• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.5
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• pp.401-408
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• 2012

Volumetric mass transfer coefficient was measured with carbon dioxide and deionized water for the gas-liquid cocurrent slug flow in 2, 5 and 8 mm tubes. Measurement was repeated with and without a vertical section in an experimental setup and entrance effect was found greater for smaller tubes. Volumetric mass transfer coefficient in the vertical section was found generally a strong function of gas- and liquid-phase superficial velocities. 5 mm- and 8 mm-tube data are highly consistent each other but not with 2 mm tube.

• 한국HCI학회:학술대회논문집
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• 2006.02a
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• pp.660-665
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• 2006

본 논문에서는 유비쿼터스 컴퓨팅 구현에 있어서 중요 핵심 요소 기술인 실내에서의 사용자의 위치를 인식하면서 동시에 사용자를 식별하는 방법에 대해 제안하고자 한다. 제안된 사용자 식별 방법은 초음파 센서의 물체까지의 거리를 측정할 수 있는 특성에 기초하여 구성원의 키 높이의 다름을 주요한 식별 특성으로 이용하는 방법이다. 또한 사용자 식별을 수행하는 것과 동시에 식별된 사용자가 센서가 장착된 문을 통과하여 들어왔는지 나갔는지를 감지하는 출입 감지 방법도 제안한다. 기본적인 출입 감지 방법의 아이디어는 2개 초음파 센서의 물체 감지 순서를 이용하여 개발되었다. 제안된 방법의 성능 검증을 위해 1단계의 프로토타입을 만들었으며, 개발된 프로토타입을 이용하여 3명의 가족 구성원으로 이루어진 일반 가정집의 화장실에 장착하여 성능 실험을 실시하였다. 실험 결과 100%의 사용자 식별 성능 및 평균 98%의 출입 감지 성능을 얻었다.

• East Asian mathematical journal
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• v.31 no.4
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• pp.421-444
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• 2015

The study conducted a survey on mathematics teachers' perception about the mathematics curriculum and carried out a field survey of schools' compliance of the 2009 revised mathematics curriculum. The questionnaires were distributed to and collected from 36 mathematics teachers in 22 middle and high schools. According to the results of the study, it was found that most mathematics teachers had low interest in and did not feel the necessity and importance of revising the mathematic curriculum. This was because that the necessity and direction of the curriculum revision was not well understood by secondary school teachers, thanks to a hasty revamping. In addition, schools are organizing and operating their own educational programs with the focus on the college entrance exams, regardless of the guidelines of the current revised curriculum.

• Advances in aircraft and spacecraft science
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• v.5 no.4
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• pp.445-458
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• 2018

Turbulent airflow in channels of rectangular cross section with symmetric centerbodies is studied numerically. Shock wave configurations formed in the channel and in front of the entrance are examined. Solutions of the unsteady Reynolds-averaged Navier-Stokes equations are obtained with finite-volume solvers of second-order accuracy. The solutions demonstrate an expulsion/swallowing of the shocks with variations of the free-stream Mach number or angle of attack. Effects of the centerbody length and thickness on the shock wave stability and flow bifurcation are examined. Bands of the Mach number and angle of attack, in which there exist non-unique flow fields, are identified.

• Journal of Engineering Education Research
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• v.20 no.4
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• pp.51-60
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• 2017

The purpose of this research is to analyze the educational experiences of competent engineering students and finding the reason why they invest their time and efforts engaging in school activities. Five students with high GPA, high K-CESA scores and successful employment or entrance test scores, participated in the survey and the interview. In checking their responses, their activities' records were gathered from school DB. According to the modified framework based on the personal investment theory, the interviews, survey and DB records were analyzed on the sense of self, the social cultural environment, and pattern of behaviors in schools. The competent engineering students are able to manage themselves, in maintaining a good relationship with the collegiate, and in having high self-efficiency. They also tend to put effort into their studies and participate in inbound and outbound school activities. At the last part, freshmen foundation, relationship within college, students' activity related future career, economic stability during studies are suggested for supporting students in universities.

• Journal of Korean Neurosurgical Society
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• v.50 no.6
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• pp.517-519
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• 2011

Stent assisted coiling on intracranial broad neck aneurysm has been considered as an effective technique and has made the complex aneurysms amenable to coiling. However, stent navigation and application themselves often have the problems especially when the parent vessel angle (entrance between afferent and efferent vessel) is over 90 degrees. We report here a case of a ruptured broad neck basilar top aneurysm that was successfully coiled using two self-expandable stents (Enterprise and Neuroform) placed in a fashion of modified Y-configured stents with waffle cone technique.

• Journal of Power System Engineering
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• v.17 no.6
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• pp.136-141
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• 2013

This study introduces and analyzes the energy for heating and cooling system in region with volcano-stratigraphic. The thermodynamic properties of air through the air blower installed at the entrance of borehole are measured. It estimates the availability of underground air for heating and cooling system through experimental data and theoretical analysis. Based on our conclusion from these calculations we predict possibility of over 40kW steady and stable energy source from underground. Therefore this underground air can be utilized in region with volcano-stratigraphic.

• Proceedings of the KIEE Conference
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• 2000.07a
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• pp.276-278
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• 2000

In KwangYang steel works power system operation, the ON-LINE application of power system diagnosis technology is indispensable to not only power quality, but also stable operation and economical generation. In cases of stability constraint violation. stable power system operation is obstructed. Steel works power system is consist of 154kV transmission lines, and 345, 154, 22, and 6.6[KV] distributed lines, 5 numbers of substation, 17 units of generators. For this power system operation. loadflow program is developed. Database is tied with Windows GUI application, is designed, and is interfaced with this program. This program put up with loadflow solution of assembled MMI power system, and planed to diagnose of overloads or to imitate entrance, and isolation of equipment.

• Proceedings of the KIEE Conference
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• 1998.11c
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• pp.1054-1060
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• 1998

Previous counter-current flow limitation (CCFL) and critical heat flux (CHF) studies included investigations on the inlet entrance, inclined channel and gap effects for the most part. In this study, the local CHF correlation was presented to be used in the numerical analysis for the 3 dimensional hemispherical geometry. Also, first-principle analyses were performed to determine the maximum heat removal capability from the debris through the gap that may be formed during a core melt accident. The maximum heat removal capability by gap cooling can be applied in quantitatively assessing the severe accident management measures.

• Journal of The Korean Association For Science Education
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• v.15 no.4
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• pp.417-428
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• 1995

This study investigated Korean science teachers' concerns and needs regarding inquiry testing to cope with the innovation called College Scholastic Abilities Test(CSAT), which was officially first administered as the nation-wide college entrance exam in 1994. This study adopted Concerns Based Adoption Model(CBAM) as the theoretical framework developed by Hall et al. 60 high science teachers (30 physics, 20 earth science, 10 others) were involved for the main study in August, 1992. In general. science teachers demonstrated a concern profile similar to that of 'nonusers'. They showed high level of concerns on the 'information' and 'personal' stage, while low level of concerns on 'management' and 'consequence' stage. Science teachers expressed their strong needs for knowledge and support to facilitate inquiry teaching and testing, text books written in inquiry mode. It is recommended that in-service trainings be provided based on the concerns and needs of teachers for a better teacher training and successful implementation of the innovation.