• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.360-360
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• 2021

최근 지구 온난화와 기후변화, 그에 따른 이상기후로 인하여 대규모 홍수피해가 발생함과 동시에 오랜 시간 동안 가뭄이 지속되어 재난관리가 더욱 중요하게 인식되고 있다. 영산강홍수통제소는 효율적인 재난관리를 위해 영산강권역의 5대강 및 해안지역의 수위·강수량·유량 등 수문조사시설을 설치·운영하여 홍수·갈수예보를 통해 재난관리를 수행하고 있다. 2020년 영산강홍수통제소 관할권역의 홍수기 강수량은 예년에 비해 약 150% 내외의 많은 강수가 내렸다. 영산강, 섬진강, 동진강 수계는 8월에 가장 많은 비가 내려 487.4 mm, 619.5 mm, 503.7 mm의 강수가 기록되었고, 8월의 예년 대비 강수량은 181%, 200%, 192% 수준이었다. 만경강과 탐진강은 7월 강수량이 535.1 mm, 365.5 mm로 가장 많았고, 7월 강수량의 예년비는 193%, 141%의 수준이었다. 특히 8.7~8.8일 섬진강 유역의 남원시(신덕리)와 영산강 유역 담양군(광주댐)에는 각각 542 mm, 654 mm의 기록적인 강수가 관측되었다. 이틀간의 집중호우로 영산강 및 섬진강 유역의 여러 지역에서 홍수피해가 발생했으며, 특히 남원시, 구례군, 하동군에서 홍수 피해 규모가 컸다. 영산강홍수통제소는 2020년 총 51회의 비상근무를 실시하여 홍수상황에 대응 하였으며, 15개 홍수특보지점 중 탐진강 유역 장흥군(예양교)를 제외한 14개 지점에 대해 홍수주의보 22회, 홍수경보 14회 등 36회의 홍수특보를 발령하였다. 홍수특보 지점의 대부분 지점에서 기왕 최고치에 근접하거나 이를 초과하였다. 홍수주의보 수위를 초과한 지점은 총 14개소이며, 이 중 계획홍수위 초과 6개소, 홍수경보 수위 초과 5개소, 홍수주의보 수위 초과 3개소이다. 또한 위기단계별 홍수정보 943건을 30개기관 595명에게 제공하여 관계기관의 방재활동을 지원하였으며, 관할수계 다목적댐 3개소, 발전댐 1개소, 용수댐 1개소, 농업용저수지 10개소, 다기능보 2개소, 홍수조절지 2개소에 181회의 방류승인을 통해 홍수조절을 실시하였다. 본 연구에서는 2020년 홍수기간 동안 영산강 및 섬진강의 홍수상황 및 홍수대응 현황을 분석하고, 향후 홍수상황에 대비코자 한다.

• Journal of The Korean Association For Science Education
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• v.27 no.9
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• pp.832-847
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• 2007

The purpose of the study was to analyze and interpret parent-child dyadic discourses in depth with emphases on the ZPD system in a museum, an informal learning setting. Second graders and their parents from Seoul and its environs were voluntarily participated in the study. Data were collected from the museum documents, the photos of exhibits, and the video recordings of dyadic discourses at and between exhibits. The documents and the photos were analyzed to investigate what the topics, medium and goals of the exhibits were. The video recordings were all transcribed and analyzed to understand what and how they talked to each other through the lens of the ZPD system; situation definition, intersubjectivity, and semiotic mediation, The results of the study consisted of two parts. First, it showed that parent-child dyadic discourses were categorized in four: (1) within the actual developmental level; (2) in the zone of proximal development; (3) toward the potential developmental level; and (4) out of developmental level. The most common categories were the dyadic discourses within the actual developmental level and in the zone of proxima I development. Second, the representative cases in each categories were described and interpreted to understand the nature of parent-child dyadic discourses. It can be concluded that we gained some important understandings of an intrinsic attribute of parent-child discourses in a museum, an informal learning setting. Based on the results of the study, it can be suggested that museums make efforts to cultivate the affordance of exhibit environment to promote visitor's learning.

• Aerospace Engineering and Technology
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• v.13 no.1
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• pp.142-152
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• 2014

This paper analyzes the conjunction events of Korea satellites by year or kind of satellite using CSM, which is provided by JSpOC. If multiple CSM for single conjunction event are available, consistency analysis is performed using minimum range of CSM. And this paper presents the contact analysis results with space objects if there is a radar system in Korea. The effectiveness of Korea's radar system is analyzed by calculating the access time or frequency with space objects. Furthermore, we investigate the radar systems of other space agencies and find the specific parameter depending on the operating environment. Using this information, we define the requirements of radar system, which is appropriate the Korea.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.2
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• pp.320-326
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• 2009

Providing visual field for a driver is one of the most important things for safe driving. Therefore, it will be a first step fur the safe driving that the driver recognizes front and back outside scenes within short time in the car. Specially, it is essential to take the visual field in frequently foggy area where the traffic accident can cause highest rank in the number of deaths. In this paper, our technique can provide the visual field by displaying the location of neighboring vehicles on the monitoring system, embedded board navigator in the car, using the location information of the vehicles from GPS(Global Positioning System) in real time. It is expected that this system can contribute to help safe driving and to lower collision accidents by guiding to cope with unexpected circumstances.

