• Journal of the Korean Data and Information Science Society
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• v.7 no.2
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• pp.235-245
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• 1996

In this paper, we studied about several methods of testing hypothesis of correlation, specially Approximate method, Empirical method and Bootstrap method. The Approximate method is based on the Fisher's Z-transformation and the Empirical and Bootstrap methods approximate the distribution of the sample correlation coefficient by Monte Carlo simulation and Bootstrap technique, respectively. In order to compare how good these tests are, we computed powers under various alternatives. Consequently, we see that the Approximate test performs very well even if in small sample and all tests have almost the same power in large sample.

• BMB Reports
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• v.51 no.5
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• pp.230-235
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• 2018

Bone resorption by multinucleated osteoclasts is a multistep process involving adhesion to the bone matrix, migration to resorption sites, and formation of sealing zones and ruffled borders. Macrophage colony-stimulating factor (M-CSF) and osteopontin (OPN) have been shown to be involved in the bone resorption process by respective activation of integrin ${\alpha}v{\beta}3$ via "inside-out" and "outside-in" signaling. In this study, we investigated the link between signal modulators known to M-CSF- and OPN-induced osteoclast adhesion and spreading. M-CSF- and OPN-induced osteoclast adhesion was achieved via activation of stepwise signals, including integrin ${\alpha}v{\beta}3$, $PLC{\gamma}$, $PKC{\delta}$, and Rac1. Osteoclast spreading induced by M-CSF and OPN was shown to be controlled via sequential activation, consistent with the osteoclast adhesion processes. In contrast to osteoclast adhesion, osteoclast spreading induced by M-CSF and OPN was blocked via activation of $PLC{\gamma}/PKC{\alpha}/RhoA$ signaling. The combined results indicate that osteoclast adhesion and spreading are selectively regulated via $PLC{\gamma}/PKC{\alpha}-PKC{\delta}/RhoA-Rac1$ signaling.

• Bulletin of the Korean Chemical Society
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• v.32 no.12
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• pp.4304-4308
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• 2011

Kinetic studies of the reactions of O,O-dimethyl Z-S-aryl phosphorothioates with X-benzylamines have been carried out in dimethyl sulfoxide at $85.0^{\circ}C$. The Hammett (log $k_2$ vs ${\sigma}_X$) and Br$\ddot{o}$nsted [log $k_2$ vs $pK_a$(X)] plots for substituent X variations in the nucleophiles are discrete with a break region between 4-Me and H, while the Hammett plots (log $k_2$ vs ${\sigma}_Z$) for substituent Z variations in the leaving groups are linear. The sign of the cross-interaction constant (${\rho}_{XZ}$) is positive for both the strongly and weakly basic nucleophiles. Greater magnitude of ${\rho}_{XZ}$ (= 2.54) value is observed with the weakly basic nucleophiles compared to with the strongly basic nucleophiles (${\rho}_{XZ}$ = 0.17). The deuterium kinetic isotope effects ($k_H/k_D$) involving deuterated benzylamines [$XC_6H_4CH_2ND_2$] are primary normal ($k_H/k_D$ > 1). The proposed mechanism is a stepwise with a rate-limiting leaving group expulsion from the intermediate involving a frontside nucleophilic attack with a hydrogen bonded, four-center-type transition state for both the strongly and weakly basic nucleophiles.

• Journal of the Korean Operations Research and Management Science Society
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• v.22 no.1
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• pp.101-121
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• 1997

Consider a Jackson type closed queueing network in which each queue has a single exponential server. Assume that N customers are moving among .kappa. queues. We propose a candidata procedure which yields a lower bound of the network throughput which is sharper than those which are currently available : Let (.rho.$_{1}$, ... .rho.$_{\kappa}$) be the loading vector, let x be a real number with 0 .leq. x .leq. N, and let y(x) denote that y is a function of x and be the unique positive solution of the equation. .sum.$_{i = 1}$$^{\kappa}$y(x) .rho.$_{i}$ (N - y(x) x $p_{i}$ ) = 1 Whitt [17] has shown that y(N) is a lower bound for the throughput. In this paper, we present evidence that y(N -1) is also a lower bound. In dosing so, we are led to formulate a rather general conjecture on 'quot;Migrating Critical Points'quot; (MCP). The .MCP. conjecture asserts that zeros of successive derivatives of certain rational functions migrate at an accelerating rate. We provide a proof of MCP in the polynomial case and some other special cases, including that in which the rational function has exactly two real poles and fewer than three real zeros.tion has exactly two real poles and fewer than three real zeros.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.311-315
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• 2000

A numerical investigation is made of time-dependent buoyant convection in a square of a non-Boussinesq fluid. The density-temperature$({\rho}-T)$ relation is modeled by a quadratic function, with the maximum density ${\rho}_M$ at temperature $T_M$. The horizontal walls of the square are insulated, and a pulsating temperature $T_H=T_M+{\Delta}T'\;sin({\omega}{\tau})$ is imposed on the hot vertical sidewall. The temperature at the cold wall $T_c$ is constant. Extensive numerical solutions to the governing Navier-Stokes equations are portrayed. Resonance is identified by monitoring the amplitude of the mid-plane Nusselt number, $A(Nu^*)$. The primary resonance frequency is found by matching ${\omega}$ to the nondimensional basic mode $N_1$ of internal gravity oscillations. Due to the quadratic$({\rho}-T)$ relationship, the effective pulsation frequency for density, $2{\omega}$, is meaningful, which brings forth the secondary resonance frequency, i.e., $2{\omega}=N_1$

