• Korean Journal of Remote Sensing
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• v.39 no.5_4
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• pp.1135-1144
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• 2023

Many agricultural reservoirs in South Korea, constructed before 1970, have become aging facilities. The majority of small-scale reservoirs lack measurement systems to ascertain basic specifications and water levels, classifying them as unmeasured reservoirs. Furthermore, continuous sedimentation within the reservoirs and industrial development-induced water quality deterioration lead to reduced water supply capacity and changes in reservoir morphology. This study utilized Light Detection And Ranging (LiDAR) sensors, which provide elevation information and allow for the characterization of surface features, to construct high-resolution Digital Surface Model (DSM) and Digital Elevation Model (DEM) data of reservoir facilities. Additionally, bathymetric measurements based on multibeam echosounders were conducted to propose an updated approach for determining reservoir capacity. Drone-based LiDAR was employed to generate DSM and DEM data with a spatial resolution of 50 cm, enabling the display of elevations of hydraulic structures, such as embankments, spillways, and intake channels. Furthermore, using drone-based hyperspectral imagery, Normalized Difference Vegetation Index (NDVI) and Normalized Difference Water Index (NDWI) were calculated to detect water bodies and verify differences from existing reservoir boundaries. The constructed high-resolution DEM data were integrated with bathymetric measurements to create underwater contour maps, which were used to generate a Triangulated Irregular Network (TIN). The TIN was utilized to calculate the inundation area and volume of the reservoir, yielding results highly consistent with basic specifications. Considering areas that were not surveyed due to underwater vegetation, it is anticipated that this data will be valuable for future updates of reservoir capacity information.

• Archives of design research
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• v.17 no.2
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• pp.113-122
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• 2004

Modern society came to enjoy dramatically advanced information technologies by the digitalization of New Media with the improvement of communication technologies and interaction between various information system and technologies. New service by web, not only text but image, audio and moving image have opened new experience possible for us. The development was possible because the web has characteristics of media making Remediation of various media possible. The web has remediated newspaper, magazines, TV, audio, movie by taking them, competing with them, attacking them and absorbing them. As a result, now we can enjoy various characteristics of different media at the Web. This study is to look into the effectiveness of Remediation at web design through various case studies. This study also is to seek more effective methods of expressions in the web and future improvement direction.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.99-104
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• 2009

최근 멀티미디어 기술과 가상/증강현실 기술의 발전으로 사용자에게 몰입감 있는 콘텐츠를 제공하는 여러 시스템들이 제안되고 있다. 또한 기존의 시각과 음향효과만으로 이루어진 시스템의 한계를 넘어서 실제와 같은 느낌을 전달할 수 있는 햅틱기술을 적용하여 보다 몰입감있는 체험형 실감책들이 고안되고 있다. 본 논문은 과학교과서를 중심으로 과학적 이론을 보다 효과적으로 가르치고 배우기 위해 필요한 다양한 촉감(Haptic)을 분류하고, 이를 실감책에 적용하여 책이 담고 있는 주요 내용 또는 삽화와 관련된 다양한 멀티미디어 콘텐츠를 가상/증강환경에서 시청각정보와 함께 촉각콘텐츠를 독자에게 제공함으로써 보고, 듣고 만질 수 있는 적극적인 촉감 상호작용이 가능한 실감책 ('Sil-Gam' Book) 시스템의 기본 프레임워크를 제시한다. 제시된 실감책은 크게 세 부분으로 구성된다. 첫째, 실감책을 읽고 있는 사용자의 손가락의 위치, 시선과 같은 사용자의 움직임을 추적하고 책의 크기, 페이지 등을 인식하는 센서가 부착된 센싱 부; 둘째, 장비에 따라 적용 가능한 촉감 속성, 물체의 움직임에 따라 적용할 수 있는 촉감 속성등 다양한 촉감콘텐츠의 속성을 저작하고 편집하는 소프트웨어 부; 마지막으로 사용자에게 저작된 실감 콘텐츠를 사용자가 쉽고 직관적으로 체험하게 하기 위한 디스플레이부로 구성된다. 여기서 디스플레이 부는 세부적으로 시청각 콘텐츠를 전달하는 시청각 디스플레이 부와 역촉감 콘텐츠를 전달하는 역촉감 디스플레이부로 구성된다. 본 논문에서는 또한 실감책 촉감 저작도구를 사용하여 제시할 수 있는 다양한 촉감을 중고등학교 교육과정에서 배우는 과학 이론에 적용하여 과학 실험시 경험할 수 있는 다양한 역/촉감을 전달하는 몇 가지 시나리오를 예시하였다.

