• Title/Summary/Keyword: Lew

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Detection of Clarithromycin-resistant Strains from Clinical Isolates of Mycobacterium abscessus (Clarithromycin 약제에 대한 Mycobacterium abscessus 임상 내성 균주 분리)

  • Lee, Seung Heon;Park, Young Kil;Ryo, Sung Weon;Shim, Myung Sup;Lew, Woo Jin;Kim, Hee Jin
    • Tuberculosis and Respiratory Diseases
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    • v.64 no.6
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    • pp.422-426
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    • 2008
  • Background: Mycobacterium abscessus is the most pathogenic and drug-resistant rapid-growing mycobacterium. Clarithromycin or azithromycin are the only regular oral antimycobacterial agents that have an effect on M. abscessus. We tried to detect the clarithromycin-resistant strains from the clinical isolates of M. abscessus. Methods: We tried to isolate the clarithromycin-resistant strains from 220 clinical isolates of M. abscessus by performing using reverse hybridization assay (RHA) and the broth microdilution test (BMT). Results: Seven resistant strains (3.2%) from all the tested clinical isolates were detected by BMT. Three of these resistant strains were also detected by RHA and it was confirmed that they had point mutants. Conclusion: These results showed that clarithromycin resistance in M. abscessus clinical isolates is related to a point mutation and other unknown mechanisms.

Linear Analysis of Water Surface Waves Generated by Submerged Wave Board Whose Upper and Lower Ends Oscillate Horizontally Freely (상하단이 자유롭게 수평동요하는 수중 조파판에 의해 생성된 수면파의 근사해석)

  • Kim, Hyochul;Oh, Jungkeun;Kwon, Jongoh;Lew, Jae-Moon
    • Journal of the Society of Naval Architects of Korea
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    • v.56 no.5
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    • pp.418-426
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    • 2019
  • To derive a simplified analytic solution which can be utilized as a fundamental solution for the wave maker design, a segment of the wave board has been idealized as a submerged line segment in a two dimensional domain of a wave flume. The lower end of the line segment could be located at arbitrary depth of the wave flume and the upper end of the board could be also submerged to any depth from the free surface. The freely oscillating motion of the wave board is assumed to be defined by determining the condition of horizontal oscillation on both ends differently. The submerged wave board oscillating in horizontal direction could be specified by selecting the amplitude, frequency and the phase lag differently on lower and upper ends of the board. The simplified two dimensional wave generated by the wave board segment has been obtained by the first order perturbation method. It is found that the general solution of the freely oscillating wave board in two dimensional domain could be decomposed into the solution of flap motion with lower end hinge and swing motion with upper end hinge. The case study of the analytic solutions has been carried out to evaluate the effect on the wave height due to the difference of oscillation frequency, phase difference and variation of stroke between for the motion of both ends. It is found that the solution of the freely oscillating wave board could be utilized for the development of high performance wavemaker especially for irregular waves.

Calculation of Wave Resistance of a Hybrid Hydrofoil (복합지지형 고속선의 조파저항 계산)

  • Yoo, J.H.;Kim, Y.G.;Lew, J.M.
    • Journal of the Society of Naval Architects of Korea
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    • v.33 no.1
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    • pp.1-8
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    • 1996
  • A potential-based panel method has been developed for numerical computation of wave resistance on a hybrid hydrofoil. Hybrid hydrofoil is composed of a main body, two struts and two hydrofoils. The main body, which is assumed to be an axisymmetric body for the present analysis, is normally used to support displacement of a body with its buoyancy. Normal dipoles and the sources are distributed on the body(main body, struts, hydrofoils) and the sources are distributed on the free surface. Linearized free surface and the radiation conditions are satisfied using the fourth order finite difference operator and the semi-linear pressure Kutta condition is used for the numerical computation of the hydrofoils. Poisson type free surface condition has been used for the numerical computation and hyperboloidal panel method has been used for better numerical accuracy. To verify this numeric method, model tests are performed in circulation water channel. From the comparison of experimental results with numeric ones, the present method can be used as a useful tool for the design of high speed vessels.

