• Journal of Computing Science and Engineering
• /
• v.10 no.2
• /
• pp.68-73
• /
• 2016

An efficient texture compression method is proposed based on a block matching process between the current block and the previously encoded blocks. Texture mapping is widely used to improve the quality of rendering results in real-time applications. For fast texture mapping, it is important to find an optimal trade-off between compression efficiency and computational complexity. Low-complexity methods (e.g., ETC1 and DXT1) have often been adopted in real-time rendering applications because conventional compression methods (e.g., JPEG) achieve a high compression ratio at the cost of high complexity. We propose a block matching-based compression method that can achieve a higher compression ratio than ETC1 and DXT1 while maintaining computational complexity lower than that of JPEG. Through a comparison between the proposed method and existing compression methods, we confirm our expectations on the performance of the proposed method.

• 한국정보컨버전스학회:학술대회논문집
• /
• 2008.06a
• /
• pp.141-144
• /
• 2008

According to the degree how the information communication, technology and various basic given conditions are working, most of all enterprises in 21 century are running utilizing information technology. Mongolia is also driving forward for the 2010 year goal and the information technological environment is fast developing in Mongolia. By the tendency of fast moving development of information and technological change will make a road to be possible implementing the Home-Shopping in Mongolia. To meet the changeable tendency and countermeasures of Mongolian environment, e-Business policies are necessary. In this paper I like to point out why the Mongolian enterprises should have keen interest on e-Business and on the ground of the necessity on it. I like to suggest some models for Mongolia.

• Proceedings of the Optical Society of Korea Conference
• /
• 2001.02a
• /
• pp.4-5
• /
• 2001

Advent of lasers offering high intensity beam has opened the glass to the nonlinear optic (NLO). The high electric field associated with such laser beams can be so large that high order components of the glass polarization can be measured. Such development is of scientific and technological interests in particular in systems involving an intensity-dependent refractive index and/or ultra-fast response (＜10$\^$-12/s). From a scientific viewpoint the NLO response intensity must be understood as a function of the glass composition. On the other hand, large family of applications are presently under investigation in various fields of optical materials or systems e.g. laser glasses for fusion energy, soliton propagation for ultra-long distances, ultra-fast-switching, optical storage etc....(omitted)

• Publications of The Korean Astronomical Society
• /
• v.11 no.1
• /
• pp.91-107
• /
• 1996

We determine analytically the onset of thin-shell formation time of fast wind bubble with power-law energy injection $E_{in}=E_0t^s$, and power-law ambient density structure, ${\rho}_0(r)={\bar{\rho}}(r/{\bar{r}})^{-{\omega}}$. Thin-shell formation time, $t_{sf}$ can be estimated by minimizing the total time elapsed before the complete cooling of shocked gas. For uniform medium (${\omega}=0$) and constant energy injection (s = 1), the onset of shell formation is found to be at $t_{sf}=5.2{\times}10^3yr$, which agrees Quite well with the results of FCT 1D numerical calculation. We solve the line transfer problem with previous result derived by numerical calculation in order to calculate line profile of [OIII] (${\lambda}=5007{\AA}$) forbidden line. In general, radiative outer shell causes the formation of double peaked line profile. Each peak corresponds to approaching and receeding shells with large velocities. Our line profiles show good agreements with observation of expanding shell structure.

• Communications for Statistical Applications and Methods
• /
• v.27 no.2
• /
• pp.255-268
• /
• 2020

A mixture of multivariate canonical fundamental skew t-distribution (CFUST) has been of interest in various fields. In particular, interest in the unsupervised learning society is noteworthy. However, fitting the model via EM algorithm suffers from significant processing time. The main cause is due to the calculation of many multivariate t-cdfs (cumulative distribution functions) in E-step. In this article, we provide an approximate, but fast calculation method for the in univariate fashion, which is the product of successively conditional univariate t-cdfs with Taylor's first order approximation. By replacing all multivariate t-cdfs in E-step with the proposed approximate versions, we obtain the admissible results of fitting the model, where it gives 85% reduction time for the 5 dimensional skewness case of the Australian Institution Sport data set. For this approach, discussions about rough properties, advantages and limits are also presented.

• The Journal of Society for e-Business Studies
• /
• v.24 no.2
• /
• pp.217-228
• /
• 2019

In the 4th Industrial Revolution, the Internet of Things emerged and various services and convenience improved. As the frequency of use increases, security threats such as leakage of personal information coexist and the importance of security are increasing. In this paper, we analyze the security threats of the Internet of things and propose a model for enhancing security through user authentication using Fast IDentity Online (FIDO). As a result, we propose to implement strong user authentication by introducing second authentication through FIDO.

