• Journal of Advanced Marine Engineering and Technology
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• 제29권2호
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• pp.154-160
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• 2005

The result of combustion experiment by using the methanol-gasoline blended fuel showed that the supplying pressure appeared the maximum pressure between equivalent rate 1.1 and 1.2. and the evaporation of the fuel has been known to have been greatly influenced by surrounding temperature and the combustion chamber temperature after being injected from the injector And it is confirmed that the rate of evaporation had been suddenly dropped according to the temperature in the combustion chamber though the injected foe) had been fully evaporated Such tendency has visibly appeared when the zone is leaner. and we recognize that the rich fuel supply is needed in the operation of cold operating.

• 영재교육연구
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• 제25권1호
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• pp.37-58
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• 2015

본 연구는 개념적 혼란이 지속되고 있는 융합교육의 특성을 규명하기 위하여 융합교육의 현장경험을 가진 교사 19명을 대상으로 델파이 연구를 수행하였다. 총 3차의 델파이 연구가 실시되었으며, 융합교육의 특성으로서 핵심요인과 기대효과를 도출하였다. 융합교육의 전제 조건인 핵심요인은 학습자의 다양한 질적 경험을 위해 교육내용과 교육방식의 개방적이고 융통적인 활용을 강조하는 '교육설계', 교사, 교사-동료 간, 교사-학습자 간의 관계 속에서 발휘되는 교사의 역량을 의미하는 '교사전문성', 다양한 교육주체의 심리적 지원을 통해 융합교육을 가능하도록 하는 '교육환경'으로 유형화되었다. 융합교육의 기대효과는 '학습자의 인지적 특성', '학습자의 정의적 특성', '교사 및 교육체제' 차원에서의 변화를 포함하였으며, 융합교육이 교육 본연의 가치를 실현하는 하나의 틀로서 인식되었다. 본 연구에서 융합교육은 다수의 일반적인 학습자를 대상으로 한 교육적 가치 실현을 지향하며, 다양한 교육내용과 교육방식을 적용하고 교사의 전문성을 비롯한 관련 교육주체의 심리적 요인이 중요한 핵심요인으로 다루어진다는 특성을 나타냈다. 연구의 결과는 융합교육의 실체를 다각적인 이해의 틀을 가지고 교육 현장의 맥락에서 확인하였다는 점에서 의의를 갖는다.

• 한국음향학회:학술대회논문집
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• 한국음향학회 1999년도 학술발표대회 논문집 제18권 2호
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• pp.325-328
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• 1999

The aim of this paper is to measure the duration of Japanese 'sokuon' [t/k] and 'haneron' [m/n] pronounced by Korean and Japanese. It is revealed in this study that gemination of the Japanese 'sokuon' in Korean pronunciation lasts 1.5 times longer than a single consonant, whereas it lasts 2 times longer in Japanese pronunciation. The difference between Korean and Japanese seems to show the difficulty of perceiving and learning a foreign rhythmic pattern non-existent in the leaner's language. The gemination of [s] phoneme lasts 2 times as long as a single consonant in both Korean and Japanese pronunciation. On average, the duration of Japanese 'sokuon' [t/k/s] is 1.7 times longer than a single consonant in Korean pronunciation, whereas 2 times longer in Japanese pronunciation. The pronunciation of Japanese 'haneruon' by either Korean or Japanese produces a similar result: 1) gemination lasts longer than a single consonant, 2) the duration of the single [m] is longer than that of the single [n]; 3) gemination of [n] is 3 times as long as a single [n], whereas gemination of [m] is 2 times as long as a single [m].

• 한국실내디자인학회논문집
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• 제25권6호
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• pp.15-22
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• 2016

Recent changes in the Korean education policies are promoting the advances in science and technology and cultivating people of convergence talent. STEAM (science, technology, engineering, art and math) educational program is Korean styled convergence program for creative competent human resources. Therefore, Therefore the aim of this study is developing convergence hand-on educational program coping with climate change for elementary school students. For development of the program, we investigated the curriculum of the elementary school about the climate change, and allocated in the creative learning standard frame. Also, we selected themes related the climate change in the curriculum and learning activity. For more effective program to build the convergence competency, we analyzed the program based on creative problem based learning process and 4 core competency(creativity, communication, convergence, caring) elements. In conclusion, the STEAM program needs to develop by school curriculum and leaner's ability. For elementary school students, the STEAM program consists with creative problem based learning process. And the convergence educational program would analyze by the creative PBL process and convergence competency elements. So, this developing program has brought the promotion of the creative convergence competent talented person for the future global environment.

