• Journal of Ocean Engineering and Technology
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• v.31 no.4
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• pp.266-273
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• 2017

In recent years, LNG bunkering terminals are needed to supply LNG as fuel to meet the emission requirements of the International Maritime Organization (IMO). A floating LNG bunkering terminal (FLBT) is one of the most cost-effective and environmentally friendly LNG bunkering systems for storing LNG and transferring it directly to an LNG fuel vessel. The FLBT maintains its position using mooring systems such as spread mooring and turret mooring. The loads on the vessel and mooring lines must be carefully determined to maintain their positions within the operable area. In this study, the wind loads acting in several side-by-side arrangements on the FLBT and LNG-BS were estimated using wind tunnel tests in the Force Technology, and the shielding effect due to the presence of ships upstream was evaluated. In addition, the empirical formulations proposed by Fujiwara et al. (2012) were used to estimate the wind force coefficients acting on the FLBT and those results were compared with experimental results.

• The Korean Journal of Ceramics
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• v.6 no.4
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• pp.380-384
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• 2000

Crystal structure of $Ba_5-5X$Y$_10/3$Nb$_10$O$_30$ was tried to determine by Rietveld analysis using powder X-ray diffraction data. This compound has tetragonal tungsten bronze (TTB) structure with general formula, (Al)$_2$(A2)$_4$(B1)$_2$(B2)$_8$(O1)$_8$(O2)$_8$(O3)$_4$(O4)$_2$(O5)$_4$(O6)$_4$. However, it was difficult to determine the distribution of Ba and Y in Al and A2 sites by the analysis only. Combination of Rietveld analysis and site potentials calculation as well as lattice energy calculations helped to determine the distribution. As the result, it was clarified that $Ba^2+$ cations occupy A2 (pentagonal tunnel site) and $Y^3+$ cations occupy Al (cubic site). The distribution of cations at each site coincides with the distribution estimated by the difference of ionic radii. This supports the formation condition of TTB which was proposed in our previous report. $Ba_5-5X$Y$_10X/3$Nb$_10$O$_30$ shows ferroelectric characteristics. In this compound, remanent polarization decreases slightly with the composition X. On the other hand, the result of crystal structure determination reveals that atomic positions along c-axis for A1, A2, B1 and B2 cations are also decreased with the composition X. This would suggest that the dependence of remanent polarization on composition X is derived by the dependence of atomic coordinates on composition X.

• Transactions of the Korean Society of Mechanical Engineers
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• v.13 no.4
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• pp.780-788
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• 1989

An experimental study has been performed to investigate the process from nonequilibrium state to equilibrium state in redeveloping turbulent boundary layer beyond separation-reattachment using pitot tube and hot-wire anemometer. The model sued in the experiment has the form of a backward facing step which is assembled by a two-dimensional 4:1 half elipse and a plate. Measurements are carried out up to a distance of about 50 step height downstream of the step, where the reattachment observed at about x/h=6.5. The profiles of the shape factor H the Clauser parameter G and the coefficient of friction $C^{f}$ exhibited the characteristics similar to those of the equilibrium turbulent boundary layer from x/h=25, and the profiles of the trubulent quantities did from x/h=35. However, the wake region of the boundary layer does not seem to recover the equilibrium turbulent boundary layer even at x/h=50. By considering the distributions of the intermittency factor it has been noted that the turbulence structure changes gradually from a mixing layer to a turbulent boundary layer along downstream direction after reattachment. This becomes clearer as we analyse the one-dimensional energy spectra and the dissipation energy spectra which are measured and caculated at various downstream positions after the backward facing step.p.

• Journal of Biomedical Engineering Research
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• v.15 no.3
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• pp.237-244
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• 1994

We investigated the qualitive and quantitative properties in EEG signal which responds to auditory stimulus with increaing the sound-cutting frequency from 2 Hz to 20 Hz by 2 Hz step units, by chaotic dynamics. To bigin with, general chaotic properties such as fractal mechanism, 1 If frequency spectrum and positive Lyapunov exponent are discussed in EEG signal. For evoked potential with given auditory stimulus, the route to chaos by bifurcation diagram and the changes in geometrical property of Poincare sections of 2-dimensional psedophase space is observed. For that containing spontaneous potential, seen as the random background signal, the chaotic attractors in 3-dimensional phase space are found containing the same infomation as the above mentioned evoked potential. Finally the chinges of Lyapunov exponent by various sound-cutting frequencies of stimulus and by the various spatial positions (occipital region) in a brain surface to be measured, are illustrated meaningfully.

