• Journal of the Korean Magnetic Resonance Society
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• v.5 no.2
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• pp.110-117
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• 2001

$^{19}$ F imaging of mice was carried out. For $^{19}$ F imaging, 5-flouro-uracil (5-FU) was injected into a mouse and in vivo detection of the catabolism of 5-FU to a-fluoro-P-alanine (FBAL) was carried out. The chemical shift selective (CHESS) imaging technique was employed. The 19F spectra and images give temporal and spatial information of the metabolism for 5-FU in mice.

• Korea-Australia Rheology Journal
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• v.11 no.4
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• pp.279-285
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• 1999

Draw resonance is both an important and interesting instability encountered in various extensional-deformation-dominated polymer processing operations. It is important because of its paramount relevance to the productivity and quality issue in the related industry: and it is interesting because of as yet unanswered questions as to what its cause and origin are in terms of physics involved. Specifically, a short chronological account of the draw resonance research is presented in this paper bringing several previous results together and focusing on the derivation of a new criterion for draw resonance based on the interaction of the traveling times of some kinematic waves propagating along the spinline from the die exit to the take-up position. The new explanation of draw resonance put forward here based on the physics of the system is seen to have wide implications on both theoretical and practical aspects of draw resonance instability. The importance of the role played by spinline tension in determining draw resonance is an example of the former whereas interpretation of the mechanism of the draw resonance eliminator is an example of the latter. Finally, an approximate yet a very fast and convenient method for determining draw resonance is also derived based on the above findings and found to agree well with the exact stability results.

• Progress in Superconductivity and Cryogenics
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• v.17 no.1
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• pp.36-39
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• 2015

Many studies are being conducted to implement wireless charging, for example, for cellular phones or electronic tooth brushes, via wireless power transmission technique. However, the magnetic induction method had a very short transmission distance. To solve this problem, the team of Professor Marin Soljacic proposed a magnetic resonance system that used two resonance coils with the same resonance frequency. It had an approximately 40% efficiency at a 2m distance. The system improved the low efficiency and short distance problems of the existing systems. So it could also widen the application range of wireless power transmission. Many studies on the subject are underway. In this paper, the superconductor coil was used to improve the efficiency of magnetic resonance wireless power transmission. The resonance wireless power transmission system had a source coil, a load coil, and resonance coils (a transmitter and a receiver). The efficiency and distance depended on the characteristics of the transmitter and receiver coils that had the same resonance frequency. Therefore, two resonance coils were fabricated by superconductors. The current density of the superconductor was higher than that of the normal conductor coil. Accordingly, it had a high quality-factor and improved efficiency.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.11a
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• pp.150-155
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• 2000

This paper presents phenomena of vibration and noise due to acoustic resonance in tube bank of a power plant. Acoustic resonance is may arise when the vortex shedding frequency coincides with the acoustic natural frequency. At the resonance, the value of vibration in this system was 595 ${\mu}m$, p-p and the sound pressure level was maximum 103 dBA. And the resonance frequency was found to be 35 Hz. When the difference of vortex shedding frequency and acoustic natural frequency is within ${\pm}20%$, acoustic resonance is possible. In this system, the difference of these frequencies was 1.8%. We can evaluate the possibility of acoustic resonance by using damping parameter. We did eliminate acoustic resonance by installing baffle in tube bank. After installing baffle, the level of vibration and noise was reduced dramatically.

• The Journal of the Acoustical Society of Korea
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• v.30 no.4
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• pp.223-230
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• 2011

Korean bell is hung with some air gap between the bell bottom and the ground. In addition, it has a peculiar acoustic element, so called resonance cavity below the bell. A proper design of the air gap and cavity size dramatically amplifies the bell sound by resonance effect. Bell interior cavity, air gap and resonance cavity consist of an acoustic cavity system. When the acoustic cavity frequency coincides with the natural frequency of the bell body, the frequency component is significantly amplified. On the Sacred Bell of the Great King Seongdeok, this study proposes a resonance condition of the cavity system considering air gap effect for the first time. With the exact dimension of the bell, boundary element analysis is performed using SYSNOISE. Finally, this study reveals how the temperature in season influences the resonance condition and proposes a concept of variable type resonance cavity. By using the variable type resonance cavity, the cavity size is controlled on site and exact resonance is available regardless of temperature difference in season.

• Progress in Superconductivity and Cryogenics
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• v.20 no.1
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• pp.23-27
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• 2018

As the wireless power transfer (WPT) technology based on strongly resonance coupled method realizes large power charging without any wires through the air, there are advantages compared with the wired counterparts, such as convenient, safety and fearless transmission of power. From this reason, the WPT systems have started to be applied to the wireless charging for various power applications such as train, underwater ship, electric vehicle. This study aims for the effect and characteristics of different inserted resonance coil between Tx and Rx coils for charging system of superconducting magnetic levitation (MAGLEV) train. The transfer efficiency and effect are evaluated with helix type, rectangular type copper resonance coil, and HTS resonance coil under bulb and HTS magnet load, respectively. The input power is adapted with radio frequency (RF) power of 370 kHz below 500 W.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.04a
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• pp.698-702
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• 2013

This paper considers the vertical pumps resonance and soundness. Normally large vertical pump's rotating speed is low, so the low natural mode can make a resonance on the motor and motor stand assembly. The pump resonance makes a very high vibration and trouble on the pump systems. Thus to avoid pump resonance when the pump is on the resonance region, we give the added mass method and evaluate the structure soundness by computer simulation and test on the site. Furthermore we evaluate the modal sensitivity and expect running conditions by the using ISO10814.

• Journal of the Korean Magnetic Resonance Society
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• v.7 no.1
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• pp.46-54
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• 2003

We synthesized a contrast agent for MRI that is capable of binding to the ABP-1 receptor and enhancing the contrast of the targeted cells. We used a lysine dendrimer (G=3)DTPA[Gd] as the contrast agent and synthesized a biotinylated polyclonal antibody for ABP-1 as the first antibody. Lysine dendrimers were prepared using the solid phase peptide synthesis method.$^3$ Amino-terminated lysine dendrimers were then coupled to DTPA using the anhydride method. Gd was complexed with the DTPA-lysine dendrimer in an acidic solution of 3 eq GdCl$_3$ to one of DTPA. The lysine dendrimer-DTPA[Gd] and avidin were conjugated in MES solution, pH 6.0, using EDC as the coupling reagent. The biotin-avidin system was used to link the polyclonal antibody and contrast agent. K562 cells were used for imaging.

• Aerospace Engineering and Technology
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• v.7 no.1
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• