• The Journal of the Korea Contents Association
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• v.8 no.4
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• pp.92-99
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• 2008

Most of existing Ceramic bottle has a problem because of the entrance facing the upper, and then having the entrance exposed in the outside. This study has made up for this problem and manufactured a bottle having dual structure. This bottle contains the contents being poured, has the containing part having the entrance in the lower part, multiple connecting passage hole connected with the water containing part in the upper, and the storage part, keeping contents, located in the circumference of the water containing part. The tail end of the entrance of the water containing part is located more upper than the lower part of a storage part, being at the bottom. This bottle has a dual structure of which the entrance faces the lower part. So, because of checking a foreign substance to be inflowed, restraining the diffusion of an alcohol ingredient, it is possible to have the custody of products, having alcohol element, and other contents for a long time. And then, the water containing part, through the connecting hole, always can pour the contents of a certain level in a cup or bowl. Accordingly, the purpose of this study is to make a convenient, a practicable bottle with having settled problems of customary know-how explained previously.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.7 no.3
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• pp.501-511
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• 1995

A numerical model for predicting the performance of gas distrubutor type double inlet pulse tube refrigerators has been developed. The model was based on adiabatic analysis and the losses of heat exchangers and regenerator were considered. Thermodynamic behavior of working fluid within a double inlet pulse tube refrigerator was investigated and the effects of design parameters, such as valve and orifice openings, cold heat exchanger temperature, frequency and pulse tube length, on the cooling capacity and COP were shown.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.05a
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• pp.442-443
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• 2001

강진만은 삼천포수도, 노량수도와 지족수도를 통하여 유입되는 조류(tidal current)에 의해 해양생태계의 구성인자들이 영향을 받고 있다. 이중 강진만북부 입구와 만에서는 피조개와 굴양식이 활발히 행하여지고 있는 해역이다. 또한, 삼천포수도와 노량수도 입구에는 삼천포 하동화력 발전소가 위치하여 직, 간접적으로 온배수의 영향이 이들 해역의 생산력에 영향을 미칠 수 있으므로, 강진만의 일대 주변해역 식물플랑크톤의 현존량 및 군집구조로 이들 영향을 조사하였다. (중략)

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.4
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• pp.390-396
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• 2004

A double-inlet pulse tube refrigerator was fabricated as a U-shape with $\Phi$19.0 mm${\times}$125 mm regenerator packed by #200 stainless steel mesh and $\Phi$12.7 mm${\times}$125 mm pulse tube. A pressure sensor was installed at the inlet of the regenerator and a differential pressure sensor was installed across the bypass. Amplitude of the pulsating pressure was independent of the opening of the orifice and the bypass valves. Helium flow through the orifice and the bypass was calculated based on the measured pressure. Energy loss through the orifice and the bypass was evaluated with the measured pressure and the calculated helium flow rate. The energy loss, which is equivalent to the refrigeration capacity at the cold end of the ideal pulse tube refrigerator, was mainly generated through the orifice. It was proportional to the opening of the orifice valve, but the real refrigerator displayed the best performance at the optimized opening of the orifice valve. This optimized performance of the tested pulse tube refrigerator can be explained by additional refrigeration losses. As an example, the shuttle heat transfer loss of the pulse tube was calculated from the measured experimental data.

• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.3
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• pp.65-72
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• 2015

In present study, a supersonic inlet for dual mode ramjets or RBCC/TBCC engines with a wide range of flight Mach numbers is designed. A conical variable inlet configuration is chosen for the inlet design. Geometric relations with angles of compression cones and conical shock waves are used for the design of the inlet configuration. The performance of the supersonic inlet is confirmed by the numerical analysis. The capture area ratio is maintained around 100% from Mach 3 to 8 conditions.

• Journal of Chest Surgery
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• v.35 no.2
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• pp.149-152
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• 2002

We report successful application of dual trachcobronchial stcnt to the diffuse tracheal stenosis. An one-month-old boy was transferred to the emergency room due to tachypnea and respiratory difficulty with COB retention. Preoperative computed tomography revealed pulmonary artery sling with diffuse tracheal stenosis. We found that the diameter of the both main bronchus was less than 3mm and the trachea was a complete ring. We divided the left pulmonary artery and implanted it to the main pulmonary artery under cardiopulmonary bypass. After that, tracheoplasty was performed with autologous pericardium. However, after the initial measures, CO2 retention and respiratory difficulty persisted due to the granulation tissue and dynamic obstruction of the airway ensued by the overlying pericardial flap. Therefore, we decided to apply a single tracheal stunt. After the insertion of tracheal stent, residual stenosis of the both main bronchus opening continued to cause respiratory difficulty Finally we applied dual tracheobronchial stent and resolved the airway obstruction.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2002.04a
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• pp.27-27
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• 2002

본 연구에서는 상용코드 FLUENT를 통한 수치모사 결과를 바탕으로 개발한 이중 원호익형의 성능상관식을 축류펌프의 설계에 적용하여 보았다. 일반적으로 익형의 설계는 크게 두 단계를 거치게 된다. 먼저 반경방향의 평형과 설계조건을 만족하는 임펠러와 디퓨저의 입구와 출구의 속도 삼각형을 얻고, 다음으로 적당한 익형을 선택하여 기하학적 형상을 결정하는 과정으로 이루어져 있다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.6
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• pp.586-595
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• 2010

An analytical study based on physical understandings and aero-thermodynamic theories was conducted to observe the performance characteristics and to derive the essential design parameters of dual ramjet(dual-combustion/dual-mode) propulsion for wide Mach number. The performances and operating limitations of the engines with two types combustors, such as constant pressure- and constant area- combustor, over various flight Mach numbers was investigated. Finally, the transition Mach number from ramjet to scramjet was carried out to optimize performance load balancing of ramjet and scramjet.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.6
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• pp.596-604
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• 2010

In order to investigate the operating conditions and major design parameters of a dual ramjet propulsion system, an theoretical analysis of ramjet and scramjet propulsion systems was performed. The performance characteristics of each engine are delivered by thermo-dynamical cycle analysis, considering loss effects in a real engine. The performance sensitivity analysis is conducted by investigating various performance parameters, such as an intake efficiency, combustor inlet Mach number, configuration of the combustor, fuel flow rate, and exhaust nozzle efficiency. Based on these analysis results, the processes of application to dual ramjet cycle engines are specified.

• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.1
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• pp.45-51
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• 2018

The generation mechanism of NAR is not yet understood. In the present study, an in-depth analysis of the computational results previously obtained by the authors is conducted to investigate the flow mechanism responsible for NAR. A theoretical analysis has also been performed to understand the gas dynamic features during transition from scramjet to ramjet mode. It is known that there exists a critical value of the fuel equivalence ratio at which the flow states at the inlet of isolator remain unchanged. An increase in the equivalence ratio over the critical value leads to a sudden change in the static pressure and the Mach number at the inlet of the isolator, which is responsible for the generation of NAR.