• Journal of Navigation and Port Research
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• v.27 no.1
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• pp.63-70
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• 2003

If semi-rigid connections are used for superstructures of very large floating structures (VLFS), the number of rigid connections can be reduced and more economical construction will be possible. In this study, considering service load and wave load in VLFS, the applicability of mixed use of rigid and semi-rigid connections have been studied using three types of connections for a four-bay eight-story frame. Three types of connections are used; top and seat-angle connections with double web-angle(TSD), extended end plate connections, steel tubular column with square external-diaphragm connections. ABAQUS(Finite element analysis program) is used for conducting second order elastic analysis.

• Food Science and Preservation
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• v.18 no.4
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• pp.429-435
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• 2011

The demand of packaged baby leaves has been increased for its convenient use as fresh-cut produce. This investigation was aimed to explore the effects of different sanitizers on the quality parameters of 'Tah Tasai' Chinese cabbage (Brassica campestris var. narinosa) baby leaves. Thirteen days old baby leaves were harvested and washed in tap water (TW), 100 ppm chlorine solution (Cl), 2 ppm ozonated water ($O_3$), 15 ppm chlorine dioxide solution ($ClO_2$) and washing with 0.2% citric acid solution followed by 50% ethanol spray (CA+Et). The samples were then packaged in 50 ${\mu}m$ polyethylene bags and stored at $5^{\circ}C$ for 10 days. Off-odor of packaged baby leaves was not detected during storage. There was no significant difference in color parameters among the treatments. Samples treated with $O_3$ showed substantially higher electrolyte leakage throughout the storage. This treatment also rendered a higher accumulation of $CO_2$ in the packages. Samples treated with Cl and CA+Et maintained good overall visual quality with higher scores compared to that of $O_3$ and $ClO_2$. Although Cl treatment showed lower number of total aerobic count at the beginning of storage, citric acid in combination with ethanol treatment was more effective until the end of storage. The combined treatment also showed comparatively lower coliform plate count. This result indicates that citric acid wash followed by ethanol spray could be an alternative to chlorine for environment friendly sanitization of baby leaves.

• Journal of the Society of Naval Architects of Korea
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• v.35 no.1
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• pp.88-97
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• 1998

Large aluminium extrusions can be used in rolling stocks and high speed vessels to reduce weight and labor cost. As sandwich plates with corrugated core have enough strength in transverse and longitudinal direction, welding lines to connect members are reduced and transverse members to strength longitudinal members are not required. However, for proper design of aluminium extrusion plates, understanding of structural behaviors of the exclusions are necessary. In this paper, at first, detailed finite element analysis is carried out to understand structural behavior. And then, simple theoretical formulas for design purpose are proposed using the orthotropic plate theory. Shear stresses resulting from end twisting which is characteristics of deep aluminium extrusion plates can also be calculated by the simple theoretical formula. Comparison with the results by detailed finite element analysis shows good accuracy of the proposed simple formulas. The simple formulas can be useful in repetitive analysis in the initial design stage.

• Korean Journal of Cleft Lip And Palate
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• v.3 no.2
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• pp.41-50
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• 2000

The alar base on the cleft side in unilateral complete cleft lip, alveolus and palate is markedly displaced laterally, caudally and dorsally, By incising the pyriform margin from the cleft margin of the alveolar process, including mucosa of the anterior part of the inferior turbinate, to the upper end of the postnasal vestibular fold, the alar base is released from the maxilla, A physiological correction of nasal deformity can be accomplished by careful reconstruction of nasolabial muscle integrity, functional repair of the orbicular muscle, raising and rotating the displaced alar cartilage, and finally by lining the lateral nasal vestibule, The inferior maxillary head of the nasal muscle complex is identified as the deeper muscle just below the web of the nostril, The muscle is repositioned inframedially, so that it is sutured to the periosteum that overlies the facial aspect of the premaxilla in the region of the developing lateral incisor tooth, And then, the deep superior part of the orbicular muscle is sutured to the periosteum and the fibrous tissue at the base of the septum, just in front of the anterior nasal spine, The nasal floor is surgically created by insertions of the nasal muscle complex in deep plane and of the orbicular muscle in superficial one, The upper part of the lateral nasal vestibular defect is sutured by shifting the alar flap cephalically, The middle and lower parts of this defect are closed by use of cleft margin flaps of the philtral and lateral segments, respectively, Authors stress the importance of nasal floor reconstruction at primary surgery and report the technique and postoperative results.

• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.6
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• pp.75-80
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• 2013

In this study, a forced ignition method with a plasma jet torch is studied in Mach 2 laboratory scaled wind-tunnel. The hyper-mixer is used as a mixer. For two normal injection cases, the one is collided against a wedge plate of the hyper-mixer and the other is directly injected into the cold main flow. For the first case, the hyper-mixer disperses the injected fuel, leading to the mixing enhancement. Furthermore, the fuel-air mixture is provided into the plasma hot gas, which enhances the combustion performance. However, the direct injection into the main flow method spends amount of fuel without ignition in the cold supersonic flow. In the end, for the forced combustion, it is important to supply the fuel-air mixture into the heat source.

