• The Journal of the Korean dental association
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• v.40 no.7 s.398
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• pp.487-487
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• 2002

• Journal of the Korean Society of Propulsion Engineers
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• v.25 no.3
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• pp.89-100
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• 2021

This paper deals with the construction of a combustion test facility and preliminary tests for hot-firing tests of a methane engine. First, the combustion test facility for a 1 kN-class thrust chamber using liquid oxygen/gas methane as propellants was designed and built. Before hot-firing tests, the cold-flow tests of each propellant line and the ignition tests of torch igniter/afterburner were performed to verify propellant supply stability of the combustion test facility, operation of the control and measurement system, and successful ignition. Finally, a preliminary hot-firing test was conducted to measure the combustion efficiency, heat flux, and combustion stability of a thrust chamber prototype. The constructed combustion test facility will be helpfully used for basic research and development of methane engine thrust chambers.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.885-891
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• 2011

This paper describes the results of preliminary design of rocket engine test facility for the performance evaluation of liquid rocket engine. Design specification and composition of rocket engine test facility are suggested based on the design requirements. The results of the preliminary design of rocket engine test facility will be used as base data for the detail design and construction of rocket engine ground test facility of KSLV-II 75tonf liquid rocket engine.

• 치위협보
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• s.103
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• pp.1-16
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• 2006

• Korean Journal of Comparative Education
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• v.27 no.4
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• pp.231-254
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• 2017

The purpose of this study was to identify the actual condition and problems of Mongolian teacher quality management of selection and qualification and to recommend improvement. We examined the Mongolian teacher qualification management system with four criteria based on previous research. The results of this study are as follows. Mongolian government established quality management mechanisms such as selection of pre-service teachers, verification of teacher certificate, and appointment of in-service teachers, and teacher qualification standards. These Mongolian teacher selections and qualification systems were operated to attract the manpower required for teaching, to verify their qualifications and to induce professional development. However, the systems have not been able to verify the teachers' ability to practice in the field. We also found that the systems themselves were criticized for failing to guarantee conformity, fairness and transparency. Based on the results of this study, we discussed and draw policy implications for improvement of teacher quality management of selection and qualification in Mongolia.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.11a
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• pp.155-158
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• 2007

As a secondary stage of the liquid rocket engine development test, turbopump-gas generator powerpack tests are being performed. The schematics of the test hardware and the test facility for the TP+GG coupled test are presented. The results of a preliminary test results for the verification of the propellant supply system of the test facility are also presented. Based on the preliminary tests results, the verification of the propellants supply systems of the facility system was performed.

• Journal of the Korean Society of Propulsion Engineers
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• v.5 no.3
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• pp.60-70
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• 2001

The study of compatible liner with ADP-505 propellant based PCP was performed. HTPB/DDl was chosen as a binder of liner in order to prohibit migration of nitroester plasticizer from propellant. The possible formulations for liner were screened by peel test of EPDM insulation/liner, propellant/liner and insulation/liner/propellant. Also, the adhesion tests including tension and shear were conducted. The adhesion of liner and propellant fumed out to be very good. The peel value was shown 1.5∼1.8 daN/cm, tensile force was 5.5∼6.0bar and shear force was 4.2∼5.0bar. In the samples of insulation/liner/propellant, they also have shown good adhesion properties. The peel, tensile and shear strength were 1.8 daN/cm, 5.0∼6.0bar and 4.5∼5.0bar, respectively.

• Journal of the Korean Society of Propulsion Engineers
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• v.24 no.1
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• pp.1-8
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• 2020

In this study, a configuration design of a CH₄/LOx small rocket engine was made and test system was established for the performance evaluation. A coaxial swirl injector was chosen because of its remarkable atomization performance and low combustion instability. Three aspect ratios for the combustion chamber configuration, i.e., 1.5, 1.8, and 2.1 were also set for the comparison of the combustion efficiency. The reliability of the thrust measurement rig was enhanced by pre-and post-calibration process. From the preliminary ground hot-firing test, the measured thrust and specific impulse values were 89.2 N and 181.8 s, respectively, which were 21.6% lower than the ideal values. In addition, the efficiency of characteristic velocity was measured as 84.2%.

• Applied Biological Chemistry
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• v.19 no.4
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• pp.183-188
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• 1976

In order to establish methods of potato processing for mixed cooking with rice as main dish, the size and shape of potato granules and favorable ratio of potato granules to rice for cooking were studied preliminary. As the results cylindrical shaped potato granule of around 6mm in diameter and $10{\sim}13mm$ in length are more favorable than rectangular shape for mixed cooking according to panel test. Mixed cooking of 30% of treated potato granules with rice is the most favorable in the point of palatability.

• Korean Journal of Acupuncture
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• v.31 no.1
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• pp.33-39
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• 2014

Objectives : This study was designed to evaluate the feasibility of further acupuncture research as an effective and safe treatment for reducing cancer-related upper abdominal pain in patients treated with Neurolytic celiac plexus block(NCPB). Methods : This study is a randomized controlled pilot clinical trial of 3-week duration. Fourteen patients will be recruited and randomly allocated to 2 groups: an acupuncture plus NCPB group(experimental group) and a NCPB group(control group). All patients will undergo one session of NCPB, but only the experimental group will receive three acupuncture sessions a week for 2 weeks(6 in total). The primary outcome will be measured using the visual analogue scale, and the secondary outcome will be measured using the Painvision system and the consumption of additional analgesics. Assessments will be made at baseline and at 1, 2, and 3 weeks thereafter(that is, the 3-week assessment will be made 1 week after treatment cessation). Conclusions : This clinical trial will inform the design of a full-scale trial. The outcomes will provide information to facilitate the incorporation of acupuncture into existing pain management methods such as NCPB in the treatment of cancer-related upper abdominal pain patients.