• 한국염색가공학회:학술대회논문집
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• 한국염색가공학회 2007년도 추계학술발표회
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• pp.139-140
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• 2007

• 한국염색가공학회:학술대회논문집
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• 한국염색가공학회 2007년도 추계학술발표회
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• pp.141-142
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• 2007

• 한국염색가공학회:학술대회논문집
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• 한국염색가공학회 2007년도 추계학술발표회
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• pp.143-144
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• 2007

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 하계종합학술대회논문집
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• pp.847-850
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• 1998

One of the most difficult problem of designing VLSI is a mixed-circuit design, that is to design circuit containing both analog parts and digital parts. Digital to analog converter and analog to digital converter is a typical case. Especially it can be a serious problem when mixed circuit are put into a large digital circuit like microcontroller. However nowadays this problem is settled by separating analog circuit parts outside the IC. This technique is based on converting a digital signal into a pulse sequence. Then an analog signal is obtained by averaging this pulse sequence at the external low-pass filter. An anlog to digital converter is designed using a stochastic logic instead of a traditional PWM (pulse-width modulation) signal and ins implemente dusing FPGa. Stochastic pulse sequence can be made as a simple circuits and moreover can be mathematically processed by simple circuits -AND gates. The spectral property of stochastic pulse sequence method is better than that of PWM method. So it make easy to design a external low-pass filter. This technique has important advantages, especially the reduction of the ADC cost.

• 한국BIM학회 논문집
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• 제10권4호
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• pp.11-21
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• 2020

With increasing interest and research on smart cities, there is also an increasing number of studies on urban facilities that can be built within smart cities. According to these studies, smart cities' urban facilities are likely to become high value-added industries. However, the concept of smart city is not clear because it involves various fields. Therefore, in this study, the definition of Next-Generation(N.G) Smart City Facilities with Digital Twin and Digital Chain is carried out through a multidisciplinary approach. Based on this, Next-Generation Smart City Facilities will be divided into High Value-Added Products and Big Data Platforms. Subsequently, the definition of the Digital Chain containing the data flow of the entire process built through the construction of the Digital Twin proceeds. The definitions derived are applied to the Next-Generation Noise Barrier Tunnel to ensure that data is exchanged at the Digital Twin stage, and to review the proposed configuration of the Digital Chain and Data Flow in this study. The platform definition and Digital Chain of Next-Generation Smart City Facilities proposed in this study suggest that it can affect not only the aspects of data management that are currently in the spotlight, but also the manufacturing industry as a whole.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2007년도 학술대회
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• pp.142-146
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• 2007

Digital Rights Management (DRM) technology has been widely used for protecting the digital contents over the recent years. But the digital contents protected by DRM are vulnerable to various video memory capture programs when DRM packaged contents are decrypted on the consumers' multimedia devices. To make up for this kind of DRM security holes the Forensic Marking (FM) technology is being deployed into the content protection area. Most leading DRM companies as well as big electronics companies like Thomson and Philips already have commercial FM solutions. Forensic Marking technology uses the digital watermarking to insert the user information such as user id, content playing time and etc. into the decrypted and decoded content at the playback time on the consumer devices. When the content containing watermarked user information (Forensic Mark) is illegally captured and distributed over the Internet, the FM detection system takes out the inserted FM from the illegal contents and informs contents service providers of the illegal hacker's information. In this paper the requirements and test conditions are discussed for the commercial Forensic Marking systems.

