• Journal of Advanced Marine Engineering and Technology
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• v.40 no.9
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• pp.799-804
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• 2016

Broadband powerline communication (BPLC) uses distribution lines as a medium for achieving effective bidirectional data communication along with electric current flow. As the material characteristics of power lines are not good at the communication channel, the development of power line communication (PLC) systems for internet, voice, and data services requires measurement-based models of the transfer characteristics of the network suitable for performance analysis by simulation. In this paper, an analytic model describing a complex transfer function is presented to obtain the attenuation and path parameters for a multipath power line model. The calculated results demonstrated frequency-selective fading in multipath channels and signal attenuation with frequency, and were in good agreement with the experimental results. Inductive coupling units are used as couplers for coupling the signal to the power line to avoid physical connections to the distribution line. The inductance of the ferrite core, which depends on the frequency, determines the cut-off frequency of the inductive coupler. Coupling loss can be minimized by increasing the number of windings around the coupler. Coupling efficiency was improved by more than 6 dB with three windings compared to the results obtained with one winding.

• Journal of the Korea Concrete Institute
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• v.27 no.6
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• pp.615-623
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• 2015

The previous strut-and-tie models (STMs) to evaluate the shear strength of squat shear walls with aspect ratio less than 2.0 do not consider the axial load transfer of concrete strut and individual shear transfer contribution of horizontal and vertical shear reinforcing bars in the web. To overcome the limitation of the existing models, a simple STM was established based on the crack band theory of concrete fracture mechanics. The equivalent effective width of concrete strut having a stress relief strip was determined from the neutral axis depth and effective factor of concrete strength. The shear transfer mechanism of shear reinforcement at the extended crack band zone was calculated from an internally statically indeterminate truss system. The shear transfer capacity of concrete strut and shear reinforcement was then driven using the energy equilibrium in the stress relief strip and crack band zone. The shear strength predictions of squat shear walls evaluated from the current models are in better agreement with 150 test results than those determined from STMs proposed by Siao and Hwang et al. Furthermore, the proposed STM gives consistent agreement with the observed trend of the shear strength of shear walls against different parameters.

• The Journal of Korean Institute for Practical Engineering Education
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• v.2 no.2
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• pp.30-35
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• 2010

This paper proposes several methods for effective teaching of programing language(especially C). The programing languages are very important and basic subjects in the Department of Computer Engineering and Science. Many students have some difficulty in learning the programming languages. So, we will suggest several effective methods for effective teaching of programming languages. First, in order to understand the programming language effectively, we need to teach some basic computer architecture and operation principles of computer program to students. Second, it is better to teach many example-based programing skills instead of conventional grammar teaching. Third, if we teach the memory status(memory allocation/release) during the program operation, it will be much better to understand the pointer variables and memory problems. Fourth, let's improve the programming skills through effective homework assignments and experiments. Fifth, let students be guided so that they do programing by themselves. Finally, we can maximize the programming skill through the final termproject.

• Journal of Korea Water Resources Association
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• v.42 no.11
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• pp.1005-1015
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• 2009

Saltwater intrusion in coastal aquifer was investigated using a laboratory model. Salt-wedge profiles were reproduced in a porous media tank 140 cm long, 70 cm high, and 10 cm wide. The experiments were performed with various conditions of porous media hydraulic conductivity, salinity, and ground surface slope to assess relationships on salt wedge location and inclination. Salt-wedge profiles induced by saltwater intrusion were observed in porous media equilibrium state, and compared with previously derived formulas of the Glover (1959), Henry (1959) and Strack (1976). It was found that salt-wedge shape and formations were affected by the water level ratio ($H_F/H_S$) due to high hydraulic conductivity, saltwater salinity and ground surface slope. High $H_F/H_S$ of porous media having high hydraulic conductivity shifted the saltwater interface toward the saltwater reservoir. Increasing surface slope of the porous media caused the salt-wedge profile inclination to decrease. Saltwater salinity also contributed to the location of saltwater interface, yet the impact was not more significant than hydraulic conductivity.

