• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.1
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• pp.87-94
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• 2003

Recently, LPLi(Liquied-Phase LPG injection) system is studied for the new stringent emission regulations. But , there are some problems to be solved such as injector tip icing and fuel leakage for LPLi system development. In this paper, the icing problem near injector tip which leads to difficulty of accurate A/F control was studied and reported. Icing of injector tip and port wall was observed at all the cases in this study regardless of injection duration and angle, air humidity change. The spray angle of LPLi was observed approximately two times wider than that of Gasoline injection. This makes the LPLi spray collide with intake port around injector tip. Temperature of the wetted area was decreased and icing of water vapor contained in intake air because of evaporation of the fuel film. The ice of the injector tip and port wall is also affected by the materials related to heat transfer.

• Proceedings of the KSME Conference
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• 2001.06a
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• pp.316-321
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• 2001

A previous feasibility study for the Korean lead plant, PLiM Phase I, showed a strong possibility of continued operation beyond the original licensed period. In 1998, PLiM Phase II study was initiated aimed at performing additional detailed evaluations on a wider range of components. The objective of this paper is to present the Korean PLiM efforts for Class 1 piping which is identified as one of the critical components with regard to long-term operation. The key findings such as typical design features, degradation mechanisms, technical issues, draft results from the lifetime evaluation for Class 1 piping of the lead plant are briefly described.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.4
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• pp.598-603
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• 1990

This study evaluates the performance of an optical receiver for binary phase shift keying (BPSK) signals in the presence of short noise originating from the photo diode and phase noise of the optical source. The case of using I.O. hybrid compare with the fiber optic hybrid to mix received optical signal and laser local oscillator signal. The impact of these noise is minimized if loop natural frequency and power split ratio between data and carrier recovery branch are choosen optimally. Then it is obtained that required laser linewidt to achieve a BER of 10**-9. The results are the same except theat in case of using the fiber optic hybrid the required optical power is twice as much as the I.O. hybrid.

• Journal of Biomedical Engineering Research
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• v.15 no.2
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• pp.143-150
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• 1994

Wall shear rate or stress is believed to be a major hemodynamic variable influencing atherosclerosis and artery-graft anastomic intimal hyperplasia. The purpose of this study is to verify the effects of radial wall motion, artery-graft compliance and diameter mismatch, and impedance phase angle on the wall shear rate distribution near an end-to-end artery-graft anastomosis model. The results show that radial wall motion of the elastic artery model lowers the mean wall shear rates under pulsatile flow condition by 15 to 20 % comparing to those under steady flow condition at the same mean flow rate. Impedance phase angle seems to have small effects on the mean and amplitude of the wall shear rate distribution. In order to study the effects of compliance and diameter mismatch on the wall shear rates, two models are studied-Model I has 6% and Model I has 6% and Model II has 11% smaller graft diameter. Divergent geometry caused by diameter mismatch near the distal sites reduces the mean wall shear rates significantly, and this low shear region is believed to be prone to intimal hyperplasia.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.11
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• pp.121-129
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• 1998

In-plane ESPI(Electronic Speckle Pattern Interferometry) was devised to measure in-plane deformations and rotation of a specimen with laser in this study. ESPI is a optical measuring method to be able to measure the deformations of engineering components and materials in industrial fields. The conventional measuring methods of surface deformations such as the strain gauge have many demerits because they are contact and point-to-point measuring ones. But that ESPI is noncontact, nondestructive and whole field measuring method can overcome previous disadvantages. We used ESPI which is sensitive to in-plane displacement for measuring in-plane deformations of a disk. And the 4-frame phase shifting method was used for the quantitative analysis. First of all, the system calibration was done due to an in-plane rotation before getting deformations of a disk. Finally we showed good agreement between the experiment results and those of the FEA(Finite Element Analysis).

