• Journal of Korean Society for Geospatial Information Science
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• v.22 no.4
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• pp.3-11
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• 2014

Recently, rapid urbanization has necessitated continuous updates in digital map to provide the latest and accurate information for users. However, conventional aerial photogrammetry has some restrictions on periodic updates of small areas due to high cost, and as-built drawing also brings some problems with maintaining quality. Alternatively, this paper proposes a scheme for efficient and accurate update of digital map using point cloud data acquired by Terrestrial Laser Scanner (TLS). Initially, from the whole point cloud data, the building sides are extracted and projected onto a 2D image to trace out the 2D building footprints. In order to register the footprint extractions on the digital map, 2D Affine model is used. For Affine parameter estimation, the centroids of each footprint groups are randomly chosen and matched by means of a modified RANSAC algorithm. Based on proposed algorithm, the experimental results showed that it is possible to renew digital map using building footprint extracted from TLS data.

• Korean Journal of Environment and Ecology
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• v.19 no.3
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• pp.287-298
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• 2005

This study was carried out to offer the raw data on conservation of land and natural environment by constructing groups of indicators to objectively and rationally assess the sustainable natural ecosystem and present the direction for establishing and planning the environmental policy. There were selected that four assessment items were biotic, abiotic, qualitative, and functional factor. And there were extracted fifty-six indicators including density, total nitrogen, hemeroby degree, and goods production. As assessment items and indicators were over 0.6, the design of questionnaire showed no great problem. In the results of correlation analysis of assessment indicators, sociality and dominance was highly correlative in biotic factor, soil property and aspect in abiotic factor, naturalized and urbanized index in qualitative factor, and protection of landslide and soil erosion were too correlative. In the results of deciding the dimension by multidimensional scaling, as stress values were from 0.042 to 0.133, index of fit over 0.9, there no statistical problems. In case of X axis, biotic factor was structure, viewpoint in abiotic factor, composition in qualitative factor, and object in functional factor, and Y axis was shaped Into form, range, structure, and activity.

• The Journal of the Acoustical Society of Korea
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• v.21 no.8
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• pp.708-718
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• 2002

In this paper, the problems in identifying the noise sources by using the sound intensity technique are dealt with for the general radiated near-field from vibro-acoustic sources. For this purpose, a three-dimensional model structure resembling the engine room of a car or heavy equipment is considered. Similar to the practical situations, the model contains many mutually coherent and incoherent noise sources distributed on the complicated surfaces. The sources are located on the narrow, connected, reflecting planes constructed with rigid boxes, of which a small clearance exists between the whole box structure and the reflecting bottom. The acoustic boundary element method is employed to calculate the acoustic intensity at the near-field surfaces and interior spaces. The effects of relative source phases, frequencies, and locations are investigated, from which the results are illustrated by the contour map, vector plot, and energy streamlines. It is clearly observed that the application of sound intensity technique to the reactive or reverberant field, e.g., scanning over the upper engine room as is usually practiced, can yield the detection of fake sources. For the precise result for such a field, the field reactivity should be checked a priori and the proper effort should be directed to reduce or improve the reactivity of sound field.

• Journal of Broadcast Engineering
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• v.23 no.1
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• pp.45-52
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• 2018

The virtual reality (VR) cartoon is a format of VR contents that leverage the characteristics of webtoons that provides the simple story line and graphical storytelling tools to strategically surmount limitations of VR contents design. The VR cartoon enables people to experience the imaginary three-dimensional space in the webtoon as a real space by the transformation of webtoon contents through VR prototyping. The VR cartoon successfully presents focused environment where people can readily pay attention to the contents without notable motion sickness. People have been familiar with the storytelling strategy in the context of published cartoons and webtoons, likely we've understood the narrative of a movie through the continuous scenes projected in the screen. Indeed, it has been recognized as a popular toolset of communication, where visual images are sequentially delivered by replacing multiple planar spaces to tell a story narrative. While there are discrete panels with the time and space resolution in the graphical cartoons, people can distill a commit closure based on their past experiences. This is a typical "grammar" of the cartoon, which can be extrapolated to the VR cartoon that provides a seminal storytelling strategy. In this article, we review how the storytelling strategy in webtoons has been transformed into that in VR cartoons, and analyze the key components of VR cartoons. We envision that our research can potentially create keystones to produce variety of new VR contents by reflecting various narrative media including cartoon as a 'sequential art'.