• Bulletin of the Korean Chemical Society
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• v.23 no.3
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• pp.381-384
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• 2002

Second-order-rate constants ($k_N$) have been measured spectrophotometrically for the reactions of 4-nitrophenyl 2-thiophenecarboxylate (1a) with a series of secondary alicyclic amines in H2O containing 20 mole % DMSO at 25.0 $^{\circ}C$ . The ester 1a is less reactive than 4-nitrophenyl 2-furoate (1b) but more reactive than 4-nitrophenyl benzoate (1c) except towards piperazinium ion. The Brønsted-type plots for the aminolyses of 1a, 1b and 1c are linear with a $\beta$nuc value of 0.92, 0.84 and 0.85, respectively, indicating that the replacement of the CH=CH group by a sulfur or an oxygen atom in the benzoyl moiety of 1c does not cause any mechanism change. The reaction of piperidine with a series of substituted phenyl 2-thiophenecarboxylates gives a linear Hammett plot with a large $\rho^-$ value ($\rho^-$ = 3.11) when $\sigma^- $ constants are used. The linear Brønsted and Hammett plots with large $\beta$nuc and $\rho^-$ values suggest that the aminolysis of 1a proceeds via rate-determining break-down of the addition intermediate to the products.

• Journal of Microbiology and Biotechnology
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• v.18 no.1
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• pp.171-175
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• 2008

Here, we report that Vibrio parahaemolyticus induces a rapid remodeling of macrophage actin and activates RhoB GTPase. Mutational analysis revealed that the effects depend on type III secretion system 1 regulated translocation of a V. parahaemolyticus effector protein, VP1686, into the macrophages. Remodeling of actin is shown to be necessary for increased bacterial uptake followed by initiation of apoptosis in macrophages. This provides evidence for functional association of the VP1686 in triggering an eat me-and-die signal to the host.

• Journal of Microbiology and Biotechnology
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• v.5 no.6
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• pp.335-340
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• 1995

Two types of Rhizoctonia solani esterases induced by cutin hydrolysate were partially purified by ammonium sulfate precipitation and gel filtration. The esterase I with hydrolyzing activity toward both ${\rho}-ni-trophenyl$ butyrate and ${\rho}-nitrophenyl$ palmitate and the esterase II with hydrolyzing activity toward only ${\rho}-ni-trophenyl$ butyrate were inhibited by ebelactone B, an esterase inhibitor produced by actinomycetes with $IC_{50}$ values of 0.01 and $0.09{\;}\mu\textrm{g}/l$, respectively. Spraying on rice seedling with ebelactone B at a concentration of $30{\;}\mu\textrm{g}/ml$ completely suppressed infection by R. solani. Ebelactone B could not protect the wounded rice seedling and did not show any inhibitory effect on the mycelial growth at a concentration of 1 mg/ml. These results indicate that ebelactone B, an esterase inhibitor protects rice plants from infection with R. solani by inhibition of penetration, not through fungitoxic or fungicidal effect.

• Journal of the Korean Ceramic Society
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• v.40 no.10
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• pp.1015-1020
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• 2003

The Corrosion behavior of the matrix of the $\rho$-alumina bonded alumina vibrated castable was, on the basis of Jabsen's theory, elucidated by use of the Kingery's reaction mechanism. Corrosion of the matrix during induction period was controlled by the molecular diffusion. The temperature dependence of activation process is well established by the Arrhenius plots. The difference of Ca concentration between slag and interface is 23.2%, which causes a driving force of the materials transfer. The extent of the corrosion of the matrix is more deeper than that of the sintered mullite, but the corrosion mechanism can be well employed as the reaction mechanism proposed by the Kingery. The life time of the castable may be well estimated by the corrosion mechanism of Kingery.

• Journal of Magnetics
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• v.16 no.2
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• pp.192-195
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• 2011

The phase transition of vortex matter from solid to liquid was studied in iron-based superconductors. Based on the traditional vortex glass theory, we have examined the magnetoresistivity data of iron-based superconductors using our extended thermal activation model: $\rho(B,T)=\rho((T-T_g(B))/(T_c(0)-T_g(B)))^{v(z-1)}$. We predict that the magnetic field-dependent area S + $S_0$ which integrates $\rho$ with T is proportional to $B^{\beta}$, where ${\beta}$ is the vortex glass transition exponent. From our calculation, the vortex glass transition exponent is 0.33, close to the exponent of area $S_0$ + S is 0.31 in $SmO_{0.9}F_{0.1}FeAs$; the exponent of area S is 0.63, which is close to the irreversibility line exponent 2/3. Both of the results show the validity of our model. In addition, our model is shown to be effective in describing irreversibility behavior in layered superconductors.