• 디지털산업정보학회논문지
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• 제11권2호
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• pp.73-90
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• 2015

When we apply file commands on files in a directory, the directory as well as the file suffer changes in timestamps of MFT entry. Based on understanding of these changes, this work provides a digital forensic analysis on the timestamp changes of the directory influenced by execution of file commands. NTFS utilizes B-tree indexing structure for managing efficient storage of a huge number of files and fast lookups, which changes an index tree of the directory index when files are operated by commands. From a digital forensic point of view, we try to understand behaviors of the B-tree indexes and are looking for traces of files to collect information. But it is not easy to analyze the directory index entry when the file commands are executed. And researches on a digital forensic about NTFS directory and B-tree indexing are comparatively rare. Focusing on the fact, we present, in this paper, directory timestamp changes after executing file commands including a creation, a copy, a deletion etc are analyzed and a method for finding forensic evidences of a deletion of directory containing files. With some cases, i.e. examples of file copy and file deletion command, analyses on the problem of timestamp changes of the directory are given and the problem of finding evidences of a deletion of directory containging files are shown.

• Journal of Korean Society for Atmospheric Environment
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• 제23권E2호
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• pp.66-73
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• 2007

The introduction of tracer gas techniques to ventilation studies in indoor environments provides valuable information that used to be unattainable from conventional testing environments. Data acquisition systems (DASs) containing analogue-to-digital (A/D) converters are usually used to function the key role that records signals to storage in digital format. In the testing process, there exist a number of components in the measuring equipment which may produce system-based inference to the monitored results. These unwanted fluctuations may cause significant error in data analysis, especially when non-linear algorithms are involved. In this study, a pre-processor is developed and applied to separate the unwanted fluctuations (noise or interference) in raw measurements and to reduce the uncertainty in the measurement. Moving average, notch filter, FIR (Finite Impulse Response) filters, and IIR (Infinite Impulse Response) filters are designed and applied to collect the desired information from the raw measurements. Tracer gas concentrations are monitored during leakage and ventilation tests in the model test room. The signal analysis functions are introduced to carry out the digital signal processing (DSP) work. Overall the FIR filters process the $CO_2$ measurement properly for ventilation rate and mean age of air calculations. It is found that, the Kaiser filter was the most applicable digital filter for pre-processing the tracer gas measurements. Although the IIR filters help to reduce the random noise in the data, they cause considerable changes to the filtered data, which is not desirable.

• 정보보호학회논문지
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• 제24권5호
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• pp.851-860
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• 2014

IT 기술의 발달과 사용자 편의를 증대시키는 전자제품에 대한 수요가 증가함에 따라 기존의 디지털 TV에 네트워크 기능을 추가하여 사용자에게 다양한 서비스를 제공하는 스마트 TV가 활발하게 개발되어 보급되고 있다. 이러한 TV 기능의 변화는 디지털 포렌식적으로 의미를 갖는다. 기존의 디지털 TV는 기기 안에 저장되는 데이터가 충분하지 않아 디지털 포렌식 조사의 대상으로 주목받지 못하였다. 하지만 스마트 TV는 사용자에게 다양한 기능과 편리한 사용을 제공하기 위해 사용자의 과거 행동을 파악할 수 있는 데이터를 기기 내부에 저장하기 때문에 디지털 포렌식 조사의 대상으로 가치가 있다. 본 논문은 디지털 포렌식의 한 분야로서 기존의 디지털 포렌식보다 폭넓은 연령대의 사용자 행동을 추적할 수 있는 스마트 TV 포렌식의 개념 및 방법을 제안한다.

• 한국멀티미디어학회논문지
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• 제22권2호
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• pp.322-333
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• 2019

After the launch of smart phones, various miniaturized smart devices such as wearable and IOT devices have deeply embedded in human life, and have created a technology-oriented society. In this technology-oriented society, technology development itself is important, however it seems more important to utilize existing technology appropriately and deliver effectively to human life. As the computer became personalized after the appearance of PC, human-centered computing such as HCI and UCD had begun to appear. However, most of the researches focused on technology that made human being convenient to interact with computer such as computer systems design and UX development. In the technology-oriented society, it seems more urgent to apply existing technology to human life. In this paper, we propose a methodology, 'Digital Leveraging' which guides how to effectively apply technology to human life. Digital Leveraging is the way of convergence between technology and humanities.