• Proceedings of the IEEK Conference
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• summer
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• pp.249-253
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• 2004

Wavelet transform (WT) has attracted most engineers and scientists because of its excellent properties. The coherence of practical approach and a theoretical basis not only solves currently important problems, but also gives the potential of formulating and solving completely new problems. It has been show that multi-resolution analysis of Wavelet transforms is good solution in speech analysis and threshold of wavelet coefficients has near optimal noise reduction property for many classes of signals. This paper proposed applications of wavelet in speech processing: pitch detection, voice-unvoice (V -UV) decision, denoising with the detailed algorithms and results.

• Journal of Information Processing Systems
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• v.18 no.3
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• pp.402-410
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• 2022

Digital data can be manipulated easily, so information related to the timestamp is important in establishing the reliability of the data. The time values for a certain file can be extracted following the analysis of the filesystem metadata or file internals, and the information can be utilized to organize a timeline for a digital investigation. Suppose the reversal of a timestamp is found on a mobile device during this process. In this case, a more detailed analysis is required due to the possibility of anti-forensic activity, but little previous research has investigated the handling and possible manipulation of timestamps on mobile devices. Therefore, in this study, we determine how time values for multimedia files are handled according to the operating system or filesystem on mobile devices. We also discuss five types of timestamps-file created (C), last modified (M), last accessed (A), digitalized (Di), and filename (FN) of multimedia files, and experimented with their operational features across multiple devices such as smartphones and cameras.

• Journal of Korea Multimedia Society
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• v.19 no.9
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• pp.1738-1746
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• 2016

This study is on moving images among the various media created by the screen-based image media in the multimedia age. Moving images shown in the image media are reinterpreted in various forms and are necessary to have a conceptual definition as expression media to meet the changes. Therefore, the study identified the conceptual definition of moving images from the perspective of objects, and subdivided them into the visual cognitive area to satisfy the recent characteristics of visual media. It also suggested the guidelines required for analyzing the image media based on the results of the case analysis of 8 different works.

• Proceedings of the Korean Society of Computer Information Conference
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• 2020.07a
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• pp.351-353
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• 2020

본 논문에서는 우리나라에 있는 탑들이 손실된 경우가 많은데 탑의 손실된 부분을 복원하기 위한 방법을 제안한다. 우리나라에 존재하는 탑들은 보존이 잘 돼있는 것보다 안 돼있는 것이 많다. 손실된 탑들을 이미지 객체로 인식시킬 시에 GAN, DCGAN, SDADE등의 알고리즘과 기존의 연구 결과들을 적용시켜 보다 효과적인 방법을 찾는 것을 제안한다.

• Journal of information and communication convergence engineering
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• v.2 no.3
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• pp.139-144
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• 2004

In order to transmit various types of multimedia data (i.e. voice, video, and data) over a wireless channel, the coding and modulation scheme needs to be flexible and capable of providing a variable quality of service, data rates, and latency. In this paper, we study a mobile multimedia COMA network combined with the concatenated Reed-Solomon/Rate Compatible Punctured Convolution code (RS/RCPC). Also, this paper propose the combination of concatenated RS/RCPC coder and COMA RAKE receiver for multimedia COMA traffic which can be sent over wireless channels. From the results, using a frequency selective Rayleigh fading channel model, it is shown that concatenated RS/RCPC coder at the wireless physical layer can be effective in providing reliable wireless multimedia CDMA network. And the proposed scheme that combine concatenated RS/RCPC coder and CDMA RAKE receiver provides a significant gain in the BER performance over multi-user interference and multipath frequency selective fading channels.

• Journal of Korea Multimedia Society
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• v.25 no.2
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• pp.197-205
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• 2022

The Cyber Physical System(CPS) is an important concept in achieving SMSs(Smart Manufacturing Systems). Generally, CPS consists of physical and virtual elements. The former involves manufacturing devices in the field space, whereas the latter includes the technologies such as network, data collection and analysis, security, and monitoring and control technologies in the cyber space. Currently, all these elements are being integrated for achieving SMSs in which we can control and analyze various kinds of producing and diagnostic issues in the cyber space without the need for human intervention. In this study, we focus on implementing a production equipment monitoring system related to building a SMS. First, we describe the development of a fog-based gateway system that links physical manufacturing devices with virtual elements. This system also interacts with the cloud server in a multimedia network environment. Second, we explain the proposed network infrastructure to implement a monitoring system operating on a cloud server. Then, we discuss our monitoring applications, and explain the experience of how to apply the ML(Machine Learning) method for predictive diagnostics.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.711-712
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• 2008

We developed a XMAS (X Multimedia Analysis System) for analyzing the illegal and objectionable multimedia in Internet environment based on Web2.0. XMAS uses the MPEG-7 visual descriptor and multi-class SVM (support vector machine) and its performance (accuracy on precision) is about 91.6% for objectionable multimedia analysis and 99.9% for illegal movie retrieval.

• Proceedings of the Korea Multimedia Society Conference
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• 2012.05a
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• pp.393-393
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• 2012

• Proceedings of the Korean Society of Computer Information Conference
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• 2021.07a
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• pp.253-255
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• 2021

현재 코로나 사태로 비대면으로 진행이 되어 온라인 쇼핑 시장이 지속적으로 증가하고 있고, 4차 산업혁명으로 새로운 혁신 기술로 가상현실(VR)과 증강현실(AR)이 있으며, 좀 더 빠르게, 좀 더 편리하게 할 수 있어 생산성을 향상시키고 있다. 이에 본 논문은 쇼핑몰에 증강현실(AR)기술을 부합하여 사용자들에게 AR 카메라를 활용한 체형 측정 서비스, AR기술을 통해 자신 아바타에 입혀주는 피팅서비스를 통해 사용자들에게 빠르고 편리하게 맞춤형 쇼핑을 제공한다. 구현은 현재 사용 중인 운영체계 중 Android와 Ios 사용하고 있는 ARKit와 ARCore를 활용을 하여 구현한다.

• Journal of the Korea Society for Simulation
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• v.15 no.2
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• pp.23-29
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• 2006

This paper studies the Internet stream server which serves multimedia stream services such as VoD and MoD. The Internet multimedia stream server is developed to provide 50 users with continuous multimedia stream contents simultaneously. This paper focuses on introducing design concepts, operation details and on evaluating system performance and doing sensitivity analysis with respect to the change of the system components. The performance evaluation is performed using simulation in order to identify the system component that mostly affects the system performance. The sensitivity analysis shows the service delay rates of the multimedia stream server depending on the user's service request pattern. Also, the analysis is made on the utilization rates of the core system components such as the PCI bus and the Ethernet card, and on the system performance change by adding more system components.