• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.27 no.1
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• pp.43-50
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• 2017

Acoustic tiles are typically installed on the surface of pressure vessels in submarines to minimize echoes based on the ship's own noise and active sonar. In this study, we studied low frequency active echo reduction techniques to reduce underwater target echo signals. Active control algorithms using tile type projectors and FxLMS logic have been developed and the projectors have been installed in the assumed hull structure. The effectiveness of projectors and control algorithms has been evaluated in time and frequency domain analysis through experiments in the tank.

• Journal of Multimedia Information System
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• v.2 no.1
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• pp.187-192
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• 2015

The aim of this study was to develop and analyze a short course educating App Inventor and Arduino that showed the importance of software for youth. The course consists of a total of 10 missions for a 4 hour course divided into 2 parts, each 2 hours respectively. We conducted a basic course of Arduino for hardware and software, Processing for server programming, and App Inventor for programming for smartphones. The final mission was to send a signal to a server with a smartphone and to control light connected to a relay which passes Arduino connected with a server and serial communication. Participants completed 95% of missions, and we found the course had an educational effect for improving creativity and realization of software importance.

• Proceedings of the Korea Information Processing Society Conference
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• 2019.05a
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• pp.721-722
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• 2019

본 연구는 외부 환경 제어를 위해 안정적인 뇌파 신호를 추출하기 위한 알고리즘을 제안한다. 본 알고리즘은 다중 회귀의 원리를 사용한 머신러닝을 통하여 뇌파의 경향성을 분석하여, 측정 시 발생할 수 있는 불안정한 노이즈를 필터링하고, 제어 신호를 빠른 시간 안에 판단하는 것을 목적으로 한다. 측정은 CZ 측정 위치에서 1 채널의 EEG 기기로 이루어진다. 본 연구를 바탕으로 BCI 분야에서 효과적으로 외부 디바이스 제어를 위한 입력 신호를 추출하는 방법이 될 수 있을 것으로 예상한다.

• Journal of Korea Multimedia Society
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• v.9 no.12
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• pp.1580-1587
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• 2006

The term molecular imaging can be broadly defined as the in vivo characterization and measurement of biologic processes at the cellular and molecular level. Optical imaging that has highly reproducibility and repetition used in molecular imaging research. In the bioluminescence imaging, animals carrying the luciferase gene are imaged with a cooled CCD(Charge-Coupled Device) camera to pick up the small number of photons transmitted through tissues. Molecular imaging analysis will allow us to observe the incipience and progression of the disease. But hardware device for molecular imaging and software for molecular image analysis were dependent on imports. In this paper, we suggest image processing methods and designed software for bioluminescence signal analysis. And we demonstrated high correlation(r=0.99) between our software's photon counts and commercial software's photon counts. ROI function and processing functions were accomplished without error. This study have the importance of the development software for bioluminescence image processing and analysis. And this study built the foundations for creative development of analysis methods. We expected this study lead the development of image technology.

• ETRI Journal
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• v.22 no.1
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• pp.20-29
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• 2000

In this paper, we present a design of video and audio single chip encoder/decoder for portable multimedia application. The single-chip called as video audio signal processor (VASP) consists of a video signal processing block and an audio single processing block. This chip has mixed hardware/software architecture to combine performance and flexibility. We designed the chip by partitioning between video and audio block. The video signal processing block was designed to implement hardware solution of pixel input/output, full pixel motion estimation, half pixel motion estimation, discrete cosine transform, quantization, run length coding, host interface, and 16 bits RISC type internal controller. The audio signal processing block is implemented with software solution using a 16 bits fixed point DSP. This chip contains 142,300 gates, 22 Kbits FIFO, 107 kbits SRAM, and 556 kbits ROM, and the chip size is $9.02mm{\times}9.06mm$ which is fabricated using 0.5 micron 3-layer metal CMOS technology.

• Journal of the Institute of Convergence Signal Processing
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• v.3 no.2
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• pp.1-7
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• 2002

Since multimedia data such as video and audio data are displayed within a certain time constraint, their computation and manipulation should be handled under limited condition. Traditional real-time scheduling algorithms could not be directly applicable, because they are not suitable for multimedia scheduling applications which support many clients at the same time. Rate Regulating Proportional Share Scheduling Algorithm is a scheduling algorithm considered the time constraint of the multimedia data. This scheduling algorithm uses a rate regulator which prevents tasks from receiving more resource than its share in a given period. But this algorithm loses fairness, and does not show graceful degradation of performance under overloaded situation. This paper proposes a new modified algorithm, namely Modified Proportional Share Scheduling Algorithm considering the characteristics of multimedia data such as its continuity and time dependency. Proposed scheduling algorithm shows graceful degradation of performance in overloaded situation and the reduction in the number of context switching. Furthermore, a new evaluation method is proposed which can evaluate the flexibility of scheduling algorithm.