• ETRI Journal
• /
• v.29 no.2
• /
• pp.143-152
• /
• 2007

In this paper, we propose a time-varying modified minimum mean-squared error (MMSE) detector for the detection of higher data rate signals in a multirate asynchronous code-division multiple-access (CDMA) system which is signaled in a fast Rayleigh fading channel. The interference viewed by a higher data rate symbol will be periodic due to the presence of a lower data rate symbol which spans multiple higher data rate symbols. The detection is carried out on the basis of a modified MMSE criterion which incorporates differential detection and the ratio of channel coefficients in two consecutive observation intervals inherently compensating the fast variation of the channel due to fading. The numerical results obtained by the MMSE detector with time-varying detection show around 3 dB (M=2) and 6 dB (M=4) performance improvement at a BER of $10^{-3}$ in the AWGN channel, while introducing more computational complexity than the MMSE detector without time-varying detection. At a higher $E_b/N_0$, the proposed scheme can achieve a BER of approximately $10^{-3}$ in the presence of fast channel variation which is an improvement over other schemes.

• Nuclear Engineering and Technology
• /
• v.56 no.3
• /
• pp.900-906
• /
• 2024

The Passively-Cooled Molten Salt Fast Reactor (PMFR) is one of the advanced design concepts of the Molten Salt Fast Reactor (MSFR) which utilizes a natural circulation for the primary loop and aims to attain a long-life operation without any means of fuel reprocessing. For an extended operation period, it is necessary to have enough fissile material, i.e., high excess reactivity, at the onset of operation. Since the PMFR is based on a fast neutron spectrum, direct implementation of a burnable absorber concept for the control of excess reactivity would be ineffective. Therefore, a localized moderator concept that encircles the active core has been envisioned for the PMFR which enables the effective utilization of a burnable absorber to achieve low reactivity swing and long-life operation. The modified PMFR design that incorporates a moderator and burnable absorber is presented, where depletion calculation is performed to estimate the reactor lifetime and reactivity swing to assess the feasibility of the proposed design. All the presented neutronic analysis has been conducted based on the Monte Carlo Serpent2 code with ENDF/B-VII.1 library.

• Journal of Community Nutrition
• /
• v.7 no.1
• /
• pp.8-20
• /
• 2005

The study purpose was to examine which factors including health perceptions & behaviors, psychosocial factors, dietary intakes were different by stages of change to reduce fast food consumption among university students. Survey data(n = 341) were analyzed using X$^2$ test or analysis of variance. With respect to stages of change, $17\%$ were in the precontemplation ; $21.4\%$ for contemplation, $19.7\%$ for preparation, 11.7% for action, and $30.2\%$ for the maintenance stage. Frequency of fast food consumption (p < 0.001), health status, interest toward health, and exercising behavior (p < 0.05) differed significantly by stages of change. Demographics and nutrient intakes, however, had no association with stages of change. Those in precontemplation through preparation stages felt more strongly on the advantages such as taste, satiety, cleanness of restaurants (p < 0.001), and diverse menus (p < 0.05). Compared to maintainers or actors, pre-contemplators agreed less to the disadvantages of eating fast foods, including sanitary problems (p < 0.001), overeating, indigestion, decreased vegetable intakes (p < 0.01) and loss of freshness (p < 0.05). Influence of significant others (e.g., friends, siblings, parents) significantly differed by stages of change. Compared with maintainers, those in preaction stages felt less control over facilitators or situations for fast food consumption. These included 'others like fast foods', 'providing standard meals', 'when I don't have foods for meals'(p < 0.001), availability, advertisement, 'socially popular', 'when I feel hungry'(p < 0.01), and 'when I don't like to prepare meals' (p < 0.05). These results suggested that nutrition education be planned considering one's stages of change for fast food consumption. For those in preaction stages, it is desirable to use motivational strategies to increase benefits and remove barriers of change, and help to develop skills to deal with situations or factors for fast food consumption. The support from friends or families is also needed to move to further stages.

• The Research Journal of the Costume Culture
• /
• v.22 no.2
• /
• pp.225-239
• /
• 2014

This study examines how environmental consciousness and socially responsible clothing consumption attitude influence people's perceptions of the consequences of fast fashion. Data were collected through a questionnaire survey administered to females in their 20s to 40s, and a total of 430 surveys were used in the final analysis. The research results are as follows. First, environmental consciousness-which was conceptualized as interest in consumer effectiveness and the environment-had a positive influence on attitudes toward socially responsible clothing consumption attitude, i.e., clothing recycling and resource conservation. As the perception of consumer effectiveness was high, respondents had a tendency not to follow trends. Second, consumers with a high level of interest in the environment perceived the effect of fast fashion on the environment as serious, and they felt negatively toward personal use of fast fashion. Third, consumers with strong resource conservation behavior perceived the effect of fast fashion on the environment as serious, but those with positive attitudes toward secondhand clothing did not appear to have that perception. Finally, consumers who followed trends and those with weakly held attitudes about resource conservation felt positively toward personal use of fast fashion. The results of this research indicate that environmental consciousness is an important factor for socially responsible clothing consumption behavior. In addition, consumers with strong attitudes regarding resource conservation were more perceptive of the negative effect of fast fashion on the environment.