• 제목/요약/키워드: Post-Current

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해류도 그리기를 통한 중등학교 지구과학 교사들의 동해 해류에 대한 지식의 변화 분석 (An Analysis of the Change of Secondary Earth Science Teachers' Knowledge about the East Sea's Currents through Drawing Schematic Current Maps)

  • 박경애;박지은;이기영;최병주;이상호;김영택;이은일
    • 한국지구과학회지
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    • 제36권3호
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    • pp.258-279
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    • 2015
  • 이 연구의 목적은 해류 모식도 그리기를 통해 드러난 중등 지구과학 교사들의 동해 해류에 대한 지식의 변화를 분석하는 것이다. 이를 위해 32명의 중등 지구과학 교사들이 총 6시간의 해류도 관련 학습과 실습 과정을 거쳤으며, 사전과 사후 그리고 지연된 사후 동해 해류 모식도 그리기를 수행하였다. 또한, 작성된 해류 모식도를 수치화 과정을 거쳐 변환하여 이 해류 모식도에서 드러난 참여 교사들의 동해 해류에 대한 지식의 변화를 분석하였다. 동해 해류에 대한 참여 교사들의 사전 지식을 분석한 결과, 해류도에 대한 기초적인 지식은 가지고 있는 것으로 나타났으나, 몇몇 개념에 대해서는 잘못된 지식을 가진 것으로 분석되었다. 3차에 걸쳐 작성된 참여 교사들의 동해 해류 모식도를 분석한 결과, 연수 후 동해 해류 양상에 대한 지식이 증가하는 것으로 나타났으며, 교사에 따른 차이는 감소하는 것으로 나타났다. 이러한 경향은 연수 직후보다는 지연된 사후 단계에서 더욱 뚜렷하게 나타났다. 해류도 실습활동에 대한 사후 설문을 분석한 결과, 참여 교사들은 해류도와 해류 교육의 필요성, 과학적 지식에 근거한 교과서 해류도의 개선을 강하게 인식하고 있었다. 또한, 실습활동에 대해 매우 높은 만족도를 나타내었으며, 내용 지식의 중요성 인식 및 교수 전략과의 연계, 중등 교육과정 개선의 필요, 과학 지식의 본성에 대한 인식 등 다양한 측면에서 실습활동의 의미를 부여하였다. 이러한 결과는 교사의 교과내용학 지식이 효과적인 과학 교수에 중대한 역할을 함을 시사한다.

한국에서의 환경영향평가와 환경측정 (Environmental Impact Assessment and Environmental Monitoring in Korea)

  • 강인구;김명진
    • 환경영향평가
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    • 제4권3호
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    • pp.31-39
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    • 1995
  • Environmental Impact Assessment (EIA) is composed of various procedures, such as screening, scoping, inventory survey, prediction, assessment, alternative assessment, mitigation measures, and post management. Environmental monitoring data for air quality or water quality, etc. is applied in the EIA process, especially in prediction and post management. As an effective tool of environmental monitoring, the remote sensing method, introduced recently, was used in collecting nationwide data concerning ecosystem and land use. This article explains the current monitoring status in Korea. Monitoring factors include air quality, water quality, soil, ocean, odor, noise, and ecosystems. This report explains the organization of the environmental monitoring system managed by the Ministry of Environment in Korea. Furthermore, it shows the environmental criteria and environmental policies applied to EIA in Korea.

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프라이자흐 모델링과 유한요소법을 이용한 라인 스타트 영구자석 전동기의 영구자석 자화 특성 분석 (PM Magnetization Characteristics Analysis of a Post-Assembly Line Start Permanent Magnet Motor using coupled Preisach Modeling and Finite Element Method)

  • 라영각;이중호
    • 전기학회논문지
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    • 제63권4호
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    • pp.469-475
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    • 2014
  • This paper deals with the characteristics evaluations of PM magnetization using stator coil in a Post-Assembly Line Start Permanent Magnet Motor (LSPMM) using a coupled Finite Element Method (FEM) and Preisach modeling, which is presented to analyze the magnetic characteristics of permanent magnets. The focus of this paper is the characteristics analysis relative to magnetizing direction and quantity of permanent magnets due to the eddy current occurring in the rotor bar during magnetization of Nd-Fe-B.

Post-Damage Repair of Prestressed Concrete Girders

  • Ramseyer, Chris;Kang, Thomas H.K.
    • International Journal of Concrete Structures and Materials
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    • 제6권3호
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    • pp.199-207
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    • 2012
  • Concrete is an economical construction material and for that reason it is widely used in buildings and infrastructures. The use of deicing salts, expansion joint failure, and freeze-thaw cycles have led to concrete bridge girders experiencing corrosion of steel reinforcement and becoming unsafe for driving. The goal of this research is to assess the effectiveness of current and possible repair techniques for the end region of damaged prestressed concrete girders. To do this, three American Association of State Highway and Transportation prestressed concrete girders were tested to failure, repaired, and retested. Three different repair materials were tested including carbon fiber, glass fiber, and surface mounted rods. Each different repair material was also tested with and without injected epoxy. Comparisons were then made to determine if injecting epoxy had a positive effect on stiffness and strength recovery as well as which repair type regained the largest percentage of original strength.

