• Journal of Chest Surgery
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• v.30 no.8
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• pp.747-751
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• 1997

We developed a subcutaneously adjustable new pulmonary artery banding device which can be easily tightened or released in patients with unstable postoperative hemodynamics. The banding device consists of stainless spring which is enveloped with PTFE, nd polyvinyl catheter(5F). And the adjuster consists of another polyvinyl tube with forming cap. We mark transluscent polyvinyl tube 1mm each in length. 6 dogs weighing 15 to 25 kg underwent banding of descending thoracic aorta with the device. At postoperative 1 and 2 day, the device was effectively banded and released. Even 3 months later, we noted effective banding with some degree of vessel injury. The preliminary animal study suggests that this new device may be applicable in patient with excessive pulmonary blood flow.

• Structural Engineering and Mechanics
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• v.75 no.5
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• pp.621-631
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• 2020

A laboratory experiment is conducted is to investigate the behaviour of a low-mass-ratio and high aspect ratio flexible cylinder under vortex-induced vibration (VIV). A flexible cylinder with aspect ratio of 100 and mass ratio of 1.17 is towed horizontally to generate uniform flow profile. The range of Reynolds number is from 1380 to 13800. Vibration amplitude, in-line and cross-flow frequency response, amplitude trajectory, mean tension variation and hydrodynamic force coefficients are analyzed based on the measurement from strain gauges, load cell and CCD camera. Experimental results indicate that broad-banded lock-in region is found for the cylinder with a small Strouhal number. The frequency switches in the present study indicates the change of the VIV phenomenon. The hydrodynamic force responses provide more understanding on the VIV of a low mass ratio cylinder.

• Economic and Environmental Geology
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• v.31 no.5
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• pp.415-424
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• 1998

In order to investigate soil-gas $^{222}Rn$ concentrations, Kwanak Campus (Seoul National University), Boeun (Choong-buk) and Gapyung (Kyonggi) areas were selected and classified depending on their base rock types. Radon risk indices of these study areas decrease in the order of Gapyung>Kwanak Campus>Boeun areas, and in the order of rock type as banded gneiss>granite gneiss>granite>black slate-shale>mica schist>shale-lirnestone>phyllite-schist. Radon emanating trends with water content and grain size of soils were assessed by modified Morse 3 min. method. Radon emanation increases with the increase of water content in soils which is lower than 6~16 wt.%, and decreases in the range of higher than 6-16 wt. %. It shows that Rn emanation increases with the decrease of soil grain size. Radioactivity analysis of radionuclides of 238U series in some soil samples shows that radioactive disequilibrium state between $^{226}Ra$ and $^{238}U$ exists owing to different geochemical behavior of each radionuclide, and, it is necessary to carry out radioactive isotope geochemical approach for soil-gas $^{222}Rn$ study.

• Journal of the Korean Ceramic Society
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• v.33 no.1
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• pp.56-64
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• 1996

A large amount of papers about the cubic-to-tetragonal phase transition the ferroelectric domain structures of the BaTiO3 were already reported but there exist still some needs to observe the domain behaviors directly. In this study the domain structures of the tinned plates prepared from ta single crystal grown by the TSSG technique were observed using a polarizing microscope TE and X-ray topography. The spatial relation be-tween the orientation states of domains was investigated and the effects of external stresses and electric fields on the behaviors of ferroelectric and ferroelastic domains were studied. All the 90$^{\circ}$walls cut off in the crystal are the wedge shaped lamellar domains and all the straight boundaries in the observed domain patte군 can be interpreted as the head-to-tail 90$^{\circ}$walls. The irregular overlapped boundaries commonly observed by using a polarizing microscope and X-ray topography are complex combinations of well-known 90$^{\circ}$walls and are domain walls were predominant and were stabilized after surface polishing. In the paraelectric phase region the domain walls vanished but the residual surface strain patterns could be seen at the same positions of the stabilized 90$^{\circ}$a-a walls in the tetragonal phase region, These stabilized walls resulted from the surface strain had a memory effect in domain formation during the repeated phase transitions and could notr be affected by an external electtric field.

• Journal of Welding and Joining
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• v.12 no.1
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• pp.73-79
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• 1994

Low cycle fatigue test was performed by companion specimens method to compare the properties of cyclic strain for the weldments of controlled rolling steel CR60 and welding structural steel SM58Q. And the result does not showed any difference of low cycle fatigue life between weldments. Especially, the values of coefficient of cyclic plastic strain $C_{p}$ and exponent of cyclic plastic strain $K_{p}$ of heat affected zones of CR60 steel and SM58Q steel were same. And $C_{p}$ and $K_{p}$ of CR60 steel were equal to the values of weld it means a good combination between the base metal, the heat affected zone and the weld of CR60 steel.eel.eel.

