• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.20 no.2
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• pp.136-140
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• 2009

Background and Objectives: Recurrent respiratory papillomatosis (RRP) is difficult to treat because of its tendency to recur and spread throughout the aerodigestive tract. We aimed to estimate the effect of intralesional injections of cidofovir in patients with RRP. Materials and Method: Within the period from January 2003 to July 2007, 13 patients aged 2 to 61 years were treated with intralesional injections of cidofovir combined with surgical excision of RRP. Cidofovir was injected intralesionaly at a concentration of 5 mg/cc after complete removal of the papilloma with $CO_2$ laser or microdebrider. We evaluated the effect of intralesional cidofovir therapy by comparing pre-treatment mean interval of recurrence with post-treatment interval of recurrence. Results: Of 13 patients, two patients showed complete response during follow up period and four patients showed partial response. Seven patients did not respond to cidofovir at all. Mean pre-treatment mean interval of recurrence was 9 months and mean post-treatment interval of recurrence was 13.1 months (p=0.039). There was a statistical significance between the injected dose of cidofovir and post-treatment interval of recurrence (p=0.009). There were no local or systemic side effects caused by cidofovir. Conculsion : Intralesional injection of cidofovir seems to have a potential of a safe and effective adjuvant therapy of RRP. There was a positive correlation between the injected dose of cidofovir and patient clinical outcomes so that administration of higher doses and more frequency of injections should be needed to reduce recurrence. Further study regarding injection therapy regimen for RRP is required.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.38 no.11
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• pp.791-803
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• 2001

Mach-Zehnder type traveling-wave Ti：LiNb $O_3$ optical modulators were designed and fabricated. Optimum parameters of optical waveguides were calculated by means of the FDM. Design of CPW traveling-wave electrodes were performed by the FEM in the active region and by the CMM in the input/output section to obtain the conditions of MW effective index and impedance matching. From the measured S parameters, MW characteristics of the traveling-wane electrodes were extracted to be ${\alpha}_m$=0.05426 $\sqrt{f}$, $N_{eff}$=2.2025, and $Z_{c}$=39 ${\Omega}$. The calculated optical response R($\omega$) showed the 3 dB bandwidth of 10 GHz.z..

• Biomedical Science Letters
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• v.12 no.2
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• pp.119-125
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• 2006

In relation to the tissue engineering, the cellular responses to the morphology of the scaffold surface are interesting topics. Human ligament fibroblasts (HLFs) were cultured on the micrpatterned silicone substrates subjected to cyclic stretch to simulate ligament motion. Groove and ridge width of silicone substrates was 10/50, 20/50, 20/10, and 20/20 ${\mu}m$ (groove/ridge ${\mu}m$) with a depth of $3{\mu}m$. Strain was applied over two days for 4 hours per day with a frequency of 0.5 Hz with the magnitudes of 4 or 8%. The purpose of this study was to evaluate ligament fibroblast alignment and cellular responses in relation to the pattern of microgrooved surface and stretching magnitude. Ligament fibroblasts in the microgrooved surface were elongated and aligned parallel to the microgrooves under no stretch. Uniaxial cyclic stretch induced cellular activities and their orientation rise in cellular response and the cells showed alignment and elongation perpendicular to the direction of the stretch. Biochemical analyses showed that the best cellular response was found on the $20/50{\mu}m$ under 8% stretch. The surface morphology and mechanical stretching were found to contribute to increase of proliferation, collagen production.

• Journal of the Korean Society for Nondestructive Testing
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• v.20 no.1
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• pp.33-37
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• 2000

The 1-3 piezoelectric composite transducer with 75 volume percents PZT was fabricated by the dicing-filling method. The resonance modes of the 1-3 transducer have been studied with electric impedance measurement as a function of frequency. The fundamental frequencies of the planar and thickness mode were observed at 0.95MHz and 1.63MHz respectively, but the lateral mode was not observed. In the thickness mode, the electromechanical coupling coefficient of the 1-3 piezoelectric composite transducer, 0.54, was very closed to that of the single phase PZT(0.52). The pulse-echo response by exciting the 1-3 transducer with an electric pulse was observed from the water/reflector interface, and analyzed bandwidth by the spectrum of the impulse response. The quality factor Q for the 1-3 transducer was observed as 1.5 smaller than that of the single phase(80) and then the 1-3 transducer may be used to the broad band type transducer applications.

• Journal of Sensor Science and Technology
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• v.13 no.5
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• pp.329-334
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• 2004

Functional residual capacity (FRC) is an important diagnostic parameter measured using $N_{2}$ analyzer. Since $N_{2}$ analyzer is expensive as well as cumbersome for use of noisy vacuum pump, the FRC measurement becomes possible only in large well-equipped hospitals. The present study introduced a new $TN_{2}$ wash-out technique to measure FRC by $O_{2}/CO_{2}$ analysis, which is relatively cheaper and much simpler to apply. Slower $O_{2}$ response was compensated for high frequency to be coincided with $CO_{2}$ response, thereby enabled indirect, but accurate $N_{2}$ concentration measurement. FRC was estimated by continuous integration of expired $N_{2}$ volume obtained with air flow signal. Experiment with 3 L syringe, a standard calibration device recommended by the American Thoracic Society, demonstrated less than 1% error at 0, 1, and 2 L. Correlation coefficient was almost ideal, guaranteeing linear estimation of FRC. The present technique is inexpensive and simple to apply, thus should he of great convenience.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.8
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• pp.693-700
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• 2008

