• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.9
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• pp.1066-1074
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• 2004

With a diode corona charger, which is a component of ELPI(Electrical Low Pressure Impactor), aerosol particles are charged to make electrical detection possible before they are collected by the impactor. We designed and evaluated two cylindrical corona chargers, each of which had a central corona needle electrode. For the performance evaluation of each corona charger the polydisperse dioctyl sebacate(DOS) particles, with diameters of 0.1∼0.8 $\mu$m and NaCl particles, smaller than 0.1$\mu$m, were used. The particles were then led through an electrostatic classifier (TSI model 3081) to classify monodisperse aerosol with minimal size deviation. After evaluating the wall loss of the particles in the corona charger, we measured the product of penetration and number of charges, Pㆍn, to evaluate the corona charger efficiency at high positive voltages of 4, 5, 6 kV.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1417-1422
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• 2003

An electrical cascade impactor is a multistage impaction device to separate airborne particles into aerodynamic size classes using electrical method. We designed a real-time three-stage electrical low-pressure impactor, which is proper to nanometer sized environmental aerosols. Performance evaluation was carried out for stage 1 and 2. The monodisperse liquid dioctyl sebacate (DOS) particles were generated using condensation-evaporation followed by electrostatic classification using DMA (differential mobility analizer) for particles with diameters in the range of $0.04{\sim}0.8{\mu}m$. The evaluation of the electrical impactor is based on the use of two electrometers, one connected to the impaction plate of the impactor, and the other to the faraday cage as backup filter. The results showed that the experimental 50% cutoff diameters in the operation pressure were 0.53 and $0.12{\mu}m$ for stage 1 and stage 2. The effect of operation pressure on the cutoff diameter and the steepness of collection effcieicy curves is investigated.

• Investigative Magnetic Resonance Imaging
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• v.12 no.2
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• pp.206-210
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• 2008

Aggressive angiomyxoma is a rare tumor that predominantly occurs in the female genital tract. Because of its high tendency for local recurrence, preoperative diagnosis is important to ensure wide excision and reduce recurrence risk. But it is often misdiagnosed due to its rarity. We present two cases of aggressive angiomyxoma: a recurrent case that was initially misdiagnosed and a preoperatively diagnosed case.

• YAKHAK HOEJI
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• v.41 no.2
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• pp.187-194
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• 1997

For the development of antifungal agents, modification of naftifine which exhibits significant antimycotic activity was performed by replacing the naphthalene ring of it to hete ro cyclic rings such as morpholine. benzothiazole, piperidine and pyridine derivatives. The synthesized compounds were tested in vitro antifungal activity against five different fungi with naftifine as a comparative antimycotic molecule. From the biological evaluation two compounds, (E)-N-(3-phenyl-2-propenyl)-N-(4-piperidinylmethyl)amine(3d) and (E)-N-(3-phenyl-2-propenyl)-N-(3-pyridylmethyl)amine(3f) showed relatively noticeable activity(MIC=50${\mu}g$/ml). On the other hand, the other compounds had no activity.

• Korean Journal of Optics and Photonics
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• v.21 no.1
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• pp.12-15
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• 2010

In this paper, we have proposed and demonstrated a simple fiber-optic temperature sensor based on the bending loss of a TEC(thermally expended core) fiber attached to a bi-metal. The deformation of the bi-metal caused by the change in its temperature induces the bending loss of the TEC fiber. The experimental result shows that the temperature sensitivity and operation temperature range of the device are controllable through the adjustment of the structure of the expanded core fiber. The fabrication procedure of the device is described in detail.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.2
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• pp.161-169
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• 2012

Recently, a study for the functional surface production of super hydrophobic of natural and biomimetic artificial has attracted much attention. To make process methods of super hydrophobic surface has a variety of ways such as lithography, etching, and laser ablation. However, we were used ultra-shot pulse laser ablation process which has the virtue of more environmental friendliness and simple process. In this paper, we were fabricated a multiplicity of super hydrophobic patterns on mold surface(NAK80) using by optimizing the laser processing conditions and it was transferred on PDMS. Also, we measured contact angle super hydrophobic patterns on PDMS. The result showed there is no patterns on PDMS were measured 94 degrees, by contrast, optimized super hydrophobic patterns on PDMS was 157 degrees. Therefore we fabricated super hydrophobic surface on mold. Based on these experimental results, it is possible to mass production using ultra shot pulse laser ablation of super hydrophobic pattern and to be applied for a variety of industries.

• Journal of the Korean Institute of Gas
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• v.15 no.4
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• pp.1-6
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• 2011

Risk-based inspection (RBI) is a inspection technique suggesting inspection plan, such as inspection interval and inspection method, of the pressurized facilities based on its risk in the petrochemical, refinery and gas industries. Therefore, we can intensively and cost-effectively maintain, repair and manage the high-risk facilities through RBI technology. This paper reviews RBI technology, such as principle and implemental procedure of RBI, management of risks and facilities and return of investment through RBI, RBI technology at present and its application in domestic industries. In addition, some improvement directions of RBI are also proposed.

• Journal of Yeungnam Medical Science
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• v.30 no.1
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• pp.47-50
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• 2013

There has been an increase in the number of reports of atypical manifestations of Graves' disease (GD), such as jaundice, anemia, thrombocytopenia and leukopenia. Pancytopenia also rarely occurs in GD. In this paper, a case of pancytopenia with GD that was successfully treated with an anti-thyroid drug is reported. In this case, a 69-year-old woman showed pancytopenia with a normal peripheral blood smear, bone marrow aspiration smear and bone marrow biopsy. Her thyroid function test and thyroid scintigraphy confirmed her hyperthyroid status. Her laboratory abnormality and clinical condition improved after she was treated with an anti-thyroid drug. This is a rare case of pancytopenia associated with GD.

• BMB Reports
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• v.41 no.6
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• pp.461-465
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• 2008

IL-18 production may enhance immune system defense against KG-1 cells ; NB4 cells, which are associated with good prognosis, do not produce IL-18. In this study, we treated KG-1 cells with IL-18 and used microarray technology to assess subsequent effects on gene expression. In UniGene-array of 7488 human genes, expression of 57 genes, including stress related genes, increased at least 2-fold, whereas expression of 48 genes decreased at least 2-fold. Following exogenous exposure of KG-1 cells to IL-18, expression of CRYGC, $NF{\kappa}BIA$ and NACA gene were monitored. The latter is a transcriptional coactivator potentiating c-Jun-mediated transcription.$NF{\kappa}BIA$ is an inhibitor of $NF{\kappa}B$, and affects growth regulation, apoptosis and hypoxic stress. Studies, such as this one, are beginning to clarify the differences between cells associated with good and bad cancer prognoses, which may ultimately assist in medical treatment for acute myeloid leukemia.

• Journal of Mechanical Science and Technology
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• v.20 no.5
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• pp.652-657
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• 2006

Although many methods about the control of irregular external noise have been introduced and implemented, it is still necessary to design a controller that will be more effective and efficient methods to exclude for various noises. Accumulation of errors due to model tracking, internal noises (thermal noise, shot noise and 1/f noise) that come from elements such as resistor, diode and transistor etc. in the circuit system and numerical errors due to digital process often destabilize the system and reduce the system performance. New stochastic controller is adopted to remove those noises using conventional controller simultaneously. Design method of a model tracking dual controller is proposed to improve the stability of system while removing external and internal noises. In the study, design process of the model tracking dual stochastic controller is introduced that improves system performance and guarantees robustness under irregular internal noises which can be created internally. The model tracking dual stochastic controller utilizing F-P-K stochastic control technique developed earlier is implemented to reveal its performance via simulation.