• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 1999.04b
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• pp.296-301
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• 1999

Different papers such as toilet and towel tissue, newsprint and copy paper made from reclaimed fibres were characterized using UV-VIS reflectance and fluorescence spectroscopy. The emission properties of the extracts of the papers were also evaluated. Photochemical irradiation at ambient temperatures, and thermal aging of the copy papers at 105$^{\circ}C$ and 150$^{\circ}C$ were performed. Post-colour numbers (PC) were calculated from the reflectance values measured from the corresponding UV-VIS reflectance spectra. Light absorption coefficient spectra were calculated before and after irradiation, and the changes in absorption coefficient were related to the content of chromophores in the papers. Photochemical and thermal discolouration of the copy papers, similar to that of virgin fibres, was readily observed. The influence of changes in the concentrations of fluorescent brightening agents and dyes on the spectral properties was also assessed. Photostabilization studies of the copy papers were performed with the use of polymer additives polyethylene glycol (PEG) and polytetrahydrofuran (PTHF).

• Journal of KIISE:Software and Applications
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• v.30 no.5_6
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• pp.497-502
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• 2003

Content-based video copy detection is a complementary approach to watermarking. As opposed to watermarking, which relies on inserting a distinct pattern into the video stream, video copy detection techniques match content-based signatures to detect copies of video. Existing typical content-based copy detection schemes have relied on image matching which is based on key frame detection. This paper proposes a motion directional histogram, which is quantized and accumulated the direction of motion, for video copy detection. The video clip is represented by a motion directional histogram as a 1-dimensional graph. This method is suitable for real time indexing and counting the TV CF verification that is high motion video clips.

• Journal of Korea Multimedia Society
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• v.7 no.8
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• pp.1058-1065
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• 2004

Embedded system is widely used in various applications from simple monitor to a set-top box with CPU, memory and hard disk drives. Specially, embedded OS is ported in moveable or small machinery since it ordinarily transmits multimedia data. In this paper, we propose Null copy scheme on the embedded linux system for multimedia service, which can reduce memory copy overhead from user address space to kernel one, and vice versa. Since embedded system for networked multimedia service has low level computing power as well as memory, the Null copy scheme can provide more improved QoS. Our image transmission experiment results on embedded linux target board(CPU utilization an Deadline miss rates) installed a web camera have shown that the proposed scheme can increase fast response and lower CPU overhead.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.6
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• pp.1133-1144
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• 2021

Zero-copy is a technology that is also called no-memory copy, and through its use, context switching between the user space and the kernel space can be reduced to minimize the load on the CPU. However, this technology is only used to transmit small random files, and has not yet been widely used for large file transfers. This paper intends to discuss the practical application of zero-copy in processing large files via a network. To this end, we first developed a small test bed and program that can transmit and store data based on zero-copy. Afterwards, we intend to verify the usefulness of the applied technology in detail through detailed performance evaluation

• Journal of the Korea Society of Computer and Information
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• v.15 no.2
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• pp.19-26
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• 2010

The Windows registry is a hierarchical database where the configuration data of a system or application programs is stored. In this paper, we presented and implemented a registry virtualization algorithm and measured its performance. The registry virtualization algorithm presented in the paper is called Copy-One-level On Write-Open(COOWO) that is a modified version of general Copy On Whte(COW) method to make it suitable for registry virtualization. In this paper, we implemented the proposed algorithm as a dynamically loadable library in Windows and applied it to many Windows application programs. This paper is meaningful since we described a registry virtualization algorithm in detail in situation where we can not find papers that describe the registry virtualization in detail, and we could find the performance of the algorithm can be used in the real applications.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.10
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• pp.3520-3537
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• 2014

Video copy detection methods have emerged in recent years for a variety of applications. However, the lack of efficiency in the usual retrieval systems restricts their use. In this paper, we propose a parallel implementation strategy for content based video copy detection (CBCD) by using a multi-core processor. This strategy can support video copy detection effectively, and the processing time tends to decrease linearly as the number of processors increases. Experiments have shown that our approach is successful in speeding up computation and as well as in keeping the performance.