• Journal of the Institute of Convergence Signal Processing
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• v.1 no.1
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• pp.64-73
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• 2000

The Korean character recognition technology for user interface in multimedia terminal requires fast processing time and high recognition rate. In this paper, we propose an phoneme and character recognition technology which uses characteristic information of korean and features of input strokes, i.e, feature point, feature vector, virtual vector, position relation between strokes. And, a recognition both phoneme and character by the various writing types of users uses korean database. The Korean database has been constructed by the characteristic information of korean and phoneme models which have various stroke information. Also, we use successive processing by the position relation between strokes and backtracking processing by the modification processing of stroke numbers which composed of each phoneme. This method reduces the complex processing of phoneme separation. The proposed on-line korean character recognition system has obtained 13msec average character processing time and correct recognition rate more than $95{\%}$ In a recognition experiment, where we tested 600 characters written by 10 people among 1,200 words.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.42 no.1
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• pp.95-100
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• 2005

This paper proposes a DVS method which effectively reduces the power consumption of multimedia signal processor. Analytic derivations of effective range of its power saving factor are obtained with the assumption of a Gaussian distribution for the frame-based computational burden of the multimedia processor. A closed form equation of the power saving factor is derived in terms of the mean-standard deviation of the distribution. An MPEG-2 video decoder algorithm and AAC encoder algorithm are tested on ARM9 RISC processor for the experimental verification of the power saying of the proposed DVS approach. The experimental results with diverse MPEG-2 video and audio files show 50～30% power saving factor and show good agreement with those of the analytically derived values.

• The Transactions of the Korea Information Processing Society
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• v.7 no.3
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• pp.901-908
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• 2000

Satellite communication in the 21 century's high tech information world is developing rapidly, marked by high levels of applications and functions. For example, satellite communication can process and switch the speed of the service provided by a broad and vast digital multimedia system such as a long-distance all between nations or broadcasting transfer service, which is supplied by a contemporary satellite system. So, it bring about problems which lack of satellite orbit and gibes out frequency resource by increment of satellite universally. To support this, an OBP satellite system is need, which includes an on-board IF/RF switch, baseband signal processing, multi-beam antenna technology, as well as a simple transponder system. In this paper, we have outlined the next generation of satellite communication; satellite OBP transport network architecture, which offers multimedia service and applied frequency reuse method for multi-spot beam. The satellite B-ISDN transport network architecture is also analyzed.

• Journal of Multimedia Information System
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• v.7 no.3
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• pp.221-230
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• 2020

Used optimization techniques as solution for mobile network have been implemented as a reference systems for various applications against fading and signals perturbation, in addition each transition to 5th generation telecommunication standards require a deep studies in order to park an applied instantaneous process. The paper describes a preliminary planning and a careful preparation to update both subscriber radio access network as well as data transmission network this approach conducts to make network resource updates invisible for customers and with minimal costs for mobile operators basically in terms of delay. In addition, network operators transit to mobile networks, multimedia services efficient delivery are considered the challenging application and the most promising for mobile network operators today, this work conduct to optimize video consumption of mobile users which are exponentially increasing. The interference is a complex phenomenon in mobile radio telecommunication system, and a mobile phone can be a source of interference to another one. Actual advances in technology necessitate the need for the complicated software solution that can take several unexpected phenomena in consideration to rise to a level higher than ever. The capability needs today require the use of Drive test which is used to take the performance of network in the field by using a special software called TEMS investigation, it have been implemented as standalone systems for various applications. The paper focuses on considering as the best technical for optimization of mobile networks, analysis and processing of signal, a Drive Test is the method used to take the performance of network in the field by using a special software called TEMS investigation. Most used in the world, this software is reputed to detect and analyze many problems of mobile network between the mobile phone and the transmitter: BTS in case of GSM and Node B for UMTS. An example of that is interference in radio communication. It exists permanently and it degrades considerably the quality of received signal when it exceeds certain levels.