• Korean Journal of Environmental Biology
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• v.23 no.3 s.59
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• pp.269-274
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• 2005

The 2D/E gel analysis for polypeptide expression reflecting I-18 C gene (early-ecdysterone inducible gene) has conducted the emerged C. riparius adults from larval phase exposure to tebufenozide acting as an ecdysteroidal molting hormone. Control group, the amount of ORE II of the I-18 C gene was larger than that of ORE I of this gene. After treatments, ORE I of the I-18 C gene was overexpressed as the polypeptide, whereas ORF II of this gene was expressed as the polypeptide and was clearly reduced expression. Accordingly, we consider that tebufenozide exhibited endocrine disruptions related processing of ecdysteroid receptor protein reflecting ORF II of I-18 C gene. Also, earlier emergence day was related overexpressed polypeptide reflecting ORE I of I-18 C gene. In this study result, tebufenozide induced changing of physiological condition, and then polypeptide expression reflecting early-ecdysterone inducible I-18 C gene was different between control group and exposure group.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.04a
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• pp.125-130
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• 2004

As an application of GPS is increased by world geodetic system introduction gradually, in this time, It is increased necessary of GPS baseline analysis program development. In this study, I developed a baseline analysis program by L1/L2 carrier. And I compared a baseline analysis result with a commercial program. I showed precision of approximately ${\pm}$1cm in a baseline length in case of Narrow lane as a result that a baseline analysised a developed program.

• The Journal of Korean Medicine
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• v.39 no.4
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• pp.30-39
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• 2018

Introduction: The aim of this study protocol is to share and disclose the methodology used to develop an evidence-based clinical practice guideline (CPG) of therapeutic interventions used in Korean medicine for patients with stroke. Methods: The CPG development process will consist of two phases. In phase I, a development committee will be established, and they will decide the key questions to be answered. A systematic review and meta-analysis will be performed to answer these key questions by searching relevant randomized controlled trials and systematic reviews. Draft recommendations will be developed according to the evidence level and recommendation grades primarily determined using the GRADE methodology. Panels comprised of external experts will be formed, and surveys and a face-to-face meeting will be conducted to reach a consensus on the recommendations. A preliminary guideline will be created after final review by the development committee. In phase II, we will conduct clinical trials and economic analysis to supplement the lack of evidence found in the phase I. Conclusion: The CPG is expected to help doctors practicing Korean medicine in clinics or hospitals with making decisions based on the most reliable evidence, ultimately leading to the provision of optimal care for patients with stroke.

• Proceedings of the KIEE Conference
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• 1997.07a
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• pp.230-233
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• 1997

In this study, design and analysis of 3-phase induction moter are as follows. - Motor characteristics analysis by equivalent circuit ${\cdot}$ Motor characteristics analysis according to variation of rotor slot-tip ${\cdot}$ Motor characteristics analysis according to variation of rotor slot-mouse ${\cdot}$ Motor characteristics analysis according to variation of rotor slot-opening

• Journal of Environmental Science International
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• v.19 no.4
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• pp.447-457
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• 2010

This study aims to monitor the variation of concentration of PCDD/DFs between the gaseous phase-particulate phases in the ambient air of urban area in Korea. This monitoring is evaluated by using the Junge-Pankow model and the Koa absorption model with the application of the Octanol-air partition coefficient. In this study, the ambient air samples were analyzed according to each congener group of the PCDD/DFs by HRGC/HRMS, which have been investigated for the past 5 years. In the results, the annual variation in the concentration level of $\Sigma$PCDD/DFs in TSP was increased from $1588\;fg/m^3$ in 1998 to $5123\;fg/m^3$ in 2002, and from 31 fg I-TEQ/$m^3$ to 94 fg I-TEQ/$m^3$ in the $\Sigma$I-TEQ. In the case of PUF of gaseous phase sample, their variation was increased from $1615\;fg/m^3$ in 1998 to $2237\;fg/m^3$ in 2002, and in the $\Sigma$I-TEQ from 12 fg I-TEQ/$m^3$ to 17 fg I-TEQ/$m^3$. The relative coefficient between the gas phase concentration of PCDD/DFs and the temperature was a value of 0.744; the contributive rate of the temperature to the gaseous phase concentration was 0.554. According to the results, the pattern of the coefficient of distribution based on log $p_L^0$ is similar to the ambient air of the urban areas.