• Journal of Advanced Navigation Technology
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• v.20 no.4
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• pp.298-304
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• 2016

In this paper, a wavelet packet transform method is proposed for improving the altitude control performance of quadrotor UAV using an ultrasonic rangefinder. A ground tests are conducted using an ultrasonic rangefinder that is much used for vertical takeoff and landing. An ultrasonic rangefinder suffers from signal's spike due to specular reflectance and acoustic noise. The occurred spikes in short time span need to be analyzed at both sides time and frequency domain. The analyzed spikes of the ultrasonic rangefinder using a wavelet packet transform. Compared with the discrete wavelet transform, the wavelet packet decomposition can obtain more abundant time-frequency localization information, so it is more suitable for analyzing and processing ultrasonic signals spike. Experimental results show that it can effectively remove the spikes of the ultrasonic rangefinder.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.4
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• pp.282-288
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• 2014

Three-dimensional multimedia industry such as 3D TV, movie and broadcast has been developed vividly. For generating 3D contents with high quality, virtual auditory display, so called VAD, is being researched to offer more realistic experience to listeners. When people render VAD using headphones or two speakers, head-related transfer function(HRTF) plays a key role. The best solution is measuring all individuals' HRTFs, but it is hard to measure all listeners' HRTFs. To overcome this difficulty, many research groups have tried to construct their own measurement system and to build HRTF databases. However, some of them have not enough subjects or spatial resolution and they are mainly focused on Caucasian. There exists difference between Korean and Caucasian in a view of physical features. In other words, if Koreans hear three-dimensional sound rendered by HRTF database based on Caucasian, performance might be hindered. To verify this possibility and remedy the drawbacks, construction of new HRTF database aimed at Korean is needed. Therefore, our laboratory built HRTF measurement system which can measure HRTF of three-dimensional space with dense spatial resolution. With this system, 55 Korean males and 45 females' HRTFs were measured and Korean HRTF database was built based on these data.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.23 no.1
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• pp.39-47
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• 2005

In this study, three-dimensional information of submarine topography acquired by assembling DGPS method and echo sounder which mainly used in the marine survey. Moreover, the hopper dredging capacity in harbor public affair has been calculated by utilizing kriging, radial basis function and nearest neighbor interpolation. Also, utilization of DGPS/Echo sounder method in calculation of the dredging capacity have been confirmed by comparing and analyzing the hopper dredging capacity and the actual one as per each interpolation. According to this comparison result, in case of applying kriging interpolation, some 1.89% of error rate has been shown as difference of the contents is 15,364 ㎥ and in case of applying radial basis function interpolation and nearest neighbor interpolation, 3.9% and 4.4% of error rates have respectively shown. In case the study for application of the proper interpolation as per characteristics of submarine topography, is preceded in calculation of the dredging capacity relevant to harbor public affairs, it is expected that more speedy and correct calculation for the dredging capacity can be made.

• Journal of Korea Multimedia Society
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• v.13 no.2
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• pp.249-257
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• 2010

The emerging ubiquitous environment is improving IT technologies and the popularization of broadband Internet is encouraging creation and sharing of various contents. The contents include the concept of production and circulation of digital information/contents, in forms of characters, codes, voices, sounds, client and videos for being used on the Internet and networks. The contents are widely shared in networks and users can have a wide range of knowledge and gain the freedom of presentation from them. So now users participations are augmented gradually. However, many contents without acquiring agree of copyright are sharing on the Internet, so many problems happen in the manufacturing process of digital contents. To solve this problem, many research projects to limit contents utilization onto legitimate users and to provide secure contents protection and download, are in progress. Therefore, in this paper, we propose a secure D-CAS system (SDCS) which provides security for contents downloading.

• Journal of Convergence for Information Technology
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• v.8 no.1
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• pp.37-42
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• 2018

This study focuses on investigating and comparing the lengths of the five words, vowels, and the ratio of the length of vowels to that of words among the Korean college students with the English native speaker. English sentences were read and recorded by Korean subjects to do this experiment. The vowel lengths were measured from a sound spectrogram, the Praat software program, and these data were analyzed through statistical analysis. I could easily tell that there were differences between the groups and they were significant. In the English front low vowel /${\ae}$/, I was able to find out that native subjects pronounced differently from Korean subjects, and the differences were significant. However, the pronunciation of the English diphthong /ai/, native subjects pronounced significantly shorter than Korean subjects.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.2
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• pp.355-361
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• 2013

Various study for technology of agmented reality by using mobile has been progressed in aspect of advantages for mobility and popularity, recently as technology of agmented reality is developing day by day. Mobile agmented reality is technology imaginary informations are grafted into reality by using mobile. That can induce new learning experience showing high interest and interesting for infant education. This thesis is a fishes encyclopedia for infant that was made by displaying pictures as 3D fish model. 3D fish model is possible to turn on the six axis and enlarge and reduce by demand of users. Furthermore, it was made for inducing interesting about book for infant by inserting various sound effect. The resort of using system for infant shows interest and interesting over four times in case infant will learn with fishes encylopedia not previous books.

• The Journal of the Acoustical Society of Korea
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• v.13 no.2E
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• pp.26-31
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• 1994

A new feature extraction technique utilizing strange attractor and artificial neural network for speaker recognition is presented. Since many signals change their characteristics over long periods of time, simple time-domain processing techniques should e capable of providing useful information of signal features. In many cases, normal time series can be viewed as a dynamical system with a low-dimensional attractor that can be reconstructed from the time series using time delay. The reconstruction of strange attractor is described. In the technique, the raw signal will be reproduced into a geometric three dimensional attractor. Classification decision for speaker recognition is based upon the processing or sets of feature vectors that are derived from the attractor. Three different methods for feature extraction will be discussed. The methods include box-counting dimension, natural measure with regular hexahedron and plank-type box. An artificial neural network is designed for training the feature data generated by the method. The recognition rates are about 82%-96% depending on the extraction method.