• The KIPS Transactions:PartD
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• v.9D no.5
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• pp.925-930
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• 2002

This paper discusses techniques for embedding data into 3D polygonal models of geometry. Much researches of Watermarking had been gone as element technology of DRM (digital rights management). But, few research had gone to 3D polygonal model. Most research is limited at text document, 2D image, animation, music etc. RP system is suitable a few production in various goods species, and it is used much in industry to possible reason that produce prototype and find error or incongruent factor at early stage on design in product development childhood. This paper is research about method that insert watermark in STL ( stereolithography) file that have 3D shape model. Proposed algorithm inserts watermark in normal vector region and facet's interior region of 3D shape data. For this reason, 3D shape does not produce some flexure and fulfill invisibility of watermark. Experiment results that insert and extract watermark in normal netter region and facet's Interior region of 3D shape data by proposed algorithm do not influence entirely in 3D shape and show that insertion and extraction of watermark are possible.

• The Journal of the Acoustical Society of Korea
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• v.37 no.5
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• pp.363-368
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• 2018

Recently a slat type ceiling is widely used in various spaces, such as music performance spaces and concourse of airport and a general reception area of a building. However, it is hard to find a proper design guideline or material useful in designing such spaces, due to the lack of relevant researches on the effect of a slat ceiling on room acoustics. The present work investigated the effect of a slat type ceiling using a physical scale model method. A 1/20 scale model of a small shoe-box type music performance hall was built and a slat ceiling with different configurations was installed. 6 cases of different ceiling configurations were considered with the combination of 2 slat ceiling height cases and 3 distance cases between slats. The effect of a slat ceiling on the acoustics of a room was evaluated by measuring reverberance($T_{30}$), intelligibility and clarity($D_{50}$ and $C_{80}$), and loudness(G and $G_{80}$).

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.30 no.2
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• pp.169-172
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• 2019

Frequency-modulated continuous wave(FMCW) radars with array antennas are widely used because of their light weight and relatively high resolution. A usual approach for the joint range and angle estimation of a target using an array FMCW radar is to create a range-angle matrix with the deramped received signal, and subsequently apply two-dimensional(2D) frequency estimation methods such as 2D fast Fourier transform on the range-angle matrix. However, such frequency estimation approaches cause bias errors since the frequencies in the range-angle matrix are not independent. Therefore, we propose a new maximum likelihood-based algorithm for joint range and angle estimation of targets using array FMCW radar, and demonstrate that the proposed algorithm achieves the Cram?r-Rao bounds, both for range as well as angle estimation.

• Journal of the Korea Society of Computer and Information
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• v.19 no.2
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• pp.57-65
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• 2014

The role of sound in producing 3D animation clip is one of the important factor to maximize the immersive effects of the scene. Especially interaction between video and sound makes the scene expressions more apparent, which is diversely applied in video production. One of these interaction techniques, the out-focussing technique is frequently used in both real video and 3D animation field. But in 3D animation, out-focussing is not easily implemented as in music videos or explosion scenes in real video shots. This paper analyzes the sound data to synchronize the depth of field with it. The novel out-focussing technique is proposed, where the object's field of depth is controlled by beat rhythm in the sound data.

• Journal of Digital Contents Society
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• v.5 no.4
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• pp.300-305
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• 2004

The industry of digital culture contents has resulted in the high growth of added value at the area of game and movie in 2004 but the markets of animation character, and music disc have been weaken. Animation industries in Digital culture contents have attracted the attention of the people as the business of multi culture contents which has the possibility to expend and to enhance the added value nut only for the field of image and character business but also for the area of the copy right on. The stable structure of market, however, has not been settked down except a few of successful projects due to the rapid decline of 2D animation and the strong market of 3D in overseas. The purpose of this study is to analyze and research the basic logic of the market structure at the domestic business of 3D animation. In addition this paper is to suggest an alternative in terms of benchmarkin in overseas. It could be expected to achieve the effective production in this field, if the result of this study could be applied to the related world as a development model at the area of 3D animation in digital culture contents.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.8
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• pp.623-628
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• 2013

The retrodirective array antenna system is operated faster than existing techniques of beamforming due to its less complexity. Therefore, it is effective for beam tracking in the environment of fast vehicle. On the other hand, it also has difficulty in estimating AOA according to multipath environment or multiuser signals. To improve the certainty of estimating AOA), this article proposes hybrid digital retrodirective array antenna systme combined with MUSIC algorithm. In this paper, the digital retrodirective array antenna system is designed according to the number of antenna array by using only one digital PLL which finds angle of delayed phase. And we evaluate the performance of the digital retrodirective array antenna for the high speed tracking application. Performance is studied by simulink when the speed of mobile is 300km/h and the distance between transmitter and receiver is 100m and then we have to confirm the performance of the system in multi path environment. As a result, the mean of AOA (Angle Of Arrival) error is $4.2^{\circ}$ when SNR is 10dB and it is $1.3^{\circ}$ when SNR is 20dB. Consequently, the digital RDA shows very good performance for high speed tracking due to the simple calculation and realization.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.27 no.2
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• pp.129-138
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• 2017

