• Title/Summary/Keyword: 부분 변형

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Evaluation of Shear Strength of Unreinforced Masonry Walls Retrofitted by Fiber Reinforced Polymer Sheet (FRP로 보강한 비보강 조적 벽체의 전단강도 산정)

  • Bae, Baek-Il;Yun, Hyo-Jin;Choi, Chang-Sik;Choi, Hyun-Ki
    • Journal of the Korea Concrete Institute
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    • v.24 no.3
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    • pp.305-313
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    • 2012
  • Unreinforced masonry buildings represent a significant portion of the existing and historical buildings around the world. Recent earthquakes have shown the need for seismic retrofitting for these types of buildings. Various types of retrofitting materials (i.e., shotcrete, ECC and Fiber Reinforced Polymer sheets (FRPs)) for unreinforced masonry buildings (URM) have been developed. Engineers prefer to use FRPs, because these materials enhance the shear strength of the wall without expansion of wall sectional area and adding weight to the total structure. However, the complexity of the mechanical behavior of the masonry wall and the lack of experimental data from walls retrofitted by FRPs may cause problems for engineers to determine an appropriate retrofitting level. This paper investigate in-plane behavior of URM and retrofitted masonry walls using two different types of FRP materials to determine and provide information for the retrofitting effect of FRPs on masonry shear walls. Specimens were designed to idealize the wall of a low-rise apartment which was built in 1970s in Korea with no seismic reinforcements with an aspect ratio of 1. Retrofitting materials were carbon FRP and Hybrid sheets which have different elastic modulus and ultimate strain capacities. Consequently, this study evaluated the structural capacity of masonry shear walls and the retrofitting effect of an FRP sheet for in-plane behavior. Also, the results were compared to the results obtained from the evaluation method for a reinforced concrete beam retrofitted with FRPs.

A Tag Flow-Driven Deployment Simulator for Developing RFID Applications (RFID 애플리케이션 개발을 위한 태그 흐름기반 배치 시뮬레이터)

  • Moon, Mi-Kyeong
    • The KIPS Transactions:PartD
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    • v.17D no.2
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    • pp.157-166
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    • 2010
  • More recently, RFID (Radio Frequency Identification) systems have begun to find greater use in various industrial fields. The use of RFID system in these application domains has been promoted by efforts to develop the RFID tags which are low in cost, small in size, and high in performance. The RFID applications enable the real-time capture and update of RFID tag information, while simultaneously allowing business process change through real-time alerting and alarms. These be developed to monitor person or objects with RFID tags in a place and to provide visibility and traceability of the seamless flows of RFID tags. In this time, the RFID readers should be placed in diverse locations, the RFID flows between these readers can be tested based on various scenarios. However, due to the high cost of RFID readers, it may be difficult to prepare the similar environment equipped with RFID read/write devices. In this paper, we propose a simulator to allow RFID application testing without installing physical devices. It can model the RFID deployment environment, place various RFID readers and sensors on this model, and move the RFID tags through the business processes. This simulator can improve the software development productivity by accurately testing RFID middleware and applications. In addition, when data security cannot be ensured by any fault, it can decide where the problem is occurred between RFID hardware and middleware.

Use of Super Elements for Efficient Analysis of Flat Plate Structures (플랫플레이트 구조물의 효율적인 해석을 위한 수퍼요소의 활용)

  • 김현수;이승재;이동근
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.16 no.4
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    • pp.439-450
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    • 2003
  • Flat plate system has been adopted in many buildings constructed recently because of the advantage of reduced floor heights to meet the economical and architectural demands. Structural engineers commonly use the effective beam width model(EBWM) in practical engineering for the analysis of flat plate structures. However, in many cases, when it is difficult to use the EBWM, it is necessary to use a refined finite element model for an accurate analysis. But it would take significant amount of computational time and memory if the entire building structure was subdivided with finer meshes. An efficient analytical method is proposed in this study to obtain accurate results in significantly reduced computational time. The proposed method employs super elements developed using the matrix condensation technique and fictitious beams are used in the development of super elements to enforce the compatibility at the interfaces of super elements. The stiffness degradation of flat plate system considered in the EBWM was taken into account by reducing the elastic modulus of floor slabs in this study. Static and dynamic analyses of example structures were performed and the efficiency and accuracy of the proposed method were verified by comparing the results with those of the refined finite element model and the EBWM.