• The Journal of the Korea Contents Association
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• v.7 no.3
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• pp.42-49
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• 2007

This paper implements RFID(radio-frequency identification)System to which the system was apply SS(Spread Spectrum) method. The system designed by using the algorithm for microprocessor with PLL of the receiver, PN spread, modulation and demodulation of the transceiver, and transistor amplifier for the output of stabilized BPSK (Binary Phase Shift Keying) signal. furthermore, it reduced the interference of the signal by designing the micro-strip narrow banded patch antenna, which is convenient for printing and producing, and decreased the volume of filter size in the system. It is also designed for the lower powered system with the possible application to UHF band of $860\sim930MHz$ for the international standard frequency band, which is the quota share of RFID distribution system.

• Korean Journal of Agricultural Science
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• v.39 no.4
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• pp.483-489
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• 2012

Preference of stink bugs to various leguminous seeds was evaluated by using VTS (Video Tracking System) in laboratory. Major soybean stink bugs such as bean bug, Riptortus pedestris (Fabricius), one-banded stink bug, Piezodorus hybneri (Gmelin), eastern green stink bug, Nezara antennata (Scott), and sole bug, Dolycoris baccarum (L.) were significantly most attracted to Cheongjakong, a soybean variety, baited fish-net trap, followed by soybean varieties Ilpumgeomjeongkong and Taekwangkong, a peanut variety Daekwangdangkong, a kidney bean variety Gangnangkong, and a adzuki bean variety Jungwonpat, respectively in a soybean field. VTS observation in laboratory showed that R. pedestris and D. baccarum had significantly higher frequency of visit on Cheongjakong, followed by Ilpumgeomjeongkong. However, P. hybneri, N. antennata and Halyomorpha halys (Stal) had significantly higher number of visits on Cheongjakong, Seonnogkong and Jinpumkong, followed by Ilpumgeomjeongkong. The sojourned time of stink bugs, however, was significantly longer on Cheongjakong regardless of species of the bugs. Accordingly, Cheongjakong was evaluated as the most preferred soybean seed by fish-net trap and VTS. Thus, VTS is found to be an effective means to evaluate the food preference of stink bugs.

• Korean Journal of Ichthyology
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• v.26 no.2
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• pp.143-146
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• 2014

A single serranid specimen of Epinephelus radiatus was collected by a hook for the commercial longline fisheries occurred near Marado, Jeju Island, Korea. The present specimen was characterized by five irregular dark brown bands passing downward and forward from upper edge of body, scales in longitudinal row 107, and pored lateral line scales 55. This species is easily distinguishable from the morphologically similar Korean serranid species of E. poecilonotus based on band patterns on body. That is, the former has five irregular oblique dark-edged brown bands, and the latter has several long horizontal bands on lateral body. We propose a new Korean name, "Ma-ra-bari," for Epinephelus radiatus.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.9 no.2
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• pp.57-62
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• 1997

Based on the facts that significant parts of the harbor response spectrum usually reside in the vicinity of the Helmholtz mode in the eastern part of Korea. economically feasible redemption measures of seiches for malfunctioned harbors already in service is proposed by extending the wisdom of perforated breakwaters and adjusting the width of entrance channel as a control tool. It turns out that as the entrance channel is getting narrower, the harbor system is getting slender due to the increase of added hydrodynamic length so that harbor response can be effectively diminished and separated from the incident wave spectrum where considerable amount of wave energy is located at the lower frequency range.

• Structural Engineering and Mechanics
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• v.55 no.5
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• pp.1055-1086
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• 2015

The dynamic response of two-dimensional unbounded domain on the rigid bedrock in the time domain is numerically obtained. It is realized by the modified scaled boundary finite element method (SBFEM) in which the original scaling center is replaced by a scaling line. The formulation bases on expanding dynamic stiffness by using the continued fraction approach. The solution converges rapidly over the whole time range along with the order of the continued fraction increases. In addition, the method is suitable for large scale systems. The numerical method is employed which is a combination of the time domain SBFEM for far field and the finite element method used for near field. By using the continued fraction solution and introducing auxiliary variables, the equation of motion of unbounded domain is built. Applying the spectral shifting technique, the virtual modes of motion equation are eliminated. Standard procedure in structural dynamic is directly applicable for time domain problem. Since the coefficient matrixes of equation are banded and symmetric, the equation can be solved efficiently by using the direct time domain integration method. Numerical examples demonstrate the increased robustness, accuracy and superiority of the proposed method. The suitability of proposed method for time domain simulations of complex systems is also demonstrated.