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• 2011.05a
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• pp.259-262
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• 2011

MANET 환경에서 노드들이 DNS 서비스를 이용하기 위하여 DNS 서버의 기능을 하는 노드를 선정한다. 하지만 선정된 노드는 많은 자원을 소비하게 된다. 따라서 본 논문에서는 DNS 노드의 분산 선정 및 노드 관리를 2단계 노드체인 형성 과정을 통해 DNS 서비스를 제공하는 시스템을 제안한다.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.2010-2011
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• 2007

Rogowski Coil Current Transformer using PCB(Printed Circuit Board) is produced to analyze characteristics of digital C.T(Current Transformer). Conclusively, this paper expresses a difference and a good point of C.T using PCB.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.11a
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• pp.613-614
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• 2009

최근 네트워크의 가용성을 침해하는 DDoS공격으로 국내외 주요 사이트가 마비되는 사건이 있었다. 본 논문에서는 TCP와 UDP의 자기유사성을 이용하여 유효 대역폭을 측정하고 네트워크의 가용성을 보장하기 위한 한계 대응 시점을 예측하였다. 그리고 실험을 통해 한계 대응 시점의 예측이 정확함을 확인 할 수 있었다.

• Clinical and Experimental Reproductive Medicine
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• v.27 no.4
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• pp.339-344
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• 2000

Objective: To evaluate silane-coated silica particles (Sil-select) as an alternative to polyvinylpyrrolidone-coated particles (Percoll) for gradient separation of spermatozoa, for use in assisted reproduction. Methods: 20 normal semen based on WHO criteria were included in this study. Recovery of motile and morphologically normal spermatozoa after using two-layer Percoll and Sil-select gradient respectively was recorded. Motility, HOST (hypoosmotic swelling test) and the detection of malondialdehyde for LPO (lipid peroxidation) after 24 h of incubation at $37^{\circ}C$ in a 5% $CO_2$ incubator were compared. Results: Percoll (78.5%) and Sil-select (79.1%) showed a significant increase in the motility compared to ejaculate (60.9%) but no difference between Percoll and Sil-select. Normal sperm morphology significantly increased after Percoll (57.6%) and Sil-select (53.7%) compared to ejaculate (35.8%) but no difference between Percoll and Sil-select. No differences in the recovery of motile spermatozoa and motility, HOST and the production of malondialdehyde after 24 h incubation were found when comparing the use of Percoll and Sil-select. Conclusion: Sil-select seems to be an attractive alternative to Percoll for sperm separation in assisted reproduction.

• Clinical and Experimental Reproductive Medicine
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• v.26 no.2
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• pp.257-263
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• 1999

It is well known that discard of seminal plasma from the semen and separation of motile sperm should be preceded before insemination for IUI or IVF. Till now, more than ten kinds of semen treatment methods have been developed. Of those, swim-up and Percoll methods have been used widely in ART laboratories as a routine semen treatment methods because of its advantages. However, there are reports that Percoll can make a genetic trouble because of its chemical structure and therefore the necessity has been arisen to substitute Percoll for other equivalent materials. This study was performed to evaluate the effects of three different sperm preparation methods (swim-up, Percoll and Sil-Select) on sperm motility, sperm recovery rate and fertilization rate. Also, the feasibility of using Sil-Select instead of Percoll in ART was evaluated. Each semen samples were divided into three fractions and motile sperm were recovered by swim-up, Percoll and Sil-Select gradient centrifugation methods. Normal and sub-normal criteria of fifteen semen samples and seventeen IVF cycles were included in these study. As results, no significant difference was found in sperm recovery rate in normal semen treated by a Swim-up, Percoll and Sil-Select method ($13.2{\times}10^6,\;17.5{\times}10^6\;and\;17.7{\times}10^6$ respectively). The initial sperm motility was 61.9% and this increased to 87.1%, 92.6% and 89.5% through Swim-up, Percoll and Sil-Select treatment, respectively. Higher motility was observed in Percoll and Sil-Select treated groups (81.5%, 79.2%, respectively) than swim-up group (66.8%) after incubation for 24hrs. In sub-normal group, sperm recovery rates were higher in Sil-Select group $(2.9{\times}10^6)$ than Percoll gradients group $(1.8{\times}10^6)$. In IVF cycles, the outcomes of fertilization using sperm treated by swim-up and Sil-Select group were similar (82.2%, 79.7% respectively). In conclusion, our results indicate that Sil-Select can be used as a substitute material for sperm preparation instead of Percoll.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.11
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• pp.4545-4548
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• 2014

Objective: To investigate the changes of serum vascular endothelial growth factor (VEGF), soluble interleukin-2 receptor (SIL-2R) and hepatocyte growth factor (HGF) contents in patients with primary hepatocellular carcinoma (HCC) before and after percutaneous microwave coagulation therapy (PMCT) and determine their clinical significance. Materials and Methods: Fasting venous blood (3 mL) from 81 patients with primary HCC diagnosed by pathology was collected in the mornings 1 day before PMCT, and 1 day, 7 days and 1 month after PMCT, and then the serum was separated and stored in $-70^{\circ}C$. The contents of VEGF, SIL-2R and HGF were detected by enzyme linked immunosorbent assay (ELISA). Results: The serum VEGF, SIL-2R and HGF contents in 81 patients with primary HCC had obviously dynamic changes before and after PMCT. By comparison to 1 day after PMCT with pre-operation, there was no statistical significance regarding VEGF and SIL-2R contents (P>0.05), but HGF content showed significant difference (P<0.01). Compared with pre-operation, VEGF, SIL-2R and HGF contents 7 days and 1 month after PMCT all manifested significant differences (P<0.01). By comparison to 7 days with 1 month after PMCT, there was no statistical significance regarding the VEGF content (P>0.05), whereas SIL-2R and HGF contents showed significant change (P<0.01). Conclusions: The contents of serum VEGF, SIL-2R and HGF have obviously dynamic changes in primary HCC before and after PMCT, and their joint detection is expected to be an effective hematologic evaluation index of PMCT for primary HCC.

• Transactions of the Society of Information Storage Systems
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• v.2 no.4
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• pp.224-229
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• 2006

There has been studied flow to minimize the spot size to increase data capacity. Optical data storage devices are being developed near practical limits with wavelength and NA of 405nm and 0.85. There has been studied many types of next generation storage devices such as blu-ray multilayer system, probe based data storage and holographic data storage. Among these data storage devices, solid immersion lens(SIL) based near field recording (NFR) has been widely studied. In this system, SIL is the key component that focuses the laser beam with a very small size which enables ultra high data capacity. Therefore, optical performance evaluation system is required for SIL assembly. In this dissertation, a simple and accurate SIL assembly measurement method is proposed with wedge plate lateral shearing interferometer(LSI). Wedge plate LSI is cheaper than commercialized interferometer, robust to the vibration and the moving distance for phase shifting is large that is order of micrometer. We designed the thickness, wedge angle, material, surface quality and wavelength of wedge plate as 1mm, 0.02degree, fused silica, lamda/10(10-5) and 405nm, respectively. Also, we confirmed simulation and experimental results with quantitative analysis. This simple wedge plate LSI can be applied to different types of SIL such as solid immersion mirror(SIM), hemispherical, super-hemispherical and elliptical SIL.