• Journal of the Korean Data and Information Science Society
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• v.19 no.4
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• pp.1391-1396
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• 2008

In this paper, we consider two components system which the lifetimes have Marshall and Olkin's bivariate exponential model with bivariate type I censored data. We propose a Bayesian independent test procedure for above model using fractional Bayes factor method by O'Hagan based on improper prior distributions. And we compute the fractional Bayes factor and the posterior probabilities for the hypotheses, respectively. Also we select a hypothesis which has the largest posterior probability. Finally a numerical example is given to illustrate our Bayesian testing procedure.

• Economic and Environmental Geology
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• v.30 no.2
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• pp.153-161
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• 1997

Diagrams of $^{87}Sr/^{86}Sr$ versus Ba/Nb and MgO/FeO are scattered, and $^{87}Sr/^{86}Sr$ variation with the increase of $SiO_2$ are scattered in Gwangju granitoid. Diagrams of $(^{87}Sr/^{86}Sr)$i versus $(^{143}Nd/^{144}Nd)$i and ${\varepsilon}Nd$ versus 1/Nd variation are also scattered in Gwangju granitoid. It shows that the source magma of Gwangju granitoid are derived from partial melting materials of heterogeneous upper crust. Very low ${\varepsilon}Nd$ values (-15.19~-19.49) and very high ${\varepsilon}Sr$ values (92.72~308.85) mean that the source magma of Gwangju granitoid is derived from sedimentary substance melting. According to $(^{87}Sr/^{86}Sr)$ 180Ma, and the plot of ${\varepsilon}Sr$ versus ${\varepsilon}Nd$, the Gwangju granitoid shows that the source magma is derived from upper crust materials. Nd model ages of Gwangju granitoid (1.82~2.42G.A.) are older than meta-sediments of Okcheon formation (1.15~1.60G.A.) and similar or close to Pre-Cambrian gneiss complex of Ryoungnam massif (2.17~2.47G.A.or 2.11~2.38G.A.).Therefore, the source magma of the Gwangju granitoid could be derived from the partial melting of Pre-Cambrian gneiss complex of Ryoungnam massif.

• Journal of the Korean Mathematical Society
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• v.45 no.6
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• pp.1753-1767
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• 2008

Consider the nonparametric regression model $Y_{ni}\;=\;g(x_{ni})+{\epsilon}_{ni}$ ($1\;{\leq}\;i\;{\leq}\;n$), where g($\cdot$) is an unknown regression function, $x_{ni}$ are known fixed design points, and the correlated errors {${\epsilon}_{ni}$, $1\;{\leq}\;i\;{\leq}\;n$} have the same distribution as {$V_i$, $1\;{\leq}\;i\;{\leq}\;n$}, here $V_t\;=\;{\sum}^{\infty}_{j=-{\infty}}\;{\psi}_je_{t-j}$ with ${\sum}^{\infty}_{j=-{\infty}}\;|{\psi}_j|$ < $\infty$ and {$e_t$} are negatively associated random variables. Under appropriate conditions, we derive a Berry-Esseen type bound for the estimator of g($\cdot$). As corollary, by choice of the weights, the Berry-Esseen type bound can attain O($n^{-1/4}({\log}\;n)^{3/4}$).

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.8
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• pp.779-788
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• 1992

The Input /output (I /0) subsystem is often the bottleneck in high performance computer system. Generally, system performance evaluation models were enhanced to include the effect of the I/0 system. In this paper, we modeled the terminal servers which are Indispensable devices In distribution of computer resources. We use M /M /1 Queueing model for find out the point of the system performance FIFO buffer sizes In the terminal server arc the Important fanctions of the system design and could be effected to the overall system functions. We have proposed the of optimal buffer sizes in the model of terminal server for increasing the system performance. We analizing the vatting time for terruanl server using Queueing model. and We find out the reference model result from simulation.

• Progress in Superconductivity and Cryogenics
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• v.17 no.1
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• pp.6-9
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• 2015

For many applications of $ReBa_2Cu_3O_{7-x}$ (ReBCO) tapes it is needed to know the anisotropic properties of the used conductor in a broad range of magnetic field. In this paper we present the results of transport measurements on the SuNAM tape (GdBaCuO) with the rotation of the sample in magnetic fields up to 5 T in liquid nitrogen. The critical current over the magnetic field orientation ($I_c({\theta})$) curves demonstrate the appearance of distinct second peak around c-axis in low fields. This peak almost vanishes in the fields over 3 T. The evolution of the ab-peak form is also presented: the peak consistently reduces its height with the magnetic field going up and in the high fields the shoulders rise, changing the type of the distribution. To describe experimental curves the vortex path model was applied to the angular distributions of the critical current in magnetic field. Good agreements of the experimental data with the analytical expressions were obtained that confirm the vortex path model approach.