• Proceedings of the KIEE Conference
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• 2007.10a
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• pp.209-210
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• 2007

본 연구에서는 건설현장에서 빈번히 발생하는 안전사고를 줄이기 위해 근로자의 안전모 턱끈 착용을 도와주고 안전관리 감독자가 쉽게 확인 및 관리할 수 있는 전자식 안전모 착용 확인 시스템을 개발하였다. 안전모 착용을 확인하기 위해 마그네틱 근접 센서를 안전모 턱끈에 장착하여 안전모 착용 여부를 검출할 수 있게 하였다. 그리고 무선 센서 네트워크를 구성하기 위해 424.700MHz 주파수를 사용하는 무선 모듈을 개발하여 안전모의형에 장착하여 센서 노드(Sensor Node)를 구성하였으며, 메쉬 토폴로지(Mesh Topology)를 적용하였다. 그리고 중앙 관리실에서 근로자의 상황 인지를 위한 안전모 확인 모니터링 시스템을 개발하였다. 본 시스템으로 인하여 근로자의 안전을 도모하고, 안전 사고에서 근로자의 부상 및 인명 손실을 최소화할 수 있으며, 건설용 엘리베이터 안전 상황 인지, 타워크레인 안전 문제등의 시스템으로 활용이 가능할 것이다.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.5
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• pp.883-888
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• 2022

In this paper, we developed a portable IoT device for lifesaving and a web service prototype based on the device and evaluated its functions. The portable IoT terminal for lifesaving is designed for easy to carry, and to communicate possibly between user by LTE Cat. M1 modem which is a low-power broadband IoT communication technology. So, in case of emergency, it is possible to give priority to nearby users and to determine the exact location with built-in GPS. In the future, it will be designed to enable rescue requests in various ways, such as button signals, voice, and acceleration changes.

• Journal of the Korean earth science society
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• v.30 no.1
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• pp.127-140
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• 2009

The purpose of this study was to explore the characteristics of children's interactive learning focusing on the Vygotsky's ZPD (the zone of proximal development) in a natural history museum as a representative free-choice learning context. We focused on the understanding of peer dyadic discourses and data were collected from 13 peer groups of children (3rd and 4th graders) who were videotaped all conversations occurred as they visited around the exhibits with no predetermined path. The transcribed data were analyzed by the developmental level of ZPD system and the discourse within an ADL (an actual developmental level) was overwhelmingly common in the conversations between child-child dyads. The representative discourse by discourse types were parsed according to three constructs of ZPD. Children formed the intersubjectivity through semiotic mediation such as conversations and exhibits and ended up with the similar situation definition. In conclusion, the details of discourses of the most impressive dyad were looked into focusing on the scientific concept. The study implies that a natural history museum becomes a meaningful resource to offer a deeper understanding of the nature of children's learning as an informal learning setting.

• Journal of Broadcast Engineering
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• v.26 no.3
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• pp.308-320
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• 2021

Conventional image quality studies have been focused on 'naturalness' and has relied on memory color. Memory colors are mainly formed for familiar objects with prior experience, and the more faithfully these memories are reflected, the more naturalness of the reproduced image quality increases. In particular, the brightness and saturation of memory colors play an important role in increasing the preference of image quality as well as naturalness. Therefore, in the case of existing image quality studies, image quality characteristics were studied focusing on natural objects and people with memory. We extracted representative images of each genre (sports, documentaries, news, entertainment and music, and movies), adjusted the brightness, contrast, and saturation of each image, and conducted an experiment to evaluate perceived quality. Based on situational context, the results of this classification indicated that genres of television content can be divided into two categories: proximate and indirect experiences. Proximate experience best characterizes outdoor sports, dramas, and nature documentaries, where their image qualities have shown to have a strong correlation with brightness and contrast. On the other hand, indirect experience best characterizes news, music shows and SF/action movies. The image quality perception for indirect experiences was shown to be closely related to and optimized by contrast and saturation.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.6
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• pp.46-52
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• 2016

Quasi-Orthogonal STBC (QO-STBC) scheme is proposed conventionally achieving approximate full rate and full diversity in more than 3 transmit antenna and open-loop environmen.. But, conventional QO-STBC has disadvantage that performance degradation by interference terms of detection matrix and high decoding complexity. Recently, this interference cancellation scheme of low decoding complexity by multiplying specific rotation matrix is proposed. We propose more general interference cancellation scheme by using EVD(Eigenvalue Decompostion).

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.133_134
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• 2009

과거 국내 전력계통은 선진국에 비하여 주파수 품질이 현격하게 저하되어 계통운영자는 적정범위 이내로 주파수를 유지하는 것이 중요한 책무였다. 그러나, 계통수요와 계통연계의 지속적인 증가로 인하여 현행 주파수 유지율은 99.9% 수준에 근접하고 있다. 이러한 상황에서는 막대한 비용을 투자하여도 주파수 품질을 개선하기는 쉽지않다[1]. 주파수 유지율이 포화상태에 이른 주요 선진국들은 오래전부터 표준편차를 이용하여 주파수를 평가해오고 있다[2]. 따라서, 국내계통의 주파수 평가방법도 새로운 변화가 필요한 시점이다.