The primary mirror system in a satellite camera is an opto-mechanically coupled system for a reason that optical and mechanical behaviors are intricately interactive. In order to enhance the opto-mechanical performance of the primary mirror system, opto-mechanical behaviors should be thoroughly investigated by using various analysis procedures such as elastic, thermo-elastic, optical and eigenvalue analysis. In this paper, optimal design of the bipod flexure mounts for high opto-mechanical performance is performed. Optomechanical performances considered in this paper are RMS wavefront error under the gravity and thermal loading conditions and 1st natural frequency of the mirror system. The procedures of the flexure mounts design based on design of experiments and statistics is as follows. The experiments for opto-mechanical analysis are constructed based on the tables of orthogonal arrays and analysis of each experiment is carried out. In order to deal with the multiple opto-mechanical properties, MADM (Multiple-attribute decision making) is employed. From the analysis results, the critical design variables of the flexure mounts which have dominant influences on opto-mechanical performance are determined through analysis of variance and F-test. The regression model in terms of the critical design variables is constructed based on the response surfaceanalysis. Then the critical design variables are optimized from the regression model by using SQP algorithm. Opto-mechanical performance of the optimal bipod flexure mounts is verified through analysis.

• The Journal of Korean Medicine
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• v.25 no.2
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• pp.207-219
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• 2004

Objectives : We investigated to find the relationship between single-nucleotide polymorphism (SNP) of IL4R, IL-10 and bee venom therapy efficacy in patients with RA treated with bee venom for 8 weeks. Methods : Korean RA patients (n=114) and healthy subjects (n=109) were included in this prospective study. Korean bee venom was dissolved in saline (diluted 1:3000) and administrated into acupuncture points. Bee venom therapy was applied twice a week and continued for 8 weeks. The clinical response was evaluated using various assessments before and after treatment. Disease severity was measured by determining the number of tender joints and swollen joints. Laboratory studies included ESR, CRP, and rheumatoid factor. Genotyping for IL-4R and IL-10 polymorphism was done by pyrosequencing analysis. Results : 1. In IL4R genotypes, there was significant difference between RA ptitients tind controls group. 2. In IL4R genotypes, there was significant difference among Good, Mild and Bad responders to in RA patients, but in the frequency of alleles and carriers, there were no significant difference. 3. There was no significant difference between RA patients and controls group in IL-10 gene genotypes. 4. In IL-10 genotypes, there was no significant difference among Good, Mild and Bad responders to in RA patients. 5. There was no significant difference in the improvement of ESR, CRP and KHAQ scores after bee venom therapy in RA patients among the IL4R or IL-10 genotypes. Conclusions : In IL-4R genotypes, there was significant difference between RA patients and control group, and among Good, Mild and Bad responders in RA patients. However, in IL-10 genotypes, there was no significant difference between RA patients and controls group and among Good, Mild and Bad responders in RA patients.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.3
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• pp.317-323
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• 2011

We use the finite element method to analyze the seismic design of a liquid storage tank for a polar crane at a nuclear power plant. We obtained the natural frequency and vibration modes by modal analysis, and we evaluated the seismic stability by response spectrum analysis. Furthermore, the seismic analysis of the tank was accomplished by analyzing not only the forces applied to the wall by the sloshing of the liquid, but also the safe-shutdown earthquake condition for the tank. We propose a seismic-design process and a seismic-analysis method for liquid storage tanks based on the commercial finite element analysis program, ANSYS.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.100.1-100.1
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• 2011

Electrochemical impedance spectroscopy(EIS) are using widely as a useful technique mainly in the field of electrochemical for the analysis of electrode reactions or characteristics of the composites. The response analysis of the systems technique provides comprehensive informations about the characteristic and structure of complex and internal reaction. The EIS is the method to measure impedance of the measurement target classified by the frequency, it select the equivalent impedance model to give same response from the result and it calculate the parameter. Therefore, the chemical reaction inside the fuel cell is to modeling to electrical impedance. And as repeating the same experiment in each of the operating point, we can get each different parameter. As a result, we can establish the equivalent impedance model in each operating point. Therefore, if we use these models, we can evaluate the fuel cell without the internal design parameter of the fuel cell as required in existing modeling. The EIS is used typically technique for distinguish status of fuel cell called SOH(State Of Health). When the fuel cell is degradation, Efficiency and health of the fuel cell is reduced because internal impedance is increase. As usage of these principles, we can evaluate state of fuel cell through the impedance analysis of fuel cells. In this study, we are presents EIS distinction system and algorithm for residential fuel cell systems. At the time of the fuel cell installation in the fields, the EIS system and proposed algorithm will be able to apply as technique for efficiency and performance evaluation about fuel cell system.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.18 no.1
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• pp.53-62
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• 2006

Structural measurements obtained from accelerometers, strain gauges. and tilt meters at Ieodo ocean research station was analyzed. In the acceleration signals, dynamic characteristics of the station were round by using the measured dynamic responses under different wave attacks and were compared with those by numerical analysis. Data from strain gauges and tilt-meters were also analyzed to identify the present state of dynamic response. Effect of wave height on the dynamic characteristics were investigated. The present results and those which will be measured and analyzed later can be used to identify and to assess the state of the station whether it is health or not.