• The Journal of Information Systems
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• v.13 no.1
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• pp.97-119
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• 2004

Recently, many e-business companies started to charge fees to the use of information contents service. However, little is known about how users evaluate and determine to purchase information services. Past technology adoption research has focused primarily on the positive utility gains side, focusing on usefulness and ease of use. Purchase of e-service, however, involves not only the position utilities but also negative utilities. This research uses the service value model(SVM) and explains user's intention of purchasing a new information service. Based on the Perceived Value Framework, this research investigates the impacts of the service quality and the fee charge on the user's perceived service value and further on user's intention of adopting the e-service. One of the most important postulations of this research is that both service quality and the fee charge influence user's intention through affecting the user's perceived service value. This research presences a conceptual model of users' e-service evaluation process. The conceptual framework provides a basis for understanding how perceptions of quality and sacrifice influence value perceptions and purchase intentions. The results of an empirical research suggest that the both service quality and fee charge have influences on the perceived service value. However, they do not directly affect user's intention to purchase the e-service. They affect user's intention to purchase through affecting the perceived service value. In conclusion, this research provides a base to build on for other research studying use intention model of new e-service.

• Journal of ILASS-Korea
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• v.2 no.4
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• pp.29-35
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• 1997

Liquid film thickness is measured by $moir\acute{e}$ topography which monitored liquid surface. $Moir\acute{e}$ fringe measurement techniques share the inherent simplicity found in optical interferometric techniques have the advantage of use over a greater range of displacement. $Moir\acute{e}$ fringe are the geometric interference patterns observed when two dense line grating are superposed. Light transmitted through a fixed line grating is deviated by the liquid film surface, producing a distored image of the grating. The $moir\acute{e}$ fringe produced by projection of this optically distored grating onto a second stationary grating permit visualization of the liquid surface and measurement of the liquid film thickness. This study measured the small amplitude of liquid film thickness to the $moir\acute{e}$ fringe pattern produced when spherical metal was dropped glycerin put)1 And the measurement of liquid film thickness flowing down an inclined plate are required to calculate the liquid slope in a position.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.3
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• pp.259-265
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• 2015

It is clearly understood that e-navigation is beneficial to prevent collision and grounding of ships. The purpose of this study is to define and present a future ship operation system under the e-navigation environment in order to provide clear direction for the design of Korean e-navigation system. The future ship operation system consists of shipboard navigational system, shore supporting system and maritime communication system. To achieve the objectives of this study, the ship operation system was discussed separately into SOLAS ships and non-SOLAS ships in this study. In SOLAS ships, mariners become a system manager, choosing system presets, interpreting system output, and monitoring vessel response. In small ships and fishing vessels, mariners may enjoy their navigation by using the automatic tracking of ship's position on the portable electronic chart display. The improved bridge design, integrated and harmonized navigational system and single window reporting will reduce significantly the administrative and physical workload of mariners. Mariners can concentrate their attention more on navigational duty under the e-navigation environment. To build an effective Korean e-navigation system, the essential navigational functions and e-navigation services for small ships and fishing vessels must be identified and developed taking into account user needs.

• East Asian mathematical journal
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• v.34 no.5
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• pp.643-649
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• 2018

Let M be a connected n-dimensional submanifold of a Euclidean space $E^{n+k}$ equipped with the induced metric and ${\Delta}$ its Laplacian. If the position vector x of M is decomposed as a sum of three vectors $x=x_1+x_2+x_0$ where two vectors $x_1$ and $x_2$ are non-constant eigenvectors of the Laplacian, i.e., ${\Delta}x_i={\lambda}_ix_i$, i = 1, 2 (${\lambda}_i{\in}R$) and $x_0$ is a constant vector, then, M is called a 2-type submanifold. In this paper we proved that a connected 2-type hypersurface M in $E^{n+1}$ whose postion vector x satisfies ${\langle}{\Delta}x,x-x_0{\rangle}=c$ for a constant c, where ${\langle}$, ${\rangle}$ is the usual inner product in $E^{n+1}$, is of null 2-type and has constant mean curvature and scalar curvature.

• Journal of the Korean Vacuum Society
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• v.5 no.4
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• pp.278-283
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• 1996

We constructed a single path cylindrical mirror analyser(CMA) using field terminator methods. With computer simulation, the best fit voltage ratio and position of the field terminaor was determined with maintain log-scale equipotential line near both end of the CMA. Then we construct field terminator with voltage divider of metal-oxide resisters which reduces the fringe field effect. The resolving power of the CMA was better than $\Delta$E/E=0.4%.

• Bulletin of the Korean Mathematical Society
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• v.34 no.2
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• pp.155-171
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• 1997

Let $M^n$ be a connected subminifold of a Euclidean space $E^m$, equipped with the induced metric. Denoty by $\Delta$ the Laplacian operator of $M^n$ and by x the position vector. A well-known T. Takahashi's theorem [13] says that $\delta x = \lambda x$ for some constant $\lambda$ if and only if $M^n$ is either minimal subminifold of $E^m$ or minimal submanifold in a hypersphere of $E^m$. In [9], O. Garay studied the hypersurfaces $M^n$ in $E^{n+1}$ satisfying $\delta x = Dx$, where D is a diagonal matrix, and he classified such hypersurfaces. Garay's condition can be seen as a generalization of T.

