• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2004.11a
• /
• pp.43-46
• /
• 2004

MPEG-21 is an on-progress project of the Moving Picture Expert Group (MPEG) that has been started in many independent parts such as part for standardizing the declaration of a digital item (MPEG-21 Part 2: Digital Item Declaration), right expression language (MPEG-21 Part S: Rights Expression Language), way to process the digital item (MPEG-21 Part 10: Digital Item Processing), etc. All this part is intended to form a framework to enable transparent and augmented use of multimedia resources across a wide range of networks and devices (1). In this paper, we show our research initiative to develop a web-based application that utilized many parts of MPEG-21 technology. The implemented concept uses a digital item and license providers in the server side while the MPEG-21 Conformant application is implemented as a plug-in application that will be downloaded to the user terminal when user accesses the webpage for the frist time. The result of this research shows that with some combination of MPEG-21 parts, we can develop an authorized multimedia delivery and consumption application.

• Journal of the Korean Society of Combustion
• /
• v.21 no.4
• /
• pp.16-22
• /
• 2016

Pressure and temperature variations in a shock tube have been studied numerically by changing the diameter ratio of a driven part to a driver part. There are five cases where the adopted diameter ratios are 40%, 50%, 60%, 80%, and 100% respectively. The diameter of the driver part remains unchanged meanwhile the shock tube driven part diameter increases from 40% to 100% of the driver part. In the 100% ratio case, the driver part and driven parts have the same diameter of 66.9 mm. As the diameter ratio decreases, the pressure in the shock tube and available test time are increased.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.10 no.4
• /
• pp.1944-1956
• /
• 2016

The Digital Video Broadcasting-Common Scrambling Algorithm is an ETSI-designated algorithm designed for protecting MPEG-2 signal streams, and it is universally used. Its structure is a typical hybrid symmetric cipher which contains stream part and block part within a symmetric cipher, although the entropy is 64 bits, there haven't any effective cryptanalytic results up to now. This paper studies the security level of CSA against impossible differential cryptanalysis, a 20-round impossible differential for the block cipher part is proposed and a flaw in the cipher structure is revealed. When we attack the block cipher part alone, to recover 16 bits of the initial key, the data complexity of the attack is O(2^44.5), computational complexity is O(2^22.7) and memory complexity is O(2^10.5) when we attack CSA-BC reduced to 21 rounds. According to the structure flaw, an attack on CSA with block cipher part reduced to 21 rounds is proposed, the computational complexity is O(2^21.7), data complexity is O(2^43.5) and memory complexity is O(2^10.5), we can recover 8 bits of the key accordingly. Taking both the block cipher part and stream cipher part of CSA into consideration, it is currently the best result on CSA which is accessible as far as we know.

• Korean Institute of Interior Design Journal
• /
• v.16 no.3 s.62
• /
• pp.85-92
• /
• 2007

Changing of paradigm at 21Century is changing a part of routine lives and it affects speculation system of recognizing the world. In this society, human is demanded changing of a part and new learning continuously. Like this, a role of individual and a part of various lives by changing of social environment have a close connection each other. In this society, they would need new circumstance of space by method of work. However, what show not necessity improving of work space but changing is the realities of our society. This thesis examine non-territorialization characteristics by focusing on the openness, composition, and flexibility. The working space on 21c head for a non-territorialization and be summarize. decenterial arrangement, increasing of public space and unification of personal work-station. The purpose of this study is to examine the non-territorialization by analysis of 21c working space.

• The Korean Journal of Ecology
• /
• v.19 no.1
• /
• pp.1-7
• /
• 1996

The net primary productivity and potential natural vegetation in the Korean peninsula in the 21st century were estimated by the Miami model and thermal climate, respectively, based on 148 meteorological data sets. In the 21st century, the distribution range of the net primary produtivity in the Korean peninsula was estimated as 1,050 g $DM{\cdot}m^{-2}{\cdot}yr^{-1}~2,050g\;DM\cdot m^-2\cdot yr^{-1}.\; These\; values\; increased\; by\; 200g\; DM\cdot m^{-2}\cdot yr^{-1}\;on\;northern\;part\;and\;400g\; DM\cdot m^{-2}\cdot yr^{-1}$ on southern part compared with that of the present century. The potential natural vegetation in the Korean peninsula in the 21st century will change into the followings:coniferous forest on Mt. Paektu area, deciduous broadleaf forest on northern part, and evergreen broadleaf forset on southern part.

• Communications of the Korean Mathematical Society
• /
• v.21 no.1
• /
• pp.53-64
• /
• 2006

In this paper, we are concerned with the algebraic representation of the quasi-nilpotent part for prehermitian operators on Banach spaces. The quasi-nilpotent part of an operator plays a significant role in the spectral theory and Fredholm theory of operators on Banach spaces. Properties of the quasi-nilpotent part are investigated and an application is given to totally paranormal and prehermitian operators.

• Clinics in Shoulder and Elbow
• /
• v.21 no.4
• /
• pp.177-178
• /
• 2018

• Journal of Korea Multimedia Society
• /
• v.8 no.5
• /
• pp.587-595
• /
• 2005

The vision for MPEG-21 is to define a multimedia framework to enable transparent and augmented use of multimedia resources across a wide range of networks and devices used by different communities MPEG-21 Event Reporting is required within the MPEG-21 Multimedia Framework in order to provide a standardized means for sharing information about Events amongst Peers and Users. There are several Time used in MPEG-21 Event Reporting. In this paper, we analyze and categorize various kinds of Time used in Event Reporting. And we define ERTimeType to be applied for every. Time used in Event Reporting and implement it by XML to support interoperability of standard. The ERTimeType structure we defined is established its objectivity as it is selected to 'ISO/IEC 21000-Part IS: Event Reporting WD 2.0'.

• Development and Reproduction
• /
• v.21 no.1
• /
• pp.63-69
• /
• 2017

On the 15 days after hatching, the larvae was 4.24-5.10 mm (mean $4.66{\pm}2.18mm$) in total length, and the fins of the membrane started to develop into a fan shape and the melanophore was deposited upper the alimentary canal of the abdomen and on the bladder. At 35 days after hatching, the post-larvae formed a branch-shaped melanophore on the head part with a total length of 6.98-12.5 (mean $9.35{\pm}1.71$) mm, formed on the upper and lower parts of the caudal part, formed on the upper and lower parts of the caudal part, and deposited under the head part and abdomen. At 40 days after hatching, the juvenile was 11.3-18.1 (mean $14.9{\pm}1.53$) mm in total length.

• Geomechanics and Engineering
• /
• v.21 no.6
• /
• pp.537-549
• /
• 2020

The presence of cracks changes the water content pattern during seepage through a cracked soil as compared to that of intact soil. In addition, several different crack networks may form in one soil type. These two factors result in a variation of water contents in the soil matrix part of a cracked soil during seepage. This paper presents an investigation of the effect of crack network representation on the water content of the soil matrix part of cracked soil using numerical models. A new method for the numerical generation of crack networks incorporating connections among crack endpoints was developed as part of the investigation. Numerical analysis results indicated that the difference in the point water content was large, whereas the difference in the average water content was relatively small, indicating the uniqueness of the crack network representation on the average water content of the soil matrix part of cracked soil.