• Phonetics and Speech Sciences
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• v.14 no.3
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• pp.51-66
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• 2022

This study aims to help Korean English learners to learn English pronunciation by revealing which suprasegmentals affect the implementation of English sentences closer to native English speakers when they read English sentences. To this end, Korean middle school English learners were selected as subjects and research data were gathered through sentence types (declarative, interrogative, imperative, and exclamative), as well as syllables. Speech rate, pause frequency, pause duration, F0 range, and rhythm among suprasegmentals were used for analysis of these English sentence utterances. Mean analysis, correlation analysis, and regression analysis were performed. The results showed that speech rate, pause frequency, pause duration, and F0 range affected the evaluation of fluency levels. In the regression analysis between all suprasegmentals and fluency levels, the suprasegmentals that most affected fluency levels were speech rate and F0 range. Rhythm had no meaningful relation with fluency levels. Therefore, when teaching English pronunciation, it is necessary to teach students to increase their speech rate and F0 range. In addition, students should be trained to reduce both the number and the duration of pauses during utterance to improve their fluency. It is noteworthy that of the four sentence types, exclamative sentences were produced with faster speech rate, fewer pauses, shorter pause duration, and higher rhythm values.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.7
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• pp.1120-1128
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• 2022

In the event of a marine accident, the longer the exposure time to the sea increases, the faster the chance of survival decreases. However, because the search area of the sea is extremely wide compared to that of land, marine object detection technology based on the sensor mounted on a satellite or an aircraft must be applied rather than ship for an efficient search. The purpose of this study was to rapidly detect an object in the ocean using a hyperspectral image sensor mounted on an aircraft. The image captured by this sensor has a spatial resolution of 8,241 × 1,024, and is a large-capacity data comprising 127 spectra and a resolution of 0.7 m per pixel. In this study, a marine object detection model was developed that combines a seawater identification algorithm using DBSCAN and a density-based land removal algorithm to rapidly analyze large data. When the developed detection model was applied to the hyperspectral image, the performance of analyzing a sea area of about 5 km² within 100 s was confirmed. In addition, to evaluate the detection accuracy of the developed model, hyperspectral images of the Mokpo, Gunsan, and Yeosu regions were taken using an aircraft. As a result, ships in the experimental image could be detected with an accuracy of 90 %. The technology developed in this study is expected to be utilized as important information to support the search and rescue activities of small ships and human life.

• Journal of Korea Water Resources Association
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• v.55 no.4
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• pp.301-308
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• 2022

Algae is an indispensable primary producer in the ecosystem by supplying energy to consumers in the aquatic ecosystem, and is largely divided into green algae, blue-green algae, and diatoms. In the case of blue-green algae, the water temperature rises, which occurs in the summer and overgrows, which is the main cause of the algae bloom. Recently, the change in the occurrence time and frequency of the algae bloom is increasing due to climate change. Existing algae survey methods are performed by collecting water and measuring through sensors, and time, cost and manpower are limited. In order to overcome the limitations of these existing monitoring methods, research has been conducted to perform remote monitoring using spectroscopic devices such as multispectral and hyperspectral using satellite image, UAV, etc. In this study, we tried to confirm the possibility of species classification of remote monitoring through laboratory-scale experiments through algal culture and river water collection. In order to acquire hyperspectral images, a hyperspectral sensor capable of analyzing at 400-1000 nm was used. In order to extract the spectral characteristics of the collected river water for classification of algae species, filtration was performed using a GF/C filter to prepare a sample and images were collected. Radiation correction and base removal of the collected images were performed, and spectral information for each sample was extracted and analyzed through the process of extracting spectral information of algae to identify and compare and analyze the spectral characteristics of algae, and remote sensing based on hyperspectral images in rivers and lakes. We tried to review the applicability of monitoring.

• Polymer Science and Technology
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• v.15 no.3
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• pp.296-302
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• 2004

최근 분자들의 자기조립 현상을 나노-바이오 소자 개발에 응용하는 연구가 활발히 진행되고 있으며, 이러한 응용을 위한 대표적인 자기조립체로는 양친성 계면활성제, 블록공증합체, 콜로이드와 초분자체를 들 수 있다. 대부분의 콜로이드가 구형 모양으로 vander Waals interaction에 의하여 3-D결정 (crystal) 형태의 자기조립구조를 형성하는 반면에, 콜로이드를 제외한 대부분의 자기조립체는 적정 조건에서 액정 (liquid crystals), 결정 (crystal) 및 무정형 (amorphous)을 형성한다. 적용하고자 하는 응용의 범위와 재료의 특성에 따라서 각 상태 (phase)를 이용할 수 있으나, 액정상을 이용하는 것과 결정상을 이용하는 경우가 대부분이다. (중략)

• Proceedings of the KSRS Conference
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• 2006.03a
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• pp.283-286
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• 2006

인공위성 영상자료를 이용하는 원격탐사는 지질, 환경, 지형도제작 등 다양한 분야에서 연구되고 있다. 특히 다중 및 초분광영상자료는 태양을 에너지원으로 하여 지표면 전자기파의 반응을 영상화하는 다중 및 초분광영상자료의 활용을 위해 분광반사율정보가 더욱 활발하게 이용될 것으로 기대된다. 본 연구에서는 고창지역에 대해 주기적으로 실시하고 있는 분광반사율 및 USGS 분광라이브러리 성과를 이용하여 다중파장대 위성영상자료인 ASTER와 분광반사율을 이용한 위성영상의 활용가능성 및 검보정의 가능성을 제시 하고자 한다.

• Proceedings of the Optical Society of Korea Conference
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• 2003.02a
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• pp.24-25
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• 2003

새로이 합성된 비선형 광학 물질인 옥타폴 분자들의 1차 초분극율ß을 Hyper-Rayleigh scattering(HRS) 방법을 이용하여 측정하였다. 시료의 흡수와 형광효과를 피하기 위해, 광원으로 1560nm를 사용하였다. YAG(1064nm) 레이저로 펌핑한 Raman-Cell(D$_2$ gas) 장치를 제작하여, 높고 안정한 파워의 1560nm를 발생하여 실험에 사용하였다. 또한 1064nm를 이용하여 측정한 결과와 비교하였다. (중략)

• Proceedings of the Korea Contents Association Conference
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• 2016.05a
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• pp.325-326
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• 2016

해역과 육역을 포함하는 연안지역을 대상으로 하여 CASI-1500에 의해 취득된 항공 초분광 영상을 이용하여 토지피복분류를 행하고 이 분류결과로부터 육역과 해역의 경계를 추출하였다. 또한 현재 활용되고 있는 방법에 의하여 LiDAR 데이터로부터 해안선을 검출하였다.

• Proceedings of the Korean Institute of Landscape Architecture Conference
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• 2022.10a
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• pp.122-123
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• 2022

• Information and Communications Magazine
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• v.13 no.10
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• pp.76-85
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• 1996

• Optical Science and Technology
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• v.16 no.4
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• pp.36-40
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• 2012