• Asian Pacific Journal of Cancer Prevention
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• v.17 no.8
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• pp.3855-3859
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• 2016

Colorectal cancer (CRC) is reproted to be the third most common cancer worldwide and the fourth most common cause of cancer related deaths. CRC is considered to be a multifactorial disease whose risk varies due to the complex interaction between individual genetic basis and disposure to multiple endogenous factors. Glutathione S-transferases are pro-carcinogenic in CRC and are required for the conjugation between chemotherapeutics and broad spectrum xenobiotics. One hundred and eleven patients with CRC and 128 control subjects without any cancer history were enrolled in this study. Multiplex PCR was applied to determine polymorphisms for the GSTT1 and M1 genes, and PCR-RFLP was applied for the GSTP1 (Ile105Val) gene polymorphism. Values p<0.05 were defined as statistically significant. We detected a significant high correlation between predisposition for CRC and presence of the Ile/Ile genotype of the GSTP1 (IIe105Val) gene polymorphism, but we did not find a significant relationship between predisposition for CRC and GSTT1 and M1 deletion polymorphisms. In addition, we did not determine a relationship between GSTT1, M1 and P1 gene polymorphisms and any clinicopathological features of CRC. GSTT1 null/GSTM1 positive and GSTT1 null/GSTM1 positive/GSTP1 Ile/Ile genotypes were significantly higher in the patient group. Our results revealed that there is no relationship among CRC, its clinicopathologic features, and GSTT1 M1 gene polymorphisms. However, there was a significant correlation between CRC and the GSTP1 Ile/Ile genotype. Further studies with larger patient groups are required to delineate the relationships between GST gene polymorphisms and the clinicopathologic features of CRC in Turkey.

• Ocean Science Journal
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• v.43 no.1
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• pp.17-24
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• 2008

Over a period of 5 days between August 12 and 17, 2005, we performed a gas exchange experiment using the dual tracer method in a tidal coastal ocean located off the southern coast of Korea. The gas exchange rate was determined from temporal changes in the ratio of $^3He$ to $SF_6$ measured daily in the surface mixed layer. The measured gas exchange rate($k_{CO_2}$), normalized to a Schmidt number of 600 for $CO_2$ in fresh water at $20^{\circ}C$, was approximately $5.0\;cm\;h^{-1}$ at a mean wind speed of $3.9\;ms^{-1}$ during the study period. This value is significantly less than those obtained from floating chamber-based experiments performed previously in estuarine environments, but is similar in magnitude to values obtained using the dual tracer method in river and tidal coastal waters and values predicted on the basis of the relationship between the gas exchange rate and wind speed (Wanninkhof 1992), which is generally applicable to the open ocean. Our result is also consistent with the relationship of Raymond and Cole (2001), which was derived from experiments carried out in estuarine environments using $^{222}Rn$ and chlorofluorocarbons along with measurements undertaken in the Hudson River, Canada, using $SF_6$ and $^3He$. Our results indicate that tidal action in a microtidal region did not discernibly enhance the measured $k_{CO_2}$ value.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.967-973
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• 2004

Electro-pneumatic servo valve is an electro-mechanical device which converts electric signals into a proper pneumatic flow rate or pressure. In order to improve the overall performance of pneumatic servo systems, electro-pneumatic servo valves are required, which have fast dynamic characteristics, no air leakage at a null point, and can be fabricated at a low-cost. The first objective of this research is to design and to fabricate a new electro-pneumatic servo valve which satisfies the above-mentioned requirements. In order to design the mechanism of the servo valve optimally, the flow inside the valve depending upon the position of spool was analyzed variously, and on the basis of such analysis results, the valve mechanism, which was formed by combination of the spool and the sleeve, was designed and manufactured. And a tester for conducting an overall performance test was designed and manufactured, and as a result of conducting the flow rate test, the pressure test and the frequency test on the developed pneumatic servo valve.

• 연구논문집
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• s.34
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• pp.69-77
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• 2004

Electro-pneumatic servo valve is an electro-mechanical device which converts electric signals into a proper pneumatic flow rate or pressure. In order to improve the overall performance of pneumatic servo systems, electro-pneumatic servo valves are required, which have fast dynamic characteristics, no air leakage at a null point, and can be fabricated at a low-cost. The objective of this research is to design and to fabricate a new electro-pneumatic servo valve which satisfies the above-mentioned requirements. In order to design the mechanism of the servo valve optimally, the flow inside the valve depending upon the position of spool was analyzed variously, and on the basis of such analysis results, the valve mechanism, which was formed by combination of the spool and the sleeve, was designed and manufactured. Further, the performance of pneumatic servo valve has been verified through an overall performance test on the developed product.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10b
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• pp.1150-1155
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• 1990

This paper proposes an optimal redundancy resolution of a kinematically redundant manipulator while considering homotopy classes. The necessary condition derived by minimizing an integral cost criterion results in a second-order differential equation. Also boundary conditions as well as the necessary condition are required to uniquely specify the solution. In the case of a cyclic task, we reformulate the periodic boundary value problem as a two point boundary value problem to find an initial joint velocity as many dimensions as the degrees of redundancy for given initial configuration. Initial conditions which provide desirable solutions are obtained by using the basis of the null projection operator. Finally, we show that the method can be used as a topological lifting method of nonhomotopic extremal solutions and also show the optimal solution with considering the manipulator dynamics.