Development of Stochastic Seismic Performance Evaluation Method for Structural Performance Point Based on Capacity Spectrum Method (역량스펙트럼법을 통한 구조물 성능점의 확률적 기반 내진성능평가기법 개발)

  • Choi, Insub;Jang, Jisang;Kim, JunHee
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.30 no.6
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    • pp.523-530
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    • 2017
  • In this study, a method of probabilistic evaluation of the performance point of the structure obtained by capacity spectrum method (CSM) is presented. The performance point of the 4-story and 1-bay steel structure was determined by using CSM according to ATC-40. In order to analyze whether the demand spectrums exceed the performance limit of the structure, the limit displacements are derived for the performance limit of the structure defined from the plastic deformation angle of the structural member. In addition, by selecting a total of 30 artificial seismic wave having the response spectrum similar to the design response spectrum, the fragility curves were derived by examining whether the response spectrum obtained from the artificial seismic wave were exceeded each performance limit according to the spectral acceleration. The maximum likelihood method was used to derive the fragility curve using observed excess probabilities. It has been confirmed that there exists a probability that the response acceleration value of the design response spectrum corresponding to each performance limit exceeds the performance limit. This method has a merit that the stochastic evaluation can be performed considering the uncertainty of the seismic waves with respect to the performance point of the structure, and the analysis time can be shortened because the incremental dynamic analysis (IDA) is not necessary.

Utilization and Excavation Practices of Fire-Fighting Vulnerable Zone Model (소방취약지 모델의 활용 및 적용사례 발굴)

  • Choi, Gap Yong;Chang, Eun Mi;Kim, Seong Gon;Cho, Kwang-Hyun
    • Spatial Information Research
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    • v.22 no.3
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    • pp.79-87
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    • 2014
  • In order to foster rapid disaster response and public life protection, National Emergency Management Agency has been trying to spread 'Emergency Rescue Standard System' on a national scale since 2006. The agency has also intensified management of firefighter's safety on disaster site by implementing danger predication training, specialized training and education and safety procedure check as a part of safety management officer duties. Nevertheless, there are limitations for effective fire fighting steps, such as damage spreading and life damage due to unawareness of illegal converted structure, structure transformation by high temperature and nearby hazardous material storage as well as extemporary situation handling endangered firefighter's life. In order to eliminate these limitations there is a need for an effort and technology application to minimize human errors such as inaccurate situational awareness, wrong decision built on experience and judgment of field commander and firefighters. The purpose of this study is to propose a new disaster response model which is applied with geospatial information. we executed spatial contextual awareness map analysis using fire-fighting vulnerable zone model to propose the new disaster response model and also examined a case study for Dalseo-gu in Daegu Metropolitan City. Finally, we also suggested operational concept of new proposed model on a national scale.

Effect of Leadership Style on the Satisfaction of Organizational Members : Focusing on the Transfomational Leadership (리더십 유형이 조직구성원의 만족도에 미치는 영향에 관한 연구 - 변혁적 리더십을 중심으로 -)