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Application of a Potential-Based Panel Method for Analysis of a 2-Dimensional Cavitating Hydrofoils Advancing Beneath a Free-Surface (자유수면 아래서 유한 Froude 수로 전진하는 2차원 수중익의 부분 및 초월 공동 유동 문제 해석)

  • J.M. Lew;C.S. Lee;Y.G. Kim
    • Journal of the Society of Naval Architects of Korea
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    • v.30 no.2
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    • pp.112-122
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    • 1993
  • A potential-based panel method is presented for the analysis of a partially or supercavitating two-dimensional hydrofoil at a finite submergence beneath a free surface, treating without approximation the effects of the finite Froude number and the hydrostatic pressure. Free surface sources and normal dipoles are distributed on the foil and cavity surfaces, their strength being determined by satisfying the kinematic and dynamic boundary conditions on the foil-cavity boundary. The cavity surface is determined iteratively as a part of the solution. Numerical results show that the wave profile is altered significantly due to the presence of the cavity. The buoyancy effect due to the hydrostatic pressure, which has usually been neglected in most of the cavitating flow analysis, is found playing an important role, especially for the supercavitating hydrofoil; the gravity field increases the cavity size in shallow submergence, but decreases it when deeply submerged, while the lift reduces at all submergence depth.

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Palatal Mucoperiosteal Island Flaps for Palate Reconstruction

  • Kim, Hong Youl;Hwang, Jin;Lee, Won Jai;Roh, Tai Suk;Lew, Dae Hyun;Yun, In Sik
    • Archives of Craniofacial Surgery
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    • v.15 no.2
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    • pp.70-74
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    • 2014
  • Background: Many options are available to cover a palatal defect, including local or free flaps. The objective of this study was to evaluate the usefulness of palatal mucoperiosteal island flap in covering a palatal defect after tumor excision. Methods: Between October 2006 and July 2013, we identified 19 patients who underwent palatal reconstruction using a palatal mucoperiosteal island flap after tumor excision. All cases were retrospectively analyzed by defect location, size, tumor pathology, type of reconstruction, and functional outcomes. Speech and swallowing functions were evaluated using a 7-point visual analog scale (VAS) score. Results: Among the 19 patients, there were 7 men and 12 women with an age range of 25 to 74 years (mean, $52.5{\pm}14.3$ years). The size of flaps was $2-16cm^2$ (mean, $9.4{\pm}4.2cm^2$). Either unilateral or bilateral palatal island flaps were used depending on the size of defect. During the follow-up period (mean, $32.7{\pm}21.4$ months), four patients developed a temporary oronasal fistula, which healed without subsequent operative. The donor sites were well re-epithelized. Speech and swallowing function scores were $6.63{\pm}0.5$ and $6.58{\pm}0.69$ on the 7-point VAS, indicating the ability to eat solid foods and communicate verbally without significant disability. Conclusion: The palatal mucoperiosteal island flap is a good reconstruction modality for palatal defects if used under appropriate indications. The complication rates and donor site morbidity are low, with good functional outcomes.

Analysis of Electric Shock Accidents and Check Results in Domestic and Foreign low-Voltage Handhole (국내.외 저압지중함 감전사고사례 및 점검결과의 분석)

  • Kim, Chong-Min;Han, Woon-Ki;Bang, Sun-Bae;Kim, Han-Sang;Shim, Keon-Bo
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.22 no.1
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    • pp.124-131
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    • 2008
  • Recently underground electrical power distribution is increased because people attach importance to aesthetics of the downtown areas. Lew-voltage handhole of underground distribution line for joint and branch point is mainly installed at the sidewalk. So, pedestrian can get a electric shock if fault is occurred in the low-voltage handhole. Furthermore the street was flooded by recently an unusual change in the weather. Fault is occurred in the low-voltage handhole that may create a shock hazard for the human body because a person's body resistance lower due to effect of water. This paper analyses causes of electric shock accidents and check results at the low-voltage handhole. At a result of analysis, the causes of electric shock accidents in domestic and foreign low-voltage handhole are same but environmental conditions of low-voltage handhole are different In the future, the analytical data can be applied to prevent the electric shock at the low-voltage handhole, and can be used to basic data for the improving installment of low-voltage handhole.

Implementation of the automatic switching device for the voice communications between heterogeneous devices (이종 기기 간 음성통신을 위한 자동전환장치의 구현)

  • Lew, Chang-Guk;Lee, Bae-Ho
    • The Journal of the Korea institute of electronic communication sciences
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    • v.10 no.12
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    • pp.1321-1328
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    • 2015
  • A radio is a half-duplex voice communication method using the PTT(: Push To Talk), occupy a single line calls during transmission. As an interface between the telephone and the radio, UHF and VHF, for voice communication between the different heterogeneous devices, A device automatically switches between the two devices is required. Therefore, in accordance with the performance of the voice switching apparatus for detecting a voice to be transmitted from an input signal, loss of the audio signal to be transmitted is subjected to Significant influence. Conventional method has the problem responding to noise by setting the level through simple means of amplitude of input signal, in other words, the energy level of the input signal. This paper, by using the audio signal processing techniques, this discriminated what the voice is among the input signal and substantiated a device for the automatic voice transmission between heterogeneous devices. With this proposal, I was confirmed of improvement of performance in the automatic voice switching device, could perform loss-less transmission of voice between heterogeneous devices.