• Transactions of the Korean hydrogen and new energy society
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• v.23 no.5
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• pp.468-475
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• 2012

A proper stacking force and assembly are important to the performance of fuel cell. Improper assembly pressure may lead to leakage of fuels and high interfacial contact resistance, excessive assembly pressure may result in damage to the gas diffusion layer and other components. The pressure distribution of gas diffusion layer is important to make interfacial contact resistance less for stack performance. To analyze the influence of design parameter factors for pressure distribution, and to optimize stack design, DOE (Design of Experiment) was used for polymer electrolyte membrane fuel cell stack pressure test. As commonly known, the higher clamping force improves the fuel cell stack performance. However, non-uniformity of stress distribution is also increased. It shows that optimization between clamping force and stress distribution is needed for well designed structure of fuel cell stack. In this study, stack design optimization method is suggested by using FEM (Finite Element Methode) and DOE for light-weighted fuel cell stack.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.1
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• pp.1-11
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• 2016

The information about the deformations of high-aspect-ratio wings is needed for the real-time monitoring of structural responses. Wing deformation in flight can be predicted by using relationship between the curvatures and the strains on the wing skin. It is also necessary to consider geometric nonlinearity when the large deformation of wing is occurred. The strain distribution on fixed-end is complex in the chordwise direction because of the geometric shape of fixed-wings on fuselages. Hence, the wing displacement can be diversely predicted by the location of the strain sensing lines in the chordwise direction. We conducted a study about prediction method of displacements regardless of the chordwise strain sensing locations. To correct spanwise strains, the ratio of spanwise strain to chordwise strain, Poisson's ratio, and the ratio of the plate strain to the beam strain were used. The predicted displacements using the strain correction were consistent with those calculated by the FEA and verified through the bending testing.

• Journal of the Korean Institute of Gas
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• v.11 no.2 s.35
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• pp.55-59
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• 2007

This paper presents the strength safety of a LPG cylinder, which is fabricated by a steel sheet forming and a welding technology. The strength safety of a cylinder is guaranteed by analyzing a stress distribution of a LPG cylinder structure using a finite element method. The FEM computed results indicate that the hydraulic test gas pressure of $31kg/cm^2$ generates a concentrated local stress near the upper round end plate, which exceeds the yield strength of a LPG cylinder. Thus, the current hydraulic test pressure may be rechecked and revised because this pressure increases the fatigue failure and decreases the lift of the pressure vessel. The normal operation and sealing gas pressures such as $9kg/cm^2\;and\;18.6kg/cm^2$ are relatively safe for a steel LPG cylinder.

• Conservation Science in Museum
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• v.14
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• pp.69-79
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• 2013

The area of conservation treatment of the bronze helmet of the ancient Greece, treasure No. 904, which Sohn Keechung (1912 to 2002) received as an extra prize for his winning the marathon in the 1936 Berlin Olympics deteriorated and as a result crack and discoloration occurred. Its nose guard hung downward due to the crack of the bonded area of upper end. Therefore, conservation treatment of the helmet was conducted again. The nose guard was separated from the body. Stabilization and consolidation treatment of them was made and then they were joined again. The cracked and missing areas were reinforced with woven glass fibers, and the nose guard was reinforced with woven glass fibers and Ti plate after the bonding. The joined area of the nose guard was carved with the same pattern as that of the surrounding area and its color was adjusted to be the same as well.

• Journal of Biomedical Engineering Research
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• v.17 no.4
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• pp.449-458
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• 1996

Most of the conventional electrocardiowaphs foil to detect signals other than P-QRS-T due to the limited SNR and bandwidth. High-resolution electrocardiography(HRECG) provides better SNR and wider bandwidth for the detection of micro-potentials with higher frequency components such as vontricular late potentials(LP). We have developed a HRECG using uncorrected XYZ lead for the detection of LPs. The overall gain of the amplifier is 4000 and the bandwidth is 0.5-300Hz without using 60Hz notch filter. Three 16-bit A/D converters sample X, Y, and Z signals simultaneously with a sampling frequency of 2000Hz. Sampled data are transmitted to a PC via a DMA-controlled, optically-coupled serial communication channel. In order to further reduce the noise, we implemented a signal averaging algorithm that averaged many instances of aligned beats. The beat alignment was carried out through the use of a template matching technique that finds a location maximizing cross-correlation with a given beat tem- plate. Beat alignment error was reduced to $\pm$0.25ms. FIR high-pass filter with cut-off frequency of 40Hz was applied to remove the low frequency components of the averaged X, Y, and Z signals. QRS onset and end point were determined from the vector magnitude of the sigrlaIL and some parameters needed to detect the existence of LP were estimated. The entire system was designed for the easy application of the future research topics including the optimal lead system, filter design, new parameter extraction, etc. In the developed HRECG, without signal averaging, the noise level was less than 5$\mu$V$_rms RTI$. With signal averaging of at least 100 beats, the noise level was reduced to 0.5$\mu$V$_rms RTI$, which is low enough to detect LPs. The developed HRECG will provide a new advanced functionality to interpretive ECG analyzers.