  • 이광재
    • KSCI Review
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    • v.1 no.2
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    • pp.47-72
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    • 1995
  • 지금까지 나타난 많은 리더십 이론이 주로 기독교 문화권인 서구에서 연구된 것을 문화권이 다른 우리나라에 적용하고자 하는 것이 기존의 연구 경향이었다. 오랫동안 전통이 되어 온 우리 특유의 조직 문화 중에서 특히 관료적이고 권위주의적인 조직 문화에 새로운 변화가 일어나고 있는 과도기적인 현시점에서 최근에 나타난 리더십 이론인 B.M.Bass의 변형적 리더십 이론을 모델로 하여 우리 기업에 적절한 리더십 유형을 찾는 것이 일차적 목적이며 여기서 찾아낸 리더십 유형 별로 조직원의 상사 만족도에 미치는 영향을 알아보는 것이 이 연구의 목적이었다. 따라서 이 논문에서 제시한 리더십 유형을 보면 변혁적 리더십 유형에 속하는 것으로 지원적 배려, 카리스마, 과업 동기 자극으로 3분류하였으며 거래적 리더십 유형에 속하는 것으로 상황적 보상, 예외 관리, 소극적 관리로 3분류하여 모두 6유형을제시하고 신뢰성과 타당성을 확인하였다. 실증 연구 결과를 보면 우리나라는 거래적 리더십유형인 상황적보상, 예외 관리, 소극적 관리가 모두 조직원의 상사 만족도에 영향을 미치는것으로 나타나 Bass의 주장과는 다소 상이하다. 그러나 변혁적 리더십 유형인 카리스마, 지원적 배려, 과업 동기 자극에서는 카리스마만이 조직원의 상사 만족도에 영향을 미치고 지원적 배려는 영향력의 정도가 미약하며 과업 동기 자극은 거의 영향을 미치지 못하는 것으로 나타났다. 따라서 리더의 부하 통솔 및 지도 방향에서 아직도 우리나라에서는 거래적 요소가 짙다는 것을 알 수 있었다. 비록 당분간은 리더가 거래적 리더십을 많이 사용하겠지만 기업의 역사가 길어지고 종업원의 교육 훈련의 기회가 많아지면 변혁적 리더십으로 전환되리라 생각된다.가 단층원주상피세포와 단층입방상피가 부위에 따라 다르게 분포하고 있으며, 상피세포 및 결합조직에는 두터운 근육층이 있어 음경의강한 운동성이 감지 되었다. 제주도 내의 서귀포 부근에서는 현재 천연기념물로 지정되어 있는 서귀포층내에서 많은 화석들이 산출되고 있다. 이 시대는 빙하기와 간빙기가 교호하던 시대로서, 분석 결과에 의하면 서귀포층이 쌓일 당시에 우리 나라는 빙하기의 영향을 받았던 것으로 생각된다.is)은 근섬유가 산재된 두꺼운 벽을 가졌으며 상음경보다 굵은 원통형이었다. 내강은 많은 돌출부에 의해 복잡하게 나뉘어 있으며 상피세포는 원주 세포로 이루어져 있었고 섬모는 관찰되지 않았다. 내강 내의 분비물과 세포의 형태로 보아 내강상피세포는 분비기능을 가진 것으로 사료된다.술적 문제가 적절히 해결되는 경우 비활성 가스 제너레이터는 민수용으로는 대형 빌딩, 산림, 유조선 등의 화재에 매우 적절히 사용되어 질 수 있을 뿐 아니라 군사적으로도 군사작전 중 및 공군 기지의 화재 그리고 지하벙커에 설치되어 있는 고급 첨단 군사 장비 등의 화재 뿐 아니라 대간첩작전 등에 효과적으로 활용될 수 있을 것으로 판단된다.가 작으며, 본 연소관에 충전된 RDX/AP계 추진제의 경우 추진제의 습기투과에 의한 추진제 물성 변화는 미미한 것으로 나타났다.의 향상으로, 음성개선에 효과적이라고 사료되었으며, 이 방법이 편측 성대마비 환자의 효과적인 음성개선의 치료방법의 하나로 응용될 수 있으리라 생각된다..7%), 혈액투석, 식도부분절제술 및 위루술·위회장문합술을 시행한 경우가 각 1례(2.9%)씩이었다. 13) 심각한 합병증은 9례(26.5%)에서 보였는데 그중 식도협착증이 6례(17.6%), 급성신부전증 1례(2.

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Social Perception on Biotechnology in Korea (생명공학에 대한 사회적 인식)

  • Cho Sung-Kyum;Yoon Jeong-Ro
    • Journal of Science and Technology Studies
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    • v.1 no.2 s.2
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    • pp.343-369
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    • 2001
  • Understanding of the social perception of biotechnology would facilitate the public awareness and debate over the social implications of biotechnology, leading to strengthened basis for social consensus. As a part of the ELSI (Ehical, Legal and Social Implications) project in Korea, the authors have launched a series of social surveys on the social perception of biotechnology. This article is based on the analysis of the first survey, conducted in October 2001. The data were collected through telephone survey on 500 adult respondents nationwide selected by a stratified sampling method. The survey addresses the following questions: What is the present state of public awareness and attitude toward a variety of medical and social applications of biotechnology, such as genetic testing, prenatal genetic screening and testing, xenotransplant, genetic screening for employment, central collection and management of genetic information, and GM food? What factors are related with this perception? The analysis shows that a majority of respondents are in favor of the medical applications. Concerning the social applications and GM food, however, the respondents express a high level of negative attitude a with significant portion of 'do not know' responses. The public perception of the biotechnology is not crystallized in coherent manner yet. The public perception is strongly influenced by mass media, which tend to deliver rather positive information on biotechnology. The analysis suggests that the production and dissemination of diverse information should be activated to reach a sound decision on controversial issues surrounding the development of biotechnology both at individual and societal level as well.