A Robust Method for Speech Replay Attack Detection

  • Lin, Lang;Wang, Rangding;Yan, Diqun;Dong, Li
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제14권1호
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    • pp.168-182
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    • 2020
  • Spoofing attacks, especially replay attacks, pose great security challenges to automatic speaker verification (ASV) systems. Current works on replay attacks detection primarily focused on either developing new features or improving classifier performance, ignoring the effects of feature variability, e.g., the channel variability. In this paper, we first establish a mathematical model for replay speech and introduce a method for eliminating the negative interference of the channel. Then a novel feature is proposed to detect the replay attacks. To further boost the detection performance, four post-processing methods using normalization techniques are investigated. We evaluate our proposed method on the ASVspoof 2017 dataset. The experimental results show that our approach outperforms the competing methods in terms of detection accuracy. More interestingly, we find that the proposed normalization strategy could also improve the performance of the existing algorithms.

이탈리아 트랜스아방가르드 작품에 나타난 장식적 요소연구 (21A Study of interior constituents that appear trans avant-garde works in italy)

  • 정종환
    • 한국실내디자인학회:학술대회논문집
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    • 한국실내디자인학회 2003년도 춘계학술발표대회 논문집
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    • pp.160-165
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    • 2003
  • Art of today is expressed in various images incorporated in industrial development and visible in industrial parks, modern cities. Avant garde art and modernism brought abstract and conceptual art into conflict in the early 20th century and they absorbed elements of each other and grew into post modernism, which emerged in the 1960s and is still current. The avant garde challenged what was lofty and sometimes opposed modernism and sometimes fed it in cycles until post modernism was established. 'Trans avant garde', which, unlike modernism asserted individual expression, also appeared in the 1970s. Trans avant garde is spiritual art in which the artist's conversation with his soul returns. This study examines the readjustments the trans avant garde is making in its relationship with the dominant ethos of different values and offers the world art with important spiritual beauty. Trans avant garde art takes many forms, from thing to huge, which are manifested every where in architecture, interior design and everyday life.

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소포 집배송 서비스를 위한 GIS, GPS 및 최적화 기술의 통합 (Integrating GIS, GPS, and Optimization Technologies for Pick-up/Delivery Service)

  • 정훈;임승길
    • 경영과학
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    • 제21권3호
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    • pp.115-127
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    • 2004
  • In this paper, we describe an intelligent monitoring and control system for pick-up/delivery service. This system applies geographical information system(GIS), global positioning system(GPS) and wireless communication technologies for managing pick-up/delivery operations more effectively. It consists of three subsystems, pick-up/delivery sequence planning system, pick-up/delivery monitoring system, and PDA execution system. Pick-up/delivery sequence planning system generates routes and schedules for pick-up/delivery using GIS and optimization techniques. Pick-up/delivery monitoring system monitors current positions of vehicles and actual pick-up/delivery results as compared with planned routes and visit times, while PDA execution system transmits information for vehicles positions and actual pick-up/delivery results using GPS and wireless communication technologies. The intelligent monitoring and control system is currently being used for the pick-up parcel service in a local post office of Korea Post.

주성분 분석(PCA)에 의한 항공기 왕복 엔진의 구조 건전도 모니터링 (Structural Health Monitoring of Aircraft Reciprocating Engine Based on Principal Component Analysis (PCA))

  • 김지환;박성은;이형철
    • 항공우주시스템공학회지
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    • 제6권1호
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    • pp.13-18
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    • 2012
  • This paper presents a structural health monitoring method of aircraft reciprocating engine using Principal Component Analysis (PCA) which analyzes vibration expressed by Averaged Normalized Power Spectral Density (ANPSD). Because ANPSD of the rotating shaft is sensitive to the rotating speed, this paper proposes to use a post-processing method of ANPSD is used to reduce the sensitivity. The PCA extracts compressed information from the post-processed ANPSDs and the information means the difference between current and normal cases of the engine. The experimental results demonstrate the feasibility and effectiveness of the proposed method to detect abnormal cases of the engine.

과학교육과정 및 과학 교수/학습의 이론적 배경과 미래의 과학교육에 대한 시사점 (Analysis of Theoretical Background for Current Research on Science Curriculum and Teaching/Learning and Implications for Future Science Education)

  • 조희형
    • 한국과학교육학회지
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    • 제8권2호
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    • pp.33-41
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    • 1988
  • During the last decade researchers in science education and psychology have emphasized the importance of children's ideas, or "what they already know", which they bring to their related learning situations. Most research reports on the children's prior ideas reject both the traditional epistemologies and the conventional learning theories. Therefore, this study has its objective to analyze the traditional epistemologies as well as post-positivism contemporarily in vogue, to examine both the conventional learning theories and the constructivism of psychology, and then, based on the analyses, to draw the implications for the future science education. The implications are described under such headings as the nature of science, the science curricula, and the science teaching/learning. The implications are drawn in logical relation to the post-positivism and constructivism, and some of which are empirically validated by the research on the children's conceptions.

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Effects of additives and post-treatments on emission characteristics of carbon nanotubes field emitters by screen printing method

  • Lee, Duck-Jin;Kim, Sam-Soo;Lee, Yang-Kyu;Chun, Hyun-Tae;Lee, Dong-Gu
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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    • pp.1447-1450
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    • 2005
  • Carbon nanotube field emission display devices were fabricated using screen printing techniques. The CNT pastes are composed of organic binder, CNT, and additive materials such as glass frit, silver or ITO powders. The change in mixing ratio of various organic binders in CNT paste varied the electron emission characteristics. With increasing the contents of additive materials in CNT paste, turn-on field were increased, leading to decrease in electron emission current. The post-treatment process in this study induced the vertical alignment of carbon nanotubes on glass, resulting in the improvement of electron emission uniformity.

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