• Information Systems Review
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• v.15 no.3
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• pp.71-87
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• 2013

Companies as well as the Korean government show growing attention to the Smart Work which is enabled by the ongoing development of information and communication technologies (ICTs). Smart Work can be regarded as an extended version of telecommuting or distance work and defined as "working efficiently and conveniently regardless of time and place utilizing ICTs." Smart Work currently puts its emphasis on the work and life balance by changing the ways of working. Despite its emphasis on work and life balance, it is expected the boundaries between work and nonwork would blur, work and nonwork boundaries may become more permeable, and role conflicts would occur more times than before. To find ways to enhance work and life balance while escaping from expected conflicts in the context of Smart Work, we investigate the work and nonwork boundary strengths and the factors affecting them. In the course, we consider asymmetries between the work and nonwork boundary strengths and bidirectional nature of work and nonwork permeability. We develop two research models having work and nonwork boundary strengths as respective dependent variables. We empirically found that work role identification and nonwork-to-work permeability had influences on the boundary strength at work and that work-to-nonwork permeability affected the boundary strength at nonwork. However, nonwork role identification did not show any significant influence on the boundary strength at nonwork.

• Tunnel and Underground Space
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• v.13 no.3
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• pp.187-195
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• 2003

This case study which is to make 2-Dimension earth's crust structures clearly is about the great boring-hole blasting to provide ground vibration source of the reflected wave research on the Korean Peninsula earth's crust structures research. For this study we've done blasting twice-500 ㎏/charge per delay, 1,000 ㎏/charge per delay, and the specifications of blasting are the following - dia.: 300 ㎜, boring-depth : 100m, besides, we used the explosives and electric detonators which have sufficient detonating velocity and very excellent safety, capacity of detonating, accurate delay time. We charged explosives into steel pipe with bulk type to avoid dead pressure by ground water. And then we tested about pipe airtight and blasting to certificate which has no problem by using on this study. In the results, we succeeded each blasting in Seosan, Youngdong. For the Peak Sum Vector(PSV) around the blasting at the main points, its real measured PSV is higher 180 % than estimated PSV with USBM. In this study we can't to be analysis of vibration velocity, but to be key providing vibration source.

• Journal of Educational Research in Mathematics
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• v.20 no.3
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• pp.305-322
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• 2010

The epistemological obstacles in the area learning of plane figure can be categorized into two types that is closely related to an attribute of measurement and is strongly connected with unit square. First, reasons for the obstacle related to an attribute of measurement are that 'area' is in conflict. with 'length' and the definition of 'plane figure' is not accordance with that of 'measurement'. Second, the causes of epistemological obstacles related to unit square are that unit square is not a basic unit to students and students have little understanding of the conception of the two dimensions. Thus, To overcome the obstacle related to an attribute of measurement, students must be able to distinguish between 'area' and 'length' through a variety of measurement activities. And, the definition of area needs to be redefined with the conception of measurement. Also, the textbook should make it possible to help students to induce the formula with the conception of 'array' and facilitate the application of formula in an integrated way. Meanwhile, To overcome obstacles related to unit square, authentic subject matter of real life and the various shapes of area need to be introduced in order for students to practice sufficient activities of each measure stage. Furthermore, teachers should seek for the pedagogical ways such as concrete manipulable activities to help them to grasp the continuous feature of the conception of area. Finally, it must be study on epistemological obstacles for good understanding. As present the cause and the teaching implication of epistemological obstacles through the research of epistemological obstacles, it must be solved.

• Journal of Broadcast Engineering
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• v.25 no.2
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• pp.166-175
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• 2020

Recently, application fields for processing and using digital image contents in various forms and types are rapidly increasing. Since image content is high value-added content, the intellectual property rights of this content must be protected in order to activate the production and use of the digital image content. In this paper, we propose a deep learning based watermark embedding and extraction network. The proposed method is to maximize the robustness of the watermark against malicious/non-malicious attacks while preserving the invisibility of the host image. This network consists of a preprocessing network that changes the watermark to have the same resolution as the host image, a watermark embedding network that embeds watermark data while maintaining the resolution of the host image by three-dimensionally concatenating the changed host image and the watermark information, and a watermark extraction network that reduces the resolution and extracts watermarks. This network verifies the invisibility and robustness of the proposed method by experimenting with various pixel value change attacks and geometric attacks against various watermark data and host images with various resolutions, and shows that this method is universal and practical.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.1591-1595
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• 2006