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Corrosion of Calcareous Rocks and Ground Subsidence in the Muan Area, Jeonnam, Korea (전남 무안지역에 분포하는 석회질암의 용식작용과 지반침하)

  • Ahn, Kun-Sang
    • The Journal of the Petrological Society of Korea
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    • v.16 no.2 s.48
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    • pp.47-58
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    • 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.

Analysis of ESD-Related Content in Clothing Management Unit of Technology and Home Economics Textbooks of 2015 Revised Curriculum (2015 개정 교육과정 중학교 기술·가정 교과서 '의복관리와 재활용' 관련 내용의 지속가능발전교육(ESD) 연관성 및 탐구적 성향 분석)

  • Jang, Dawon;Lee, Yoon-Jung;Lee, Sun Young
    • Journal of Korean Home Economics Education Association
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    • v.32 no.1
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    • pp.89-105
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    • 2020
  • This study aimed at analyzing the clothing management units of technology and home economics textbooks in terms of their contents related to Education for Sustainable Development(ESD). The inquisitive tendency of the textbooks was also examined adopting the modified Romey's method, because it is known as an important factor in increasing student's class participation in sustainable clothing management and inducing practical behavior. First, the learning contents of clothing management unit were analyzed according to the social/political/cultural, environmental, and economic perspectives of ESD. As a result, ESD contents from social/political/cultural perspectives (safety, and health and food), environmental perspectives (natural resources, energy, and environmental problem), and the economic perspectives (sustainable production and consumption) were identified, with a heavy focus on environmental perspective. Secondly, Romey's inquisitive content analysis method was modified to analyze texts, pictures/charts, and learning activities of the clothing management unit. In all textbooks, facts and definitions were the dominant types of contents, which means less opportunities for development of inquiry ability. In conclusion, the ESD contents of the clothing management unit are inclined to the environmental perspective, and it is necessary that textbook development would need to be balanced between three perspectives. Also, future textbook authors will need to improve the inquisitive tendency of the textbooks to encourage student participation in class and induce practical application in real life.

A Methodology for 3-D Optimally-Interpolated Satellite Sea Surface Temperature Field and Limitation (인공위성 해수면온도 3-D 최적 내삽 합성장 생산 방법과 한계점)

  • Park, Kyung-Ae;Kim, Young-Ho
    • Journal of the Korean earth science society
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    • v.30 no.2
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    • pp.223-233
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    • 2009
  • Three-dimensional (3-D) optimally-interpolated sea surface temperature (SST) field was produced by using AQUA/AMSR-E satellite data, and its limitations were described by comparing the temporal average of sea surface temperatures. The 3-D OI (Optimum Interpolation) SST showed a small error of less than $0.05^{\circ}C$ in the central North Pacific, but yielded large errors of greater than $0.4^{\circ}C$ at the coastal area where the satellite microwave data were not available. OI SST composite around pixels with no observation due to heavy rainfall or cloudy pixels had estimation errors of $0.1-0.15^{\circ}C$. Comparison with temporal means showed a tendency that overall OI SSTs were underestimated around heavy cloudy pixels and smoothed out by reducing the magnitude of SST fronts. In the low-latitude areas near the equator, OI SST field produced discontinuity, originated from the window size for the OI procedure. This was mainly caused by differences in the spatial scale of oceanic features. Infernal Rossby deformation radius, as a measure of spatial stale, showed dominant latitudinal variations with O(1) difference in the North Pacific. This study suggests that OI SST methodology should consider latitudinally-varying size of window and the characteristics of spatial scales of oceanic phenomena with substantial dependency on latitude and vertical structure of density.