• (The) Research of the performance art and culture
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• no.22
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• pp.123-155
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• 2011

This study aims to closely read Kim Jong-il's "About Stage Drama Arts" and disclose the new reality as evaluated by him. The study took the method by which to compare Kim Jong-il's theory on drama and North Korea's drama theory in the 1950s, and the findings of this study revealed that it was irrational to grant the adjective "new" to Kim Jong-il's drama theory. This is because tradition inheritance and newness cross each other. First, his tradition inheritance aspect was found in his playwriting method. In playwriting method, Kim Jong-il's argument about characters and language is an extension of the 1950s drama theory, and his theory on JongZa(seeds) is the transformation of the concept proposed in the 1950s. Also, the expression means of dramas and drama arts is dialogue, and his guideline to focus on the art of conversation rather than on acting is interpreted to be a reduced concept of drama arts, compared with the 1950s drama theory. On the other hand, his newness aspect can be clearly discovered in the materialization of stage. The fixed stage background, without dark change, shifts to another situation as it is, and this stage setting is clearly distinguished from the previous stage setting. The attempt is worth highly evaluating to allow the stage to reflect actors' emotional flows and let them act. Also, the attempt is distinctively distinguished from previous drama theories to allow the chorus' positive involvement in dramas so as to directly deliver characters' emotions to the audience and to trigger the audience' response as intended by creators. From the perspectives of drama evaluation, Kim Jong-il's theory and practice regarding stage and music is understood to maximize the audio-visual effects. Therefore, Kim Jeong-il's drama theory, as he argues, is not a completely new theory, but a transformational inheritance of existing drama theories, and a creation theory with focus on expansion of spectacles.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.991-995
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• 2005

본 연구에서는 1차원 이송-분산 과정을 연구하고 전단류 흐름 및 분산거동에 있어 Taylor 이론의 핵심이라 할 수 있는 '종방향 이송과 횡방향 확산의 균형'을 기본 개념으로 하여, 이송과 확산을 분리하여 이 두 과정이 순차적으로 발생한다는 가정에 의거한 순차혼합모형을 제시하였다. 본 모형에서는 가상의 하천을 여러 개의 행과 종방향 거리를 길이가 일정한 구획으로 나누어 연속적인 분산과정을 이산적인 형태로 나타낼 수 있게 하고, 횡방향 유속분포에 따라 각 행에 각기 다른 유속을 할당한다. 오염물질은 하폭방향 선오염원으로 원점에 순간주입되며, 주어진 혼합시간 $t_m$ 동안 각 행의 오염물질들이 각자에 할당된 유속을 따라 진행하고 진행이 끝난 후 횡방향 확산이 순간적으로 이루어진다. 횡방향 확산은 횡방향으로 완전하게 일어남을 가정하여, 횡방향 확산이 끝나면 각 열에서의 농도 평균값이 할당된다. 이러한 혼합시간 $t_m$ 동안의 순차적인 이송-확산 과정이 반복되면서 오염물질의 분산이 일어나며, 농도 분포 그래프를 그릴 수 있게 된다. 순차혼합모형을 가상의 직선하천에 적용하여 종분산계수를 유도하였는데, 본 연구에서 유도된 종분산계순식은 Fischer.가 제안한 식과 유사한 형태로 나타남을 알 수 있었다. 본 모형에서 계산된 농도분포 곡선을 해석해와 비교한 결과,두 곡선이 적절히 일치함을 확인할 수 있었으며 해석해와의 비교를 통해 종분산계수 K가 혼합시간 $t_m$과 선형관계임을 확인할 수 있었다. 수심대하폭비에 따라 각기 다른 유속분포에 적용하여 종분산계수 K가 유속편차강도의 제곱에 비례관계에 있음이 밝힐 수 있었다. 수압은 $4.69kg/cm^2$으로 나타났다. 밸브 개폐도가 $100\%$일 때가 밸브를 $60\%$와 $80\%$ 개폐시켰을 때보다 $0.3kg/cm^2,\;0.29kg/cm^2$ 낮게 나타나 밸브를 전체 개방 했을 때 관로내의 수압이 상수설계기준에 적합한 수압을 유지함을 알 수 있다. 상수관로 설계 기준에서는 관로내 수압을 $1.5\~4.0kg/cm^2$으로 나타내고 있는데 $6kg/cm^2$보다 과수압을 나타내는 경우가 $100\%$로 밸브를 개방하였을 때보다 $60\%,\;80\%$ 개방하였을 때가 더 빈번히 발생하고 있으므로 대상지역의 밸브 개폐는 $100\%$ 개방하는 것이 선계기준에 적합한 것으로 나타났다. 밸브 개폐에 따른 수압 변화를 모의한 결과 밸브 개폐도를 적절히 유지하여 필요수량의 확보 및 누수방지대책에 활용할 수 있을 것으로 판단된다.8R(mm)(r^2=0.84)$로 지수적으로 증가하는 경향을 나타내었다. 유거수량은 토성별로 양토를 1.0으로 기준할 때 사양토가 0.86으로 가장 작았고, 식양토 1.09, 식토 1.15로 평가되어 침투수에 비해 토성별 차이가 크게 나타났다. 이는 토성이 세립질일 수록 유거수의 저항이 작기 때문으로 생각된다. 경사에 따라서는 경사도가 증가할수록 증가하였으며 $10\% 경사일 때를 기준으로 $Ro(mm)=Ro_{10}{\times}0.797{\times}e^{-0.021s(\%)}$로