• Journal of Korea Foresty Energy
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• v.20 no.1
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• pp.35-41
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• 2001

Lignin model compounds I-lV were pyrolyzed at 315$^{\circ}C$. The mixture compounds pyrolized were analyzed by GC-MS spectrometry. The results were summarized as follows : 1. From the pyrolysis of lignin model compound I and II, 0.45mo1 of guaiacol, 0.5mol of dimethoxyphenol(DMP), and 0.12 and 0.23mo1 of dimethoxyacetonphenone(DMAP) were produced respectively. 2. In the pyrolysis of lignin model compound III and IV, 0.26mol of guaiacol, 0.30mo1 of DMP, and 0.09 and 0.15mo1 of trimethoxyaretonphenone(TMAP) were produced respectively 3. Pyrolysis mechanism of lignin model compounds are dehydrated at first, and $\beta$-04 linkage cleavaged, and then guaiacol, DMP, DMAP and TMAP were produced. The above results show that lignin model compound I and II produce more aromatic compounds than lignin model compound III and IV. This is reason that veratryl unit structures may pyrolize easier than trimethoxyphenol unit structures. The closer research is proceeding.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10b
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• pp.1764-1769
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• 1991

Recently, dexterous mechanical hands have become of interest in the field of robotics. In this paper, a new symbolic C-Y notation is proposed for the kinematic modeling, and we solve the kinematics of a simplified model of POSTECH Hand 1, which is a 5 fingered, 20 degrees of freedom anthropomorphic hand. POSTECH Hand I is designed to have distinctive kinematic structure and the kinematic analysis of the hand is carried out using C-Y notation. To prove the feasibility of C-Y notation, D-H notation is also applied to the POSTECH Hand 1. In the inverse kinematic analysis, we neglect the fingertip geometry and assume the point contact with 3 degrees of freedom constraints. The configurations which optimize manipulability index[2] was obtained based on the simulation experiments on the SUN-4 graphic workstation using SUNPhigs graphic software.

• Journal of Ecology and Environment
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• v.35 no.2
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• pp.99-109
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• 2012

Litterfall dynamics in forests are assessed by estimating biomass production and decomposition. However, there have been few studies on how litter dynamics impact the health and management of ecosystems. Here, a new approach to measure and assess ecosystem function is presented based on conventional methods using littertraps, litterbags, and the mass on the forest floor. To assess the status of litter dynamics, the decay rate (k) was estimated from a litterbag experiment, and removal rates ($k_i$) were determined from mass balance on the forest floor at 21 sites on three mountains in South Korea. The $k_3$ (organic mass ratio of $O_i$ and $O_e+O_a$ + A horizons in November) values in an equilibrium state in South Korea were within the range of $k{\pm}0.174$ when considering the annual variation of litterfall production. This study also suggests that sampling sites for these types of studies should be in the middle, not at the ends, of steady slopes on the forest floor.

• Journal of Biomedical Engineering Research
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• v.2 no.1
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• pp.21-30
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• 1981

In this study, measuring eye movements with E.O.G. to targets beyond 20$^{\circ}$ from fixation point, results are as follows. (1) When the eyes turn toward targets of more than 20$^{\circ}$ eccentricity, the first saccadic eye movement falls short of the target. The presence of image of the target off the fovea(visual error signal) subsequent to such an undershoot elicits, after short interval, corrective saccadic eye movements(usually one) which place the image of the target on the fovea. (2) There are different programming modes at retina for eye movement to targets within and beyond 20$^{\circ}$ from the fixation point. (3) Saccadic system, preparing the direction and amplitude of eye movement completes the corrective saccadic eye movements. (4) Distribution of latency and intersaccadic interval(I.S.I.)are frequently multi modal, with a seperation between modes of 25[msec]. (5) There are two types of saccadic eye movements for the double-step targets. This fact suggests that the visual information is sampled stochastically. (6) The new model of saccadic system including the dissociation of visual functions dependent on retinal eccentricity is required.

• Journal of the Korean earth science society
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• v.42 no.2
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• pp.149-163
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• 2021

In this study, the changes in ozone (O3) concentrations due to the removal of power plant emissions were analyzed using a community multi-scale air quality (CMAQ) model. Two different CMAQ model simulations, one considering the emissions from the Hadong power plant and one without considering the emissions, were conducted to investigate the effect of the emissions on the changes in the O3 concentrations in the surrounding areas. Subsequently, the CMAQ simulations exhibited an increase in the O3 concentration (25.24%) despite a decrease in the NOx (-18.87%) and volatile organic carbon (VOC, -11.27%) concentrations, which are major O3 precursors. The changes in the NO and O3 concentrations due to the removal of power plant emissions presented a strong negative correlation (r= -0.72). This indicated that the increase in the O3 concentration was mainly attributed to the significantly decreased NO concentration, thus, mitigating the O3 titration reaction (NO+O3→NO2+O2). Additionally, due to the VOC-limited (i.e., NOx-saturated) conditions in the study region, NO affected the O3 concentration, indicating that the O3 concentrations in a particular region are not only proportional to the increase or decrease in emissions. Therefore, an in-depth understanding of the chemical O3 production and loss in a particular region is necessary to accurately evaluate the effect of emission control on the changes in the O3 concentration.