• Journal of Korea Multimedia Society
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• v.16 no.4
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• pp.411-417
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• 2013

In this paper, we proposed a fast detection method of copy-move forgery image based on low frequency coefficients of the DCT coefficients. We proposed a new matching criterion of copy-moved forgery image detection (MCD) using discrete cosine transform. For each $8{\times}8$ pixel block, the DCT transform is calculated. Our algorithm uses low frequency four (DC, 3 AC coefficient) and six coefficients (DC, 5 AC coefficients) of DCT per $8{\times}8$ pixel block. Our algorithm worked block matching for DCT coefficients of the $8{\times}8$ pixel block is slid by one pixel along the image from the upper left corner to the lower right corner. Our algorithm can reduce computational complexity more than conventional copy moved forgery detection algorithms.

• Korean Journal of Computational Design and Engineering
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• v.13 no.4
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• pp.273-285
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• 2008

In this paper we propose an engineering bill of materials (E-BOM) copy method that can be utilized to manage the product information for each equipment during building a product lifecycle management (PLM) system in the order-specific semiconductor equipment manufacturer. The previous works studied on an E-BOM creation and management method for the mass manufacturing and production. The method is difficult to apply to an environment in which many engineering changes occur and the different specification to each equipment is required such as semiconductor equipments and facilities adopting built-to-order instead of built for inventory. Moreover the method is known to be the major drawback to deteriorate the design efficiency. Our E-BOM copy method enables users efficiently to manage the specification of a product and shortens the product development cycle. To implement the E-BOM copy method in the PLM environment, we developed the E-BOM copy system that automatically generates new parts and their numbers according to the numbering rule while copying the E-BOM from existing semiconductor equipments and then can apply the parts for reuse to new semiconductor equipments. This system can duplicate not only 3D CAD data but also technical documents.

• Journal of Information Processing Systems
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• v.14 no.1
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• pp.6-31
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• 2018

With the rapid development of the science and technology, it has been becoming more and more convenient to obtain abundant information via the diverse multimedia medium. However, the contents of the multimedia are easily altered with different editing software, and the authenticity and the integrity of multimedia content are under threat. Forensics technology is developed to solve this problem. We focus on reviewing the blind image forensics technologies for copy-move forgery in this survey. Copy-move forgery is one of the most common manners to manipulate images that usually obscure the objects by flat regions or append the objects within the same image. In this paper, two classical models of copy-move forgery are reviewed, and two frameworks of copy-move forgery detection (CMFD) methods are summarized. Then, massive CMFD methods are mainly divided into two types to retrospect the development process of CMFD technologies, including block-based and keypoint-based. Besides, the performance evaluation criterions and the datasets created for evaluating the performance of CMFD methods are also collected in this review. At last, future research directions and conclusions are given to provide beneficial advice for researchers in this field.

• IEMEK Journal of Embedded Systems and Applications
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• v.17 no.6
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• pp.309-317
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• 2022

In this paper, we propose a machine learning-based copy-move forgery detection network with dual branches. Because the rotation or scaling operation is frequently involved in copy-move forger, the conventional convolutional neural network is not effectively applied in detecting copy-move tampering. Therefore, we divide the input into rotation-invariant and scaling-invariant features based on the wavelet coefficients. Each of the features is input to different branches having the same structure, and is fused in the combination module. Each branch comprises feature extraction, correlation, and mask decoder modules. In the proposed network, VGG16 is used for the feature extraction module. To check similarity of features generated by the feature extraction module, the conventional correlation module used. Finally, the mask decoder model is applied to develop a pixel-level localization map. We perform experiments on test dataset and compare the proposed method with state-of-the-art tampering localization methods. The results demonstrate that the proposed scheme outperforms the existing approaches.