하천은 인간에게 있어 물을 공급하는 중요한 하나의 공급원인 동시에 재해를 발생시킴으로서 인간에게 큰 피해를 줄 수 있는 위험물로서 존재한다. 이러한 이면을 가진 하천은 하천 자체로는 하천의 특성이 변화하지 않으며, 인위적이나 자연적인 원인으로 변화하는 것이다. 특히 강도가 큰 강우가 발생하였을 때 하천의 특성은 크게 변화한다. 강우시 하천은 유출량 증가와 유사량의 시공간적인 변화로 인해 형상거동의 자기조절 기작을 통하여 유역밖으로 이들을 안전하게 배출시키는 기능을 발휘한다. 하천 합류부는 각기 다른 특성을 가진 두 흐름이 만나는 지점으로 흐름과 지형 둘 다 변화하며, 합류부 이후에는 그 이전과는 다른 특성을 나타낸다. 따라서 합류부는 하천의 흐름상에서 중요한 부분이라고 할 수 있다. 본 연구에서는 강릉에 위치한 경포천과 제 1지류인 위촌천이 합류하는 구간을 대상으로 하여 홍수시 첨두유량의 크기와 발생위치 및 홍수 모의기간에 따른 하상변동에 대해 연구하였다. 이를 위해 1차원 하상 변동 모형인 HEC-6를 이용하여 하상변동을 모의하고 그 결과를 실측 하상변동량과 비교분석하였다. 유입수문곡선에서 첨두유량의 발생위치는 전반부, 중앙부, 후반부로 구분하였고, 홍수모의 기간은 1년, 5년, 10년으로 하였으며 1년 이상의 수문곡선은 1년의 수문곡선을 모의 기간만큼 반복 발생시키는 것으로 하였다. 그 결과 하상변동은 홍수 모의기간, 유입수문곡선의 첨두유량 발생위치와 첨두유량의 크기에 따라 그 양상이 현저히 달라지는 것을 확인하였다. 유입유량 조건에서 동일수문곡선의 반복에 따른 모의기간 별 하상변동은 퇴적과 침식의 규모가 확대되는 형태로 나타나는 것을 알 수 있다. 미치는 시간축척의 영향을 파악하기 위해 $70{\sim}90$ 시간 동안 실험을 수행하였다. 세굴의 측정은 투명한 아크릴로 제작된 수제 내부에 CC카메라를 수제 전 후면 및 측면에 설치하여 월류수제의 세굴 발생을 실시간으로 측정하며 동시에 수제의 각 면에 각각 3개의 압력센서를 설치하여 압력분포를 측정함으로써, 월류수제 주변의 압력변화에 따른 세굴심의 실시간 변화를 비교할 수 있도록 하였다. 수심이 연중 $25{\sim}35m$를 유지하는 H호의 경우 간헐식 폭기장치를 가동하는 기간은 물론 그 외 기간에도 취수구의 심도를 표층 10m 이하로 유지 할 경우 전체 조류 유입량을 60% 이상 저감할 수 있을 것으로 조사되었다.심볼 및 색채 디자인 등의 작업이 수반되어야 하며, 이들을 고려한 인터넷용 GIS기본도를 신규 제작한다. 상습침수지구와 관련된 각종 GIS데이타와 각 기관이 보유하고 있는 공공정보 가운데 공간정보와 연계되어야 하는 자료를 인터넷 GIS를 이용하여 효율적으로 관리하기 위해서는 단계별 구축전략이 필요하다. 따라서 본 논문에서는 인터넷 GIS를 이용하여 상습침수구역관련 정보를 검색, 처리 및 분석할 수 있는 상습침수 구역 종합정보화 시스템을 구축토록 하였다.N, 항목에서 보 상류가 높게 나타났으나, 철거되지 않은 검전보나 안양대교보에 비해 그 차이가 크지 않은 것으로 나타났다.의 기상변화가 자발성 기흉 발생에 영향을 미친다고 추론할 수 있었다. 향후 본 연구에서 추론된 기상변화와 기흉 발생과의 인과관계를 확인하고 좀 더 구체화하기 위한 연구가 필요할 것이다.게 이루어질 수 있을 것으로 기대된다.는 초과수익률이 상승하

• Resources Recycling
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• v.19 no.3
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• pp.62-70
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• 2010

As the demand for paper continues to grow and the importance of recycled paper, white ledgar(WL) and old newspaper pulp(ONP), continuously increase. In addition, usage of recycled paper is essential in terms of forest conservation and environmental protection issues. However, optical and mechanical properties of recycled paper have some drawbacks than regular paper's properties that is indispensable. In order to complement these problems of recycled paper, precipitated calcium carbonate (PCC) was synthesized by the In-situ process with a recycled pulp. Depending on the size of PCC is divided into 2 types, $0.01{\mu}m{\sim}0.09{\mu}m$ colloid type ultra-fine particle and $0.1{\mu}m{\sim}0.9{\mu}m$ cubic type particles. In this study, we analyze how the different shape and size of precipitated calcium carbonate affects in the optical and mechanical properties of the recycled paper used as a filler. Furthermore, we mixed with chemical pulp for overcome reduce of mechanical properties, without using other chemicals, when we use PCC as a filler. The results has the possibility to meet in GR excellent recycling certification mark, standard was proposed.