• Microbiology and Biotechnology Letters
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• v.31 no.4
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• pp.311-321
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• 2003

Bacteria produce lipases, which can catalyze both the hydrolysis and the synthesis of long chain triglycerides. These reactions usually proceed with high regioselectivity and enantioselectivity, and, therefore, lipases have become very important biocatalysts used in organic chemistry. 3D lipase structures were solved from several bacterial lipases. They have an $\alpha/\beta$ hydrolase fold and a catalytic triad consisting of a nucleophilic serine, and an aspartate or glutamate residue that is hydrogen bonded to a histindine. Active sites are covered with $\alpha$-helical lid structure, of which movement is involved in the enzyme's activation at oil/water interface. Four substrate binding pockets were identified for triglycerides: an oxyanion hole and three pockets accommodating the fatty acids bound at positions sn-1, sn-2, and sn-3. These pockets determine the enantiopreference of a lipase. The understanding of structure-function relationships as well as the development of molecular evolution techniques will enable researchers to tailor new lipases for biotechnological applications.

• Archives of design research
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• v.15 no.3
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• pp.213-222
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• 2002

Graphic User Interface has been playing a great role in giving people easy access of computer. The research of implementing graphic image on the computer display and inventing mouse were the threshold of GUI's birth in 1960s, and those were succeeded to developing the first GUI based-computer at the Xerox research center in 1970s. An education theory for the children and the visual metaphor of real life environment were adapted to implement GUI. They were continuously studied and tested in the beginning of creating the GUI concept and design method. In 1980s, the GUI concept and design method were generally applied to all personal computer development. Apple and Microsoft have led the commercialization of their GUI based-05, and also got their own positions in the market as GUI standards in 1990s. The first research for the GUI based-computer implementation in Xerox has established very clear concept and design methods. This GUI standards are evolving Into more convenient and natural ways in various computing environment and developing technologies these days.

• Smart Structures and Systems
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• v.20 no.6
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• pp.769-780
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• 2017

Cable force monitoring is an essential and critical part of the safety evaluation of cable-supported bridges. A reasonable cable force monitoring scheme, particularly, sensor placement related to accurate safety assessment and budget cost-saving becomes a major concern of bridge administrative authorities. This paper presents optimal sensor placement for cable force monitoring by selecting representative sensor positions, which consider the spatial correlativeness existing in the cable group. The limited sensors would be utilized for maximizing useful information from the monitored bridges. The maximum information coefficient (MIC), mutual information (MI) based kernel density estimation, as well as Pearson coefficients, were all employed to detect potential spatial correlation in the cable group. Compared with the Pearson coefficient and MIC, the mutual information is more suitable for identifying the association existing in cable group and thus, is selected to describe the spatial relevance in this study. Then, the bond energy algorithm, which collects clusters based on the relationship of surrounding elements, is used for the optimal placement of cable sensors. Several optimal placement strategies are discussed with different correlation thresholds for the cable group of Nanjing No.3 Yangtze River Bridge, verifying the effectiveness of the proposed method.

• Journal of the Korean Institute of Gas
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• v.23 no.5
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• pp.35-43
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• 2019

The safety of industrial valves, which are the core parts of plant facilities, are managed by manpower and there are difficulties because of side area for inspection and limited accessibility due to the nature of facilities. The industrial valves used in plant facilities cause problems such as interrupted production; a loss of life due to leak or explosion of poisonous material and flammable gases, and difficulty in locating accident positions in the event of leakage or failure. Therefore, safety management and control systems based on IoT technology are needed. This study is about the development of risk factor prediction technique among the safety management of industrial valves through IoT- based wireless communication and the development of actuator control system. We have developed IoT-based industrial valve safety management techniques to prevent accidents caused by main risk factors by conducting an analysis of the structural characteristics of valves and an analysis of the causes of main risk factors through review of failure data and literature and an analysis of accident scenarios.

• Journal of the Korean Institute of Landscape Architecture
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• v.40 no.1
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• pp.12-22
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• 2012

In Seoul, skyscrapers are built in commercial zones known as residential-commercial complexes, which cause such environmental problems as urban heat islands(UHI) and air pollution. To investigate air temperature differences in areas near skyscrapers at Gangnam-gu, Seoul, South Korea, fixed air temperature observation and traverse observations were performed from March 16, 2008 to March 15, 2009. The annual mean air temperature at Tower Palace(TPL) was higher than that at Sookmyung Girls' High School(SMG) by $0.7^{\circ}C$, although the distance between the two observation positions is only 200m. The number of tropical nights at TPL was 13, while that at SMG was 5. The higher air temperature at TPL was due to a significantly lower sky view factor(SVF), which prevented long-wave radiation from emitting into the sky. The highest air temperature increases near TPL occurred on summer nights because of the high-electricity consumption value of $70.22Wh/m^2$ for the TPL block in August due to air conditioning for cooling. It is concluded that the warm air pocket centered on TPL.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.965-968
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• 2005

According to the rapid development of IT technologies, between different technologies and weakness of entry barriers, standardization for interoperability and intercompatibility is being recognized as a core strategy for preoccupation of global IT market and strengthening of national competitive power. Recently IPR(Intellectual property Rights) including patents is considered indispensably in international standardization. Also advanced countries strengthen their positions through preemption of global IT market by linking their IPR with international standardization. Therefore relationship between IPR and standardization is being changed to mutually complementary from mutually exclusive. In this paper, we will examine ITU-T's IPR policy and related discussion trends in ITU-T and try to find national policy for IPR related issues.