• Communications for Statistical Applications and Methods
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• v.9 no.2
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• pp.389-399
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• 2002

In order to examine whether the difference between two point estimates of population proportions is statistically significant, data analysts use two techniques. The first is to explore the overlap between two associated confidence intervals. Second method is to test the significance which is introduced at most statistical textbooks under the common assumptions of consistency, asymptotic normality, and asymptotic independence of the estimates. Under the null hypothesis which is two population proportions are equal, the pooled estimator of population proportion is preferred as a point estimator since two independent random samples are considered to be collected from one population. Hence as an alternative method, we could obtain another confidence interval of the difference of the population proportions with using the pooled estimate. We conclude that, among three methods, the overlapped method is under-estimated, and the difference of the population proportions method is over-estimated on the basis of the proposed method.

• Journal of Korean Physical Therapy Science
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• v.10 no.1
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• pp.206-211
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• 2003

The purpose of this study is the effect of massage therapy on the human autonomic nerve system by heart rate variability spectral analysis. This study were to effect autonomic nerve system before and after massage therapy in 12 health peoples. The effect of massage therapy were assessments through Heart Rate Variability (HRV; SA-2000E, Medicare, Korea) before and after the massage therapy by same massage therapist. Statistical techniques for data analysis were applied paired t-test. The 0.05 level of significance was used as the critical level for rejection of the null hypotheses for the study. On the basis of the results analyzed in this study, conclusions were drawn as follows; Rest Heart Rate was significantly decreased before and after massage therapy, but other variable were no statistical significances. These results suggest that massage therapy maybe be effective in reducing heart rate and activity in valgal tone.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.8
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• pp.727-732
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• 2008

In this work, the etch characteristics of $VO_2$ thin films were investigated using inductively coupled plasma (ICP) of $Cl_2/Ar$ gas mixtures. To analyze the plasma characteristics, a quadrupole mass spectrometer (QMS), an optical emission spectroscopy (OES), and a Langmuir probe measuring system were used. The surface reaction of the $VO_2$ thin films was investigated using X-ray photoelectron spectroscopy (XPS). It was found that an increase in Ar fraction in the $Cl_2/Ar$ plasma at fixed gas pressure, input power, and bias power resulted in increasing $VO_2$ etch rate which reached a maximum value of 87.6 nm/min at 70-75 % Ar. It was confirmed that the etch rate of the $VO_2$ films was mainly controlled by the ion flux. On the basis of measuring results, we will discuss possible etching mechanism of $VO_2$ film in the $Cl_2/Ar$ plasma.

• Journal of Microbiology and Biotechnology
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• v.18 no.12
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• pp.1884-1889
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• 2008

The ${\beta}$-lactamase inhibitory protein, BLIP-II, found in the culture supernatant of Streptomyces exfoliatus SMF19, shows no discernible sequence identity with other ${\beta}$-lactamase inhibitory proteins identified in Streptomyces spp. A null mutant of the gene encoding BLIP-II (bliB::$hyg^r$) showed a bald appearance on solid media. Although BLIP-II was initially isolated from the supernatant of submerged cultures, sites of BLIP-II accumulation were seen in the cell envelope. Mutation of bliB was also associated with changes in the formation of septa and condensation of the chromosomal DNA associated with sporulation. The bliB mutant exhibited infrequent septa, showing dispersed chromosomal DNA throughout the mycelium, whereas the condensed chromosomes of the wild-type were separated by regularly spaced septa giving the appearance of a string of beads. Therefore, on the basis of these results, it is suggested that BLIP-II is a regulator of morphological differentiation in S. exfoliatus SMF19.

• Structural Engineering and Mechanics
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• v.54 no.6
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• pp.1153-1174
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• 2015

Deployable structures have gained more and more applications in space and civil structures, while it takes a large amount of computational resources to analyze this kind of multibody systems using common analysis methods. This paper presents a new approach for dynamic analysis of multibody systems consisting of both rigid bars and arbitrarily shaped rigid bodies. The bars and rigid bodies are connected through their nodes by ideal pin joints, which are usually fundamental components of deployable structures. Utilizing the Moore-Penrose generalized inverse matrix, equations of motion and constraint equations of the bars and rigid bodies are formulated with nodal Cartesian coordinates as unknowns. Based on the constraint equations, the nodal displacements are expressed as linear combination of the independent modes of the rigid body displacements, i.e., the null space orthogonal basis of the constraint matrix. The proposed method has less unknowns and a simple formulation compared with common multibody dynamic methods. An analysis program for the proposed method is developed, and its validity and efficiency are investigated by analyses of several representative numerical examples, where good accuracy and efficiency are demonstrated through comparison with commercial software package ADAMS.