• The Journal of the Korea Contents Association
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• v.14 no.8
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• pp.122-129
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• 2014

The idea of global cities were widespread in the 20th century, but now in the 21st century the paradigm has changed into creative cities. They are trying to develop the creative contents in which economy and culture are connected to promote their global competitiveness. This thesis focuses on the three main points represented in the projects of publishing journals of Namyangju city. Firstly, the project held 'community-based lectures of humanities,' and 'literary contest' to induce participation of the citizens. The results of the events, however, were not successful because of the narrow extent of creative groups of the city and not enough campaign of the city. Secondly, there was the education of citizens to promote their participation, as they are so much the main parts of publishing journals that theory and practice of reporting on their own is essential. Thirdly, the project committee established citizen publishing committee and encouraged them to do their parts at each department. As a result, citizens succeeded in building cultural infrastructure for shaping the creative city and had the initiative to publish journals about masters, masterpieces, and attractions in Namyangju city. The city and the citizens should practice the culture contents projects in both sides' cooperation.

• Archives of design research
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• v.20 no.1 s.69
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• pp.167-176
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• 2007

As much time is being spent with the family at weekends by the development of leisure culture, many people have begun to enjoy camping in the field. While many people use pensions or camping cars, many families or groups of friends go on camping in the summer holiday season. Although the tent design in this country has gradually been developed, it is not as developed as overseas designs with unique design characteristics according to climate, cultural behavior and colors. In this research, the American and Korea tent designs are compared in terms of color and frame. The differences are analyzed and a direction for tent designs appropriate for Korea in terms of size, area, ease of carriage and installation is proposed through theoretical data and idea sketches. The frame weight has been minimized and the durability increased for the ease of carriage and installation. The style and number of windows have been increased in order to provide a comfortable space by understanding the influx of airflow and the size of the tent has also been increased to provide extra space for storage. The information on the overseas and domestic tent design trends led to a color comparison and the extraction of images of language. The tent based on the new design is currently being mass-produced in China following 3 months of preparation including sample making and testing.

• Journal of the Economic Geographical Society of Korea
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• v.18 no.1
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• pp.115-135
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• 2015

In the glocalization a common phenomenon of several nations reveals knowledge innovation and growth by the important subject of region and state and is studied at theory and practice. the successful cases of regional development in an advanced country have leading innovation through regional innovation system and cluster. therefore we are necessary to analyse how the knowledge spillovers in innovative cluster as the reduced model of regional innovation system guide firm innovation and region growth. this article reviews theories and empirical studies of the knowledge spillovers in the regional innovation system and innovative cluster of innovative geography and proposes a new research issues for further explorations of the knowledge spillovers. Previous studies assist that knowledge spillovers exist in knowledge-based industries of specific local area and local innovation accomplishes through pure knowledge spillover. but limits of these studies include narrow region and technological area, few analytical variable and exclusion of rent knowledge spillover. therefore new research topics related with that exemplifies geographical dimension(concentration and decentralization), technological dimension(knowledge based industry), category of analytic variables(previous indicators, time, and social capital), conceptualization(appropriation means, markets for technology) etc.

• Archives of design research
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• v.19 no.5 s.67
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• pp.85-94
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• 2006

In the 2000s, character animation technique is used at domestic TV character animation ads of diverse items displaying new character patterns and expression techniques of a high level. This study intends to identify the characteristics of TV character animation ads based ell character aesthetic theory and advertising rhetoric theory, and based on these findings, analyze trend and stream of expression in TV character animation ads by examining and classifying advertisements released in the past four years by items, character patterns and expression techniques. The results showed that TV character animation ads have been concentrated on confectionery, beverages and foods in the past, but the items have been diversified through the years. With reference to character patterns, personal and animal characters had made the main pattern, but recently product, virtual and composite characters are on the increase. In expression techniques, cell animation technique was found to be the most frequently used technique, which was followed by full-3D, cell and live action, cell and 3D and the clay animation technique. A trend like this suggests that TV character animation advertising items will continue to increase in line with the participation level of targets. In the meantime, personal and animal characters will continue to make the leading character pattern, while virtual and composite character patterns emerge in new forms. In expression techniques, live action combined with 30 technique and techniques using new expression materials will appear with cell animation technique as a central figure. As a whole, Korean character animation advertisement is expected to keep on growing to a new dimension in the aspect of items, character patterns and expression technique.