• The Journal of Korean Medicine
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• v.37 no.1
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• pp.114-124
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• 2016

Objectives: The aim of this study is to find what effects both the posture of sitting and standing and the ratio of inhalation and exhalation (I/E) have on heart rate variability (HRV) Methods: We made two breathing sets with 4:6 or 6:4 ratios of I/E at 0.1 Hz of respiratory frequency and sitting or standing position. There was 20 minute-rest between sets. Each set include 5 minute-3 breathings as follows: 0.1Hz paced breath with sitting, usual breathing with standing and 0.1Hz paced breath with standing. Five minute-usual breathings with sitting as basal lines were exerted before and after these 3 breaths. Electrocardiogram-recording was exerted from 73 healthy participants (37 men and 36 women) who carried out two sets of breathings. Finally, HRV indices were analyzed of 62 participants (32 men and 30 women). Results: In 4:6 maintaining the same posture, SDNN were statistically increased, while mean heart rate(HR) were not changed. In 6:4, mean HR, SDNN were statistically increased. When changed from sitting to standing, in 4:6, SDNN were statistically decreased and mean HR was increased. However, in 6:4 during change of posture, SDNN were also statistically decreased and mean HR was statistically decreased. There was no statistical change of HF during 4:6 or 6:4 ratios of I/E moving from sitting to standing position. Conclusions: For increasing HRV, breathing in low respiratory rate with sitting was recommended regardless of ratio of I/E. In changing from sitting to standing, 4:6 may increase mean HR, and 6:4 may decrease mean HR.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2000.04a
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• pp.157-167
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• 2000

A thermostable chitosanase gene from the isolated strain, Bacillus sp. CK4, was cloned, and its complete DNA sequence was determined. The thermostable chitosanase gene was composed of an 822-bp open reading frame which encodes a protein of 242 amino acids and a signal peptide corresponding to a 30 kDa enzyme in size. The deduced amino acid sequence of the chitosanase from Bacillus sp. CK4 exhibits 76.6%, 15.3%, and 14.2% similarities to those from Bacillus subtilis, Bacillus ehemensis, and Bacillus circulans, respectively. C-terminal homology analysis shows that Bacillus sp. CK4 belongs to the Cluster III group with Bacillus subtilis. The size of the gene was similar to that of a mesophile, Bacillus subtilis showing a higher preference for codons ending in G or C. The functional importance of a conserved region in a novel chitosanase from Bacillus sp. CK4 was investigated. Each of the three carboxylic amino acid residues were changed to E50D/Q, E62D/Q, and D66N/E by site-directed mutagenesis. The D66N/E mutants enzymes had remarkably decreased kinetic parameters such as $V_{max}$ and k$\sub$cat/, indicating that the Asp-66 residue was essential for catalysis. The thermostable chitosanase contains three cysteine residues at position 49, 72, and 211. Titration of the Cys residues with DTNB showed that none of them were involved in disulfide bond. The C49S and C72S mutant enzymes were as stable to thermal inactivation and denaturating agents as the wild-type enzyme. However the half-life of the C211S mutant enzyme was less than 60 min at 80$^{\circ}C$, while that of the wild type enzyme was about 90 min. Moreover, the residual activity of C211S was substantially decreased by 8 M urea, and fully lost catalytic activity by 40% ethanol. These results show that the substitution of Cys with Ser at position 211 seems to affect the conformational stability of the chitosanase.

• Natural Product Sciences
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• v.16 no.1
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• pp.1-5
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• 2010

$\beta$-Glucuronidases (E.C. 3.2.1.31) from Escherichia coli, Helix pomatia, and bovine liver activity have been investigated on 7-O-glucuronides (baicalin, wogonoside, and luteolin-7-O-glucuronide) and 3-O-glucuronides (quercetin-3-O-glucuronide and kaempferol-3-O-glucuronide). Bovine liver enzyme was not active on any of these substrates. E. coli and H. pomatia enzymes were active on 7-O-glucuronides, however, 3-O-glucuronides were resistant to $\beta$-glucuronidase hydrolysis. These results suggest that glucuronic acid at 7-position is more susceptible to E. coli and H. pomatia $\beta$-glucuronidases than that at 3-position. In addition, the subtle difference of aglycone structure on 7-O-glucuronides affected the preference of enzyme. E. coli enzyme was favorable for the hydrolysis of baicalin, however, H. pomatia enzyme was found to be efficient for the hydrolysis of wogonoside. Both enzymes showed the similar hydrolytic activity towards luteolin-7-O-glucuronide. When the Scutellaria baicalensis crude extract was subjected to enzymatic hydrolysis, baicalin and wogonoside were successfully converted to their aglycone counterparts with H. pomatia at 50 mM sodium bicarbonate buffer pH 4.0. Accordingly, the enzymatic transformation of glycosides may be quite useful in preparing aglycones under mild conditions.

• Journal of Korean Critical Care Nursing
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• v.9 no.1
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• pp.66-76
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• 2016

Purpose: This study was conducted to examine the relationship between lateral position change and sternal complications after cardiac surgery through median sternotomy. Methods: This study was a retrospective descriptive case-control study, involving 241 patients who underwent cardiac surgery through median sternotomy. Data from October 2011 to September 2014 were collected. Results: Sternal complications (i.e. dehiscence, sternal instability, mediastinitis) developed in 33 patients (13.7%). Primary symptoms of complications were discharge and erythema, and the mean time difference from surgery to appearance of symptoms was 15 days (range, 1-138 days). The factors associated with sternal complications were cancer comorbidity (${\chi}^2=5.22$, p=.039), internal mammary artery procedure (${\chi}^2=4.16$, p=.041), and duration of extra-corporeal membrane oxygenation (p=.033). Position change was not related to incidence of sternal complications (${\chi}^2=0.14$, p=.704). Pressure ulcers appeared in 63 patients (26.1%). Mean time difference from surgery until occurrence of ulcers was 6.7 hours (range, 0-323.0 hours), but position change was started from 132.4 hours (range, 27.1-503.2 hours) after intensive care unit admission. Conclusions: These results provide baseline data to create a standard position change and activity protocol for patients after median sternotomy. Furthermore, the study could help clinical practitioners establish evidence-based nursing practices.