The subjective experiments on professional musicians using the four channel real-time convolution system were conducted to investigate the effect of reverberant sound pressure level ($L_{rev}$) for stage acoustics. The strength of $L_{rev}$ was changed to 2 dB steps to investigate the optimal strength for ease of performance and the subjective questionnaire survey was conducted to investigate the effect of subjective factor by $L_{rev}$. From the experimental results, a specific strength of $L_{rev}$ is related to ease of music performance. Loudness and directivity are highly correlated.

• Journal of the Korea Computer Industry Society
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• v.7 no.5
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• pp.573-582
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• 2006

The game is in progress according to the game story with the text, graphic, animation, motion picture, music, etc. Also the result of the game varies depending on the strategy and tactics of the player. For the development of the game, this paper describes the task of the game planner, game programmer, and game graphic designer. Game graphic designers are classified into 4 parts such as the art director, original picture designer, 2D designer, and 3D designer. Among these, the 3D designer makes the 3D game characters with the use of 3D tools. This paper presents the method that 3D designers and beginners can develop 3D characters easily and quickly, Also, this paper shows the method for making preparations of SourceModel which includes 150 polygons. The SourceModel is made up of between five life size and eight life size. In addition, Character Primitives Interface is made to use SourceModel in MaxScript. Accordingly 3D designers have the free use of SourceModel and they will be able to save time.

• Proceedings of the Korea Multimedia Society Conference
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• 2002.11b
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• pp.377-380
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• 2002

멀티미디어 시대에서 중요한 기술 중에 한 부분인 디지털 컨텐츠 제작 및 처리부분이 있을 것이다. 최근 가장 급성장하고 발전하고 있는 인터넷 관련 하드웨어 기술과 소프트웨어 기술에서 디지털 영상을 처리하는 기술은 급격히 증가하고 있으며 이러한 발전은 디지털 사운드 기술개발에도 많은 발전이 필요하고 계속해서 요구되고 있는 실정이다. 인터넷이라는 매체를 통한 디지털 컨텐츠 서비스분야는 급격히 증가하고 있으며 사회에서는 더욱더 좋은 양질의 컨텐츠 서비스를 원하고 있다. 인터넷 사용자들은 2채널 스테레오 음질에서 만족하지 않고 영화에서 느낄 수 있는 입체음향 5.1채널의 고음질을 원하고 있으며 이러한 입체음향을 서비스를 받기 위해서는 하드웨어 시설을 갖추어야 하는 단점이 있다. 이번 입체음향을 구현하는 뮤직뱅크는 하드웨어시설을 최소화한 상태에서 2개의 스피커에서 입체음향을 느낄 수 있는 기술이 될 것이며 양질의 디지털 사운드 서비스에 크게 기여할 수 있는 점이 중요한 목적이라고 하겠다.

• Journal of the Korean housing association
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• v.18 no.5
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• pp.85-91
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• 2007

This is a case study for improving the sound environmental quality of cafeteria in university campus. The purpose of the study is to find out the present condition of physical level, type, and cause of indoor noise of cafeteria in university campus by comparison with a restaurant near campus. Research methods were field survey and questionnaire survey. Field survey was consisted of measurement on equivalent and instant noise level and observation on noise type. Respondents of questionnaire survey were 60 students using subject cafeteria or restaurant. Surveys were carried out in the 8th and in the 14th of December 2005. The results are as follows. 1) Indoor noise levels of the cafeteria were measured as $67.2{\sim}76.6$ (average 73.3) dB(A)Leq5min and $60.3{\sim}90.5$ (average 71.2) dB (A), exceeded the indoor noise recommended value of ASHRAE (American Society of Heating, Refrigerating and Air Conditioning Engineers). But noise levels of the restaurant were $61.6{\sim}70.4$ (average 66.9) dB(A)Leq5min and $59.8{\sim}70.6$ (average 64.9) dB(A). 2) The users's responses on major noise type in the cafeteria were 'noise by handling equipment and tableware', 'noise by moving chairs', and 'talcing noise', but 'taking noise' and 'background music' in the restaurant. 3) It was found that indoor noise level of the cafeteria was caused by sound reflection of finishing materials, noise diffusion by open type kitchen, and dragging noise of movable furniture.