The Anti-melanogenic Effect of Whitening Agent Containing Arbutin and ${\beta}-Glucosidase$ (알부틴과 베타-글루코시다제를 함유하는 미백 화장품의 항멜라닌 효과)

  • Lew Bark-Lin;Ryou Ji-Ho;Lee Mu-Hyoung
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.30 no.3 s.47
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    • pp.415-418
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    • 2004
  • Arbutin is a glycosylated hydroquinone found at high concentration in certain plants capable of surviving extreme and sustained dehydration. It has been reported to have an inhibitory effect of melanogenesis and to be hydrolyzed easily to yield glucose and hydroquinone by ${\beta}-glucosidase.$ While hydroquinone also has an anti-melanogenic effect, however, is carefully used as a topical whitening agent because of side effects. The present study was undertaken to examine the inhibitory effect of an whitening agent containing arbutin and ${\beta}-glucosidase$ on UV radiation induced pigmentation in human skin. Experimental subjects were UVB-irradiated on the back. UVB-irradiated areas were assigned to three groups: arbutin and ${\beta}-glucosidase$ treated group, vehicle control, and no-application control. Arbutin and ${\beta}-glucosidase$ treatment inhibited pigmentation by 50.17 percent, compared with the controls (N : 10: P<0.05). These results suggest that the whitening agent containing arbutin and ${\beta}-glucosidase$may be used as an agent to inhibit melanin formation induced by UV radiation.

Determination of global ice loads on the ship using the measured full-scale motion data

  • Lee, Jae-Man;Lee, Chun-Ju;Kim, Young-Shik;Choi, Gul-Gi;Lew, Jae-Moon
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.8 no.4
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    • pp.301-311
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    • 2016
  • This paper describes the whole procedures to determine ice-induced global loads on the ship using measured full-scale data in accordance with the method proposed by the Canadian Hydraulics Centre of the National Research Council of Canada. Ship motions of 6 degrees of freedom (dof) are found by processing the commercial sensor signals named Motion Pak II under the assumption of rigid body motion. Linear accelerations as well as angular rates were measured by Motion Pak II data. To eliminate the noise of the measured data and the staircase signals due to the resolution of the sensor, a band pass filter that passes frequencies between 0.001 and 0.6 Hz and cubic spline interpolation resampling had been applied. 6 dof motions were computed by the integrating and/or differentiating the filtered signals. Added mass and damping force of the ship had been computed by the 3-dimensional panel method under the assumption of zero frequency. Once the coefficients of hydrodynamic and hydrostatic data as well as all the 6 dof motion data had been obtained, global ice loads can be computed by solving the fully coupled 6 dof equations of motion. Full-scale data were acquired while the ARAON rammed old ice floes in the high Arctic. Estimated ice impact forces for two representative events showed 7e15 MN when ship operated in heavy ice conditions.

A study on the impact load acting on an FPSO bow by steep waves

  • Hong, Sam-Kwon;Lew, Jae-Moon;Jung, Dong-Woo;Kim, Hee-Taek;Lee, Dong-Yeon;Seo, Jong-Soo
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.9 no.1
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    • pp.1-10
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    • 2017
  • Various offshore structures such as FPSO, FSO, Semi-submersible, TLP and Spar are operated to develop offshore oil and gas fields. Most of the offshore structures shall be operated over 20 years under the harsh environments at sites so that the offshore structures should be designed to endure the harsh environments. In this study, the effect of the impact load (so called slapping load) by the steep waves acting on the FPSO bow is investigated through the model test. For measurement of the impact pressures on the frontal area, a bow-shaped panel was fabricated, and installed the pressure sensors on the bow starboard side of the model FPSO. During the model test campaign, the impact load was investigated using the steep waves with $Hs/{\lambda}$ greater than 1/16 of the representative wave condition. Consequently, it is confirmed through the model test that the impact loads acting on the FPSO bow are significantly increased with the steep waves ($Hs/{\lambda}$ > 1/16) than the representative wave conditions of a maximum significant wave height and a pitch forcing period. Therefore, for safe design of North Sea FPSO, it is necessary to consider the steep waves in addition to the representative wave conditions and to be applied as proper structural load. Also, the effect of random seeds in irregular waves should be considered to build the safe FPSO.