• 한국연소학회:학술대회논문집
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• 2002.06a
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• pp.133-139
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• 2002

The lean premixed technique has been proven very efficient in reducing NOx emissions from gas turbine combustors. However combustion instability is susceptible to occur in lean premixed combustor. So laboratory-scale dump combustor was used to understanding the underlying mechanisms causing combustion instabilities. In this study, tests were conducted at atmospheric pressure and inlet air was up to $360^{\circ}C$ with natural gas. The observed instability was a longitudinal mode with a frequency of ${\sim}341.8Hz$. At selected unstable conditions, phase-resolved OH chemiluminescence images were captured to investigate flame structure with various equivalence ratio. Combustion instability was observed to occur at higher value of equivalence ratio(>0.69). This study was performed to investigate the effects of equivalence ratio and fuel split measuring NOx and acoustic wave. The results reveal the effect of fuel-air unmixedness on lean premixed combustor.

• Proceedings of the Korea Contents Association Conference
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• 2011.05a
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• pp.155-156
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• 2011

기존의 디스플레이는 2차원적인 평면 이미지만을 제공하고 있으며, 3차원 이미지를 제공하기 위해서는 추가적인 장비를 설치해야 한다. 본 논문에서는 일반적으로 널리 쓰이는 LCD 디스플레이 내부에 3차원 입체적인 이미지를 제공하는 방법을 제시하고자 한다. 이를 위해 사용자의 위치를 추적할 때 적외선 카메라를 사용함으로써 사용자는 별도의 장비를 사용하지 않아도 된다. u-City 환경에서 이와 같은 방법으로 GIS 정보가 LCD 디스플레이 내부에 입체적인 형태로 보다 효과적으로 보여진다.

• Proceedings of KOSOMES biannual meeting
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• 2006.11a
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• pp.155-158
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• 2006

한국 남해안 거제도 앞바다에 투하된 인공용승구조물에 대한 유통 변화를 파악하기 위해 ADCP(Acoustic Doppler Current Profiler)를 선박에 장착하여 정선관측을 실시하였다. 관측결과 구조물 투하전과 후의 유통비교를 보면 구조물 주변역에서 표층에서부터 수심 $30\sim40m$까지의 충과 그 이심까지의 흐름이 다르게 나타났다. 또한 구조물 주변역에서 연직유동성분의 흐름이 구조물 투하 전에는 하강류의 분포가 많이 나타났으나 구조물 투하 후에는 상승류의 성분이 많이 나타남을 알 수 있었다.

• Journal of the Korean Institute of Landscape Architecture
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• v.18 no.4
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• pp.29-44
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• 1991

The purpose of this study is to investigate the maximum rate of daily users and the turnover rate of parks in Korea. Median calculation, percentile analysis, and regression analysis methods were adopted for the investigation of the maximum rate of daily users. The maximum level, adaptable level and current dispersion of each index were analyzed. The results are summarized as follows. 1) It is location, kinds of facility, and purpose of visiting that mainly affect the concentration pattern of the number of park users. 2) Parks are devided into such three types as common urban park, royal tomb park, and large amusement park. 3) Spring is the peak season in all parks. 4) The maximum daily rates of the three types of parks are 0.92%, 1.86%, 1.18% respectively and the turnover rates are 18%, 54%, 63% respectively. 5) The results of this study show the necessity of the revision of the existing maximum daily rate and turnover rate.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.5A
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• pp.394-401
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• 2007

MIMO transmission systems can have various transmission modes, which result from the various combinations of the antenna diversity with spatial multiplexing. In this paper, we find the optimal mode to maximize the capacity with the BER constraint and the optimal selection (diversity transmission or spatial multiplexing transmission) for transmission of each transmission antenna, if necessary. The computer simulation results show that the proposed scheme has more capacity than the conventional scheme.

• Journal of Fisheries and Marine Sciences Education
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• v.23 no.2
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• pp.162-181
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• 2011

The purpose of this study was to reveal controversial issues on Stages of Concern(SoC), which is one of the dimensions of Concerns Based Adoption Model(CBAM). To achieve the purpose, documental analysis was employed. The theoretical framework to analyze literature consisted of three categories including stages, measurements, and applications. Based on the framework, controversial issues on SoC were discussed regarding arguments of CBAM developers and critics. The researchers of this study suggested their own opinions on the issues after thorough examination of CBAM developer's arguments and oppositions against them. Finally, suggestions for further studies on issues of SoC and studies measuring SoC were made.

• Journal of Fisheries and Marine Sciences Education
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• v.25 no.2
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• pp.321-340
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• 2013

The purpose of this study was to investigate elementary school teachers'concern and implementation of differentiated instruction of mathematics. To achieve the purpose, this study applied measurements of CBAM, including Stages of Concern Questionnaire and Innovation Configurations Checklist, to 133 elementary school teachers. The results indicated that most teachers were in awareness stage, which meant they had little concern on differentiated mathematics instruction. As well as, analysis on innovation configurations revealed that b and c variation, each referred to fidelity to and deviance from national curriculum standard relatively, were dominant in their instruction. Based on the results, the study suggested implications on future policies and teacher training for differentiated mathematics instruction.

• Journal of Korean Society of Rural Planning
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• v.15 no.2
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• pp.59-68
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• 2009

Nowadays, local governments have been developing an image to represent their regions' identity. These characters contain unlimited capabilities of utilization and advertising effect that adds to their high value. However, we must consider how effectively the image helps in representing its region because some characters have been produced upon timely basis without consistent long-term planning. This study is to investigate the image and motif of the local government characters from the consumer's perspective. The results are as follows: 1)The images employed by the local governments are not highly preferred and most regions select motifs from their local agricultural products and native plants. 2)The variables that affect the character of the local governments are such as beauty, identity, etc. In conclusion, in order to maximize the local government image, one must improve the design concepts, encourage advertisement of regional festivities and travel commercialization, and advocate the identity and beauty of the local area to the residents and other regional people.

• Journal of the Korean Solar Energy Society
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• v.31 no.3
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• pp.57-66
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• 2011

A Photovoltaic/Thermal(PVT) solar system consists of PV module and thermal absorber plate which convert the absorbed solar radiation into electricity and heat. Meaningful researches and development (R&D) on the PVT technologies have been performed since the 1970s. This paper presents a review of the previous works covering the various types of PVT and their performance analysis in terms of electrical and thermal efficiency. This review compares electrical and thermal efficiency of the different types of PVT collectors and analyzes the parameters affecting PVT performance. Based on the literature review, box channel type PVT with unglazed, or flat plate PVT with glazed have the highest efficiency among them. From the literature review, R&D should be carried out aiming at improving their overall electrical and thermal efficiency, cutting down the cost, and making them more competitive in the energy consumption market.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.05a
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• pp.35-38
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• 2004

In general, tube drawing process is composed of two steps, so called first drawing and second drawing. Drawing cracks are mainly occurred during the 2nd drawing process due to the improper drawing process. In order to analyze the reduction distribution in successive two-step drawing process, tube drawing process was simulated by finite element method. From the finite element analysis, the balance between first and second reduction is proved to be important factor to prevent drawing cracks. Hence the numerical expression was developed for tube drawing process to distribute even strain and criteria curves that can predict the safe drawing region were also proposed using this numerical formula.