• Journal of the Institute of Electronics Engineers of Korea SP
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• v.39 no.4
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• pp.388-398
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• 2002

Video representation through representative frames (key frames) has been addressed frequently as an efficient way of preserving the whole temporal information of sequence with a considerably smaller amount of data. Such compact video representation is suitable for the purpose of video browsing in limited storage or transmission bandwidth environments. In a case like this, the controllability of the total key frame number (i.e. key frame rate) depending on the storage or bandwidth capacity is an important requirement of a key frame selection method. In this paper, we present a sequential key frame selection method when the number of key frames is given as a constraint. It first selects the desired number of initial key frames and determines non-overlapping initial time intervals that are represented by each key frame. Then, it adjusts the positions of key frames and time intervals by iteration, which minimizes the distortion. Experimental result demonstrates the improved performance of our algorithm over the existing approaches.

• ETRI Journal
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• v.27 no.5
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• pp.595-607
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• 2005

The widespread use of the Internet has led to the problem of intellectual property and copyright infringement. Digital rights management (DRM) technologies have been developed to protect digital content items. Digital content can be classified into static content (for example, text or media files) and dynamic content (for example, VOD or multicast streams). This paper deals with the protection of a multicast stream on set-top boxes connected to an IP network. In this paper, we examine the following design and architectural issues to be considered when applying DRM functions to multicast streaming service environments: transparent streaming service and large-scale user environments. To address the transparency issue, we introduce a 'selective encryption scheme'. To address the second issue, a 'key packet insertion scheme' and 'hierarchical key management scheme' are introduced. Based on the above design and architecture, we developed a prototype of a multicasting DRM system. The analysis of our implementation shows that it supports transparent and scalable DRM multicasting service in a large-scale user environment.

• Korean journal of applied entomology
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• v.57 no.2
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• pp.65-68
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• 2018

Mimemodes cribratus (Reitter) is newly recognized from Korea. The present study includes a redescription, images of habitus and diagnostic characters of the species. In addition, a key to Korean species of Monotomidae is provided.

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.581-582
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• 2005

• Journal of Magnetics
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• v.16 no.4
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• pp.413-416
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• 2011

An array of FeCo nanotubes has been successfully fabricated in the pores of porous anodic aluminum oxide (AAO) templates by wetting templates method. The morphology and structure of the nanotube array were characterized by scanning electron microscopy, transmission electron microscopy and x-ray diffraction. The average diameter of the nanotubes was about 200 nm, and the length was more than 10 ${\mu}m$. Vibrating sample magnetometer and superconducting quantum interference device were used to investigate the magnetic properties of the nanotube array. Interaction between the nanotubes has been found to be demagnetizing as expected and the switching field distribution is broad.

• Journal of Digital Convergence
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• v.12 no.1
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• pp.573-578
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• 2014

Recently as we enter into the world of an aging society, the U-Healthcare service is newly spotlighted. In order to secure this U-Healthcare, a development of security solution that is suitable for the U-Healthcare environment is required. But the U-Healthcare environment is difficult to apply the existing security solution with the lack of standards, a security solution with high completeness was not developed. At this point, in order to structure the safe U-Healthcare environment, a generating method of an encryption key using the body information that helps the effective key management and ensuring the confidentiality of the data is proposed.

• Journal of information and communication convergence engineering
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• v.13 no.4
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• pp.280-285
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• 2015

Double random phase encryption (DRPE) is one of the well-known optical encryption techniques, and many techniques with DRPE have been developed for information security. However, most of these techniques may not solve the fundamental security problem caused by using fixed phase masks for DRPE. Therefore, in this paper, we propose a key phase mask updating scheme for DRPE to improve its security, where a spatial light modulator (SLM) is used to implement key phase mask updating. In the proposed scheme, updated key data are obtained by using previous image data and the first phase mask used in encryption. The SLM with the updated key is used as the second phase mask for encryption. We provide a detailed description of the method of encryption and decryption for a DRPE system using the proposed key updating scheme, and simulation results are also shown to verify that the proposed key updating scheme can enhance the security of the original DRPE.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.5
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• pp.1693-1701
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• 2010

In this paper, requirements of efficient group key creation in multiple hierarchy structure environment with clear distinction of hierarchical roles within organizations are explained and the method of creating a group key that satisfies such requirements is proposed. The proposed method creates the group key through logical sum operation of hierarchy identifier created using uni-directional hash chain and group identifier randomly created according to the access right. The problem of excessive possession of key information by upper group users in the existing static group key creation technique was resolved. At the same time, lower group users were prevented from deducing key information of upper group users. In addition, as a result of comparative analysis performed with an experiment on existing super group key creation technique and multiple hierarchy group key method, the proposed method was found to be equivalent or superior to existing method in terms of various items including the total number of keys created, the number of keys possessed by users, the number of keys used for encoding and decoding of information, and expandability of keys.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.9
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• pp.4477-4481
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• 2016

Purpose: To compare the relative merits of imatinib and allogeneic hematopoietic stem cell transplantation (allo-HSCT) for chronic myelogenous leukemia (CML). Materials and Methods: This cohort study was designed to compare the outcomes of imatinib (n=292) versus allo-HSCT (n=141) for CML, the clinical data of these patients being retrospectively analyzed so as to compare the event free survival (EFS) and overall survival (OS) between these two groups with patients in the chronic phase (CP) and advanced phases, including accelerate (AP) and blast phases (BP). Results: (1) Patients treated with imatinib (278 in the CP) demonstrated superior EFS, OS, 5-year EFS and 5-year OS rates of 88.5% versus 70.0% (P<0.05), 93.2% versus 80.0% (P<0.05), 84% versus 75.0% (P<0.05) and 92% versus 79.0% (P<0.05), respectively, to those treated with allo-HSCT (120 patients in the CP). (2) Both treatments resulted in similar survival, with EFS and OS rates of 42.9% versus 47.6% (P>0.05), 42.9% versus 57.1% (P> 0.05), respectively, for imatinib (14 patients in the AP and BP) and allo-HSCT (21 patients in the AP and BP). Conclusions: Imatinib confers significant survival advantage (EFS and OS) for CML patients with CP compared with allo-HSCT treatment. However, the outcomes are equally good with both treatments in AP and BP patients.

• Journal of Photoscience
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• v.8 no.2
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• pp.71-71
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• 2001