• 한국컴퓨터정보학회논문지
• /
• 제5권2호
• /
• pp.7-13
• /
• 2000

객체지향 프로그램의 테스트 적합성 기준에 근거한 구현기반 클래스 테스팅 방법을 제안한다. 데이터 멤버간 종속성과 테스트 데이터 적합성에 대한 공리들을 고려하여 흐름 그래프 기반 테스팅 기준을 만족시키는 테스트 케이스인 메소드의 시퀀스를 생성시킨다. 파생 클래스 테스팅을 위해서 유산관계와 실험을 통해 테스트 비용 절감을 검증한 부모 클래스에 대한 테스팅 정보의 재사용성을 고려한다.

• 한국생산제조학회지
• /
• 제24권4호
• /
• pp.394-399
• /
• 2015

Because flow uniformity affects the life cycle and performance of the catalyst, it is an important design factor for selective catalytic reduction (SCR) systems. We examined how the diffuser angle and the area ratio of the inlet of the SCR reactor to the front of the catalyst affect flow uniformity. For the numerical analysis, we used STAR-CCM+, a common CFD software program. Analysis results showed that the larger the area ratio was, the less the flow uniformity was, and that the longer the diffuser length was, the greater the flow uniformity was. When the area ratio was greater than 1:5, the flow uniformity appeared very similar at the front of the catalyst. As a result, the spread time of the exhaust gas increased and the flow velocity decreased.

• 디지털융복합연구
• /
• 제16권8호
• /
• pp.373-380
• /
• 2018

본 연구는 초등학교의 표현활동수업에서의 교수행동유형이 몰입 및 유능감에 미치는 영향을 알아보는데 목적이 있다. 본 연구에서는 B광역시 소재 초등학생을 모집단으로 선정하였다. 연구 설계에 준하여 비확률 표본추출방법 중의 하나인 편의표본추출법을 사용하여 표본을 추출하였다. 총 300부를 배포하여 280부를 회수하였고 응답이 불성실하거나 적합하지 않은 자료를 제외하고 216부를 최종분석에 사용하였다. 자료처리는 Window용 SPSS 통계 Package 22.0 Version을 이용하여 빈도분석, 탐색적 요인분석, 신뢰도 분석, 상관관계 분석 및 다중회귀분석을 실시하였다. 결과는 다음과 같다. 첫째, 교수행동유형의 하위요인인 지시형, 권위형, 민주형, 보상형 모두 몰입에 유의한 것으로 나타났다. 둘째, 교수행동유형의 하위요인인 민주형, 보상형은 유능감에 유의한 것으로 나타났으나, 지시형, 권위형은 유의하지 않은 것으로 나타났다. 셋째, 몰입은 유능감에 유의한 것으로 나타났다.

• 한국물환경학회지
• /
• 제26권2호
• /
• pp.208-214
• /
• 2010

This study aimed at the introduction of desktop method for assessment of environmental flows developed by International Water Management Institute (IWMI) recently and its application to Geum river basin. This scheme simulated the influence on aquatic ecosystem caused by watershed development and in turn the decrease of water quantity keeping the river's own flow regime. It was found to be as very effective method although it had simple structure. Flow duration curves for different environmental classes at Sutong and Gongjoo sites were estimated according to the natural conditional scenario of Geum river basin and the results were relatively compared well with the previous studies. The behaviors of monthly average runoff time series of both sites showed the level of A class. The results of this study would provide the fundamental data to establish the future plans of monitoring or management for aquatic ecosystem of Geum river basin.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(II)
• /
• pp.1174-1177
• /
• 1987

The design of flow control protocols for integrared networks with complete voice traffic on the data link level is investigated. The class of admissible flow control policies analyzed maximized the average data link throughput subject to an average system time delay constraints a finite intervals (O,s). In particular, it is shown that the optimum control law is bang-bang (window flow mechanism). The window size L can be analytically derived from maximum tolerated time delay T, the input arrival C of the queueing system, the duration of the time interval S, the initial number of packets in the queue.

• 한국유체기계학회 논문집
• /
• 제14권2호
• /
• pp.41-46
• /
• 2011

This study investigated the changes in performance and operating characteristics of an F-class gas turbine according to the change of working fluid from air to carbon dioxide. The revised gas turbine is the topping cycle of the semi-closed oxy-fuel combustion combined cycle. With the same turbine inlet temperature, the $CO_2$ gas turbine is expected to produce about 85% more power. The main contributor is the greater compressor mass flow and the added oxygen flow for the combustion. Compressor pressure ratio increases about 50%. However, the gas turbine efficiency reduces about 10 %. Modulation of inlet guide vane to reduce the compressor inlet mass flow, the major purpose of which is to reduce the compressor inlet Mach number, was also performed.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1996년도 하계학술대회 논문집 C
• /
• pp.1888-1891
• /
• 1996

Recently, FLIC(Fluid In Cell) method has been widely used for the compressible. flow computation. A program which adopts the FLIC method and can analyze the flow conditions with arc in the interrupter was developed in our team. It was applied to the 800kV class gab circuit breaker for flow conditions with arc, and the results are presented and discussed in this paper.

• 유체기계공업학회:학술대회논문집
• /
• 유체기계공업학회 2004년도 유체기계 연구개발 발표회 논문집
• /
• pp.445-451
• /
• 2004

Four design candidates for a 1.4MW class partial admission turbine have been chosen from a Preliminary design process. Their performance were estimated through the 3-D numerical analyses using a frozen rotor method. In order to select the optimum design, each flow analysis result was compared with others. Flow characteristics in the passages and some types of losses induced by shocks and wakes were found from calculation results. Based on these calculations, a new rotor blade was redesigned and compared with previous one through flow analysis.

• Journal of information and communication convergence engineering
• /
• 제18권4호
• /
• pp.239-244
• /
• 2020

This study analyzed the influencing factors of learning engagement and teaching presence in online programming practice classes. The subjects of this study were students enrolled in an industrial specialized high school, who practiced creating Arduino circuits and programming using a web-based virtual practice tool called Tinkercad. This research adopted a tool that can measure task value, learning flow, learning engagement, and teaching presence. Based on this analysis, learning flow had a mediating effect between task value and online learning engagement, as well as between task value and teaching presence. Increasing learning engagement in online classes requires sensitizing the learners about task value, using hands-on platforms available online, and expanding interaction with instructors to increase learning flow of students. Furthermore, using virtual hands-on tools in online programming classes is relevant in increasing learning engagement. Future research tasks include: confirming the effectiveness of online learning engagement and teaching presence through pre- and post-tests, and conducting research on various practical subjects.

• 한국초전도ㆍ저온공학회논문지
• /
• 제15권3호
• /
• pp.35-39
• /
• 2013

In this paper, we present test results of developed 100 W class linear compressor for Stirling-type pulse tube refrigerator. The fabricated linear compressor has dual-opposed configuration, free piston and moving magnet type linear motor. Power transfer, efficiency and required pressure waveform are predicted with designed and measured specifications. In experiments, room temperature test with flow impedance is conducted to evaluate performance of developed linear compressor. Flow impedance is loaded to compressor with metering valve for flow resistance, inertance tube for flow inertance and buffer volumes for flow compliance. Several operating parameters such as input voltage, current, piston displacement and pressure wave are measured for various operating frequency and fixed input current level. Behaviors of dynamics and performance of linear compressor as varying flow impedance are discussed with measured experimental results. The developed linear compressor shows 124 W of input power, 86 % of motor efficiency and 60 % of compressor efficiency at its resonant operating condition.