• 한국자동차공학회논문집
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• 제19권1호
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• pp.1-8
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• 2011

In recent years, there has been an interest in early-injection diesel engines as it has the potential of achieving a more homogeneous and leaner mixture close to TDC compared to standard diesel engine. The more homogeneous mixture may result in reduced NOx and soot emissions and higher efficiency in homogeneous charge compression ignition engines. While earlier studies have shown that a reduction in NOx emissions from HCCI engine is possible, there are some significant problems including the control of ignition timing and combustion rate. In order to investigate the effect of EGR and hydrogen enriched gas on combustion characteristics and emissions, an experiments with single cylinder CRDi engine were carried out concerning the formation of various premixed charge, which can achieved by early injection, EGR and hydrogen enriched gas. EGR was not effective to further reduce NOx and PM emissions. It was found that NOx emissions were decreased with an introduction of hydrogen enriched gas and an adequate diesel fuel amount.

• 한국자동차공학회논문집
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• 제14권4호
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• pp.20-25
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• 2006

Recently, there has been an interest in premixed diesel engines as it has the potential of achieving a more homogeneous and leaner mixture close to TDC compared to conventional diesel engines. Early studies are shown that in a HCCI(Homogeneous Charge Compression Ignition) engine, the fuel injection timing and injection angle affects the mixture formations. Thus the purpose of this study was to investigate relationship of combustion and mixture formations according to injection timing and injection angle in a common rail direct injection type HCCI engine using a early injection method called the PCCI(Premixed Charge Compression Ignition). From this study, we found that the fuel. injection timing and injection angle affect the mixture formations and in turn affects combustion in the PCCI engine.

• 한국자동차공학회논문집
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• 제10권3호
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• pp.93-100
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• 2002

For natural gas and LPG fuel, measurements on the concentrations of individual exhaust hydrocarbon species have been made as a function of air-fuel ratio in a 2-liter four-cylinder engine using a gas chromatography. NMHC in addition to the species of HC, other emissions such as CO$_2$, CO and NOx were examined for natural gas and LPG at 1800rpm far two compression ratios (8.6 and 10.6). Fuel conversion efficiencies were also investigated together with emissions to study the effect of engine parameters on the combustion performances in gas engines especially under the lean bum conditions. It was found that CO$_2$ emission decreased with smaller C value of fuel, leaner mixture strength and the higher compression ratio. HC emissions from LPG engine consisted primarily of propane (larger 60%), ethylene and propylene, while main emissions from natural gas were mothane (larger than 60%), ethane, ethylene and propane on the average. The natural gas was proved to give the less ozone formation than LPG fuel. This was accomplished by reducing the emissions of propylene, which has relatively high MIR factor, and propane that originally has large portion of LPG. In addition, natural gas shows a benefit in other emissions (i.e. NMHC,NOx, CO$_2$and CO), SR and BSR values except fuel conversion efficiency.

• 한국자동차공학회논문집
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• 제14권3호
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• pp.1-9
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• 2006

Recently, there has been an interest in premixed diesel engines as it has the potential of achieving a more homogeneous and leaner mixture close to TDC compared to conventional diesel engines. Because this concept reduced NOx and smoke emissions simultaneously. Early studies are shown that in a HCCI(Homogeneous Charge Compression Ignition) engine, the fuel injection timing and intake air temperature affect the mixture formation. The purpose of this study is to investigate characteristics of combustion and mixture formation according to injection timing and intake air temperature in a common rail direct injection type HCCI engine using an early injection method called the PCCI(Premixed Charge Compression Ignition). From this study, we found that the fuel injection timing and intake air temperature affect the mixture formation and in turn affects combustion in the PCCI engine.

• Journal of Preventive Medicine and Public Health
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• 제12권1호
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• pp.24-30
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• 1979

This study was conducted to find out the most suitable weight-height index out of the $weight/height^{p}-type$ indices that could be used for the evaluation of nutritional status in an epidemiological survey and for the screening of the obesity. The subjects were chosen randomly, 2,182 males and 719 females from college students and office workers in Seoul districts. The 'best' power-type weight-height index for Korean men and women of all ages from 16 to 59 was found to be $weight/height^{1.54}$ for males and $weight/height^{1.42}$ for females. $Weight/height^2$ (Kaup index), however, was the best suited weight-height index for each age group of both sexes except that relative weight (weight/height) was considered to be desirable to apply for males of teen-aged and of over fifties and for females of over forties of age. Normal ranges of Kaup index values for males and females of each age group were presented in tables 5 and 6. These findings suggest that Koreans are generally leaner than other ethnic groups of the same sex and age.

• 컴퓨터교육학회논문지
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• 제8권3호
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• pp.91-100
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• 2005

대학교육에 있어서, 학습자 중심의 교육과정으로 개편하려는 노력이 이루어지고 있는데, 이러한 노력은 대학교육의 질을 제고하고 대학의 경쟁력과 학습자의 전문성을 향상시키기 위한 하나의 전략으로 평가된다. 가장 단순한 형태인 과목 중심의 운영 방식인 현재의 선택 방식을 개선한 SSC 교육과정을 제안하고 그 교육적 효과를 측정해보았다. 그 결과, SSC 교육과정을 이수한 학습자들의 학업성취도가 SC 교육과정을 이수한 학습자보다 높은 것으로 나타났다.