• Journal of The Geomorphological Association of Korea
• /
• v.18 no.4
• /
• pp.35-57
• /
• 2011

Minor erosional forms in the bedrock river, like potholes, are not just research subject for the professional geomorphologis. In addition, these features attract general public and make them understand the social contribution and importance of geomorphologic research activities. In this paper, the studies on bedrock minor forms in Korea was reviewed. For further researches, some of major erosional processes and minor forms in bedrock rivers were discussed in detail. Cavitation, plucking, hydro-wedging, and abrasion by passing sediment particles are the major processes to create the longitudinal or transverse minor forms like pothole, furrows, flutes, and runnels. Especially the definition of furrows and runnels are explained to prevent the confusion with pothole, weathering pits and grooves. To make a progress in research on bedrock minor forms the quantitative relationship between the variables should be studied. New techniques for scientific estimation of erosion rates and exposure ages of bedrock surfaces should be used in this field.

• Geophysics and Geophysical Exploration
• /
• v.19 no.1
• /
• pp.20-28
• /
• 2016

Recently many sinkholes have appeared in urban areas of Korea, threatening public safety. To predict the occurrence of sinkholes, it is necessary to investigate the existence of cavity under urban roads. Ground-penetrating radar (GPR) has been recognized as an effective means for detecting underground cavity in urban areas. In order to improve the understanding of the governing physical processes associated with GPR wave propagation, and interpret underground cavity effectively, a theoretical approach using numerical modeling is required. We have developed an algorithm employing a three-dimensional (3D) staggered-grid finite-difference time-domain (FDTD) method. This approach allows us to model the full electromagnetic wavefield associated with GPR surveys. We examined the GPR response for a simple cavity model, and the modeling results showed that our 3D FDTD modeling algorithm is useful to assess the underground cavity under urban roads.

• Bulletin of the Society of Naval Architects of Korea
• /
• v.27 no.4
• /
• pp.15-26
• /
• 1990

This paper describes a potential-baoed panel method formulated for the analysis cf a supercavitating two-dimensional symmetri strut. The method employs normal dipoles and sources distributed on the foil and cavity surfaces to represent the potential flow around the cavitating hydrofoil. The kinematic boundary condition on the wetted portion of the foil surface is satisfied by requiring that the total potential vanish in the fictitious inner flow region of the foil, and the dynamic boundary condition on the cavity surface is satisfied by requiring that the potential vary linearly, i.e., the tangential velocity be constant. Green's theorem then results in a potential-based integral equation rather than the usual velocity-based formulation of Hess & Smith type, With the singularities distributed on the exact hydrofoil surface, the pressure distributions are predicted with improved accuracy compared to those of the linearized lifting surface theory, especially near the leading edge. The theory then predicts the cavity shape and cavitation number for an assumed cavity length. To improve the accuracy, the sources and dipoles on the cavity surface are moved to the newly computed cavity surface, where the boundary conditions are satisfied again. This iteration process is repeated until the results are converged.

• Journal of the Korean earth science society
• /
• v.37 no.4
• /
• pp.243-268
• /
• 2016

The purpose of this study was to explore the effects of Cogenerative Dialogues embedded in a modeling-centered science learning and instruction on 7th grade female $students{\acute{i}}$ understanding of scientific models and modelling A total of 49 7th grade female students in two classrooms participated in a series of five modeling-centered science lessons, and 17 students volunteered to participate in this study. Participating students were divided into four groups, and two groups were randomly assigned to a treatment group who were asked to participate in Cogenerative Dialogues after each lesson, while the others, a control group, who did not. For data analysis, Upmeier and $Kr{\ddot{u}ger^{\prime}s$ framework was used to explore $participants{\acute{i}}$ understanding of model, and a revised $Baek{\acute{i}}s$ framework was used to examine $participants{\acute{i}}$ modeling process. Data analysis indicated that students who participated in Cogenerative Dialogues generally showed richer understanding of scientific models, as well as modeling, than the others who did not. This study suggests that Cogenerative Dialogues can be used as an educationally meaningful method for science educators to encourage students actively participate in a whole process of science instruction and learning, which assists them to increase their understanding not only of scientific models and modeling specifically but also of the nature and processes of scientific practice in general.

• The Journal of the Petrological Society of Korea
• /
• v.16 no.2 s.48
• /
• pp.47-58
• /
• 2007

This study examines the distribution of basement rocks in Gyochon-ri, Muan-eup, Muan-gun, Jeonnam where ground subsidence occurred in June 2005, and traces corrosion of limestone. Mica schist and rhyolite are distributed in the surface of the study area, but thick limestone layer with large and small caverns are distributed underground. A horizon of limestone with maximum width of 300 m and 4 km of length was found along the detour which is in the north of pound subsidence. Such identification of limestone presence would be very useful to predict potential ground subsidence. Limestone in this area was disturbed by fold and fault due to severe shearing deformation. Small caverns were frequently found in anticline part of folds formed in limestone layer. Schists with different thicknesses were intercalated in the limestone with shearing deformation and consist of sheet silicate minerals (chlorite and mica) and quartz. In sections of weathered specimen, it is shown that biotite of schist part was altered into chlorite and corrosion of calcite around the schist followed. This suggest that ground water permeated between intercalated sheet silicate minerals and corrosion of limestone began. And small caverns were generated where active corrosion occurred. This study suggests that because of many reasons (for instance, reclamation of the Bulmu reservior and excess pumping), cavern water level was lowered and cave sediments were removed, and it caused ground subsidence to occur.

• Proceedings of the Costume Culture Conference
• /
• 2003.04a
• /
• pp.42-44
• /
• 2003

'95년 하반기부터 시작된 경제위기를 맞이하면서 의류시장의 외형적 규모와 소비자들의 소비심리가 크게 위축되자, 국내 미시존 여성복 브랜드에서는 단품의 강화와 트랜드를 반영한 캐릭터성 보완의 두 가지 측면으로 시장구도를 형성하며 의류시장의 위기를 모면하려 노력한다. 그러나 IMF 이후, 베이직 상품의 판매비중이 늘어나게 되자 정장에 트랜드를 반영하기보다는 단품에 트랜드를 반영하려는 현상이 나타나게 되고, 대다수의 브랜드들이 기획비중을 줄이고 보완반응의 비중을 늘리면서 인기 브랜드의 인기 아이템에 대한 디자인 카피가 늘어나게 되면서, 브랜드의 차별화가 없어지는 공동화 현상이 심각하게 대두되게 되었다. (중략)

• Korean Architects
• /
• no.6 s.326
• /
• pp.116-119
• /
• 1996

대한주택공사에서는 대전 성남지구재개발 아파트 건설을 위한 기본설계 현상공모를 실시, 강남건축(조병기+곽동수+최병찬+정세진)안을 최우수작으로 선정, 지난 4월 29일 발표했다. 이번 최우수작은 주거의 질적 향상을 도모함은 물론 주변지역과 조화를 이룰 수 있도록 주거동과 층수에 변화형을 도입했고 개방감 있는 공간계획과 인공데크를 이용한 토지의 효율적인 활용과 공동체 실현을 위한 장소 제공 등에 역점을 둔 것으로 평가됐다. 우수작은 대전에 있는 목성건축(이택준)안이, 가작은 김상경 건축(김상경)안이 각각 선정됐다.

• 한국HCI학회:학술대회논문집
• /
• 2009.02a
• /
• pp.1337-1341
• /
• 2009

한국 사회에서 동영상 컨텐츠와 UCC는 새로운 문화 현상으로 그리고 새로운 광고 도구로써 많은 기대를 받고 있다. 이에 본 연구에서는 한국의 대표 동영상 컨텐츠 사이트인 아프리카 사용자들을 대상으로 하여, 사용 활동을 기준으로 사용자 유형을 구분하고, 각 유형별 주요 이용 특성을 탐색하고자 하였다. 동영상 이용 활동 및 동영상 컨텐츠 커뮤니티 활동에 있어서의 사회적 자본 특성 문항, 총 96문항을 도구로 하여, 총 39명의 동영상 컨텐츠 이용자 활동을 분석하였다. 분석결과 동영상 컨텐츠 이용자 행동은 '깍쟁이', '시청자', '휴머니스트'의 세가지 유형으로 구분되었다. 또한 이 세 유형은 사이버 공동체에서의 사회적 자본 특성으로 언급되는 유대감, 신뢰, 규범, 교환 및 호혜성, 혜택 등 다섯가지 사회적 자본 특성에서 서로 다른 특성을 보이는 것으로 확인되었다. 본 연구는 동영상 컨텐츠 사이트를 단순히 동영상 컨텐츠를 교환하거나 소비하는 공간이 아닌 새로운 사이버 공동체의 장으로 활용할 수 있는 단서를 제공했다는데 그 의의가 있다.

• The Bulletin of The Korean Astronomical Society
• /
• v.37 no.1
• /
• pp.69.2-69.2
• /
• 2012

한국천문연구원과 일본국립천문대는 2006년부터 한일공동으로 한일공동VLBI상관기(KJJVC)를 개발하였다. 한일상관센터(KJCC)에 각 구성시스템을 설치한 후 최근까지 시험운영을 수행하였으나 한일공동VLBI상관기의 핵심인 VLBI상관서브시스템(VCS)에서 프린지회전 모듈이 정상적으로 동작하지 않는 것을 발견하여, 일본국립천문대 및 제작사와 함께 이 문제를 해결하였다. 프린지 회전모듈의 문제점은 상관결과를 AIPS 등에서 분석하면, Fringe fitting후에 Cross-power spectrum의 진폭과 위상성분이 고주파 영역에서 감쇠하는 현상이다. 본 발표에서는 VCS 프린지 회전모듈의 문제점 해결과 KJJVC를 구성하는 각 구성시스템의 현황, 그리고 운영에 대해 간략히 기술한다.

• Annual Conference of KIPS
• /
• 2002.11a
• /
• pp.61-64
• /
• 2002

본 논문에서는 다자간 멀티미디어 공동작업에서 QoS를 보장하는 영상, 음성 및 화이트보드 데이터의 효율적인 전송을 위해 IP 그룹화를 이용한 영상 및 데이터의 전송 시스템을 설계하고, 구현한다. 기존의 다자간 멀티미디어 공동작업에서 TCP 방식의 화이트보드 비트맵 데이터 전송으로 인해 발생하는 네트워크 병목현상을 해소하고 음성의 QoS를 보장하기 위해, IP 그룹화를 이용한 효율적인 영상 및 화이트보드 데이터의 전송을 제안, 구현함으로써 전송의 속도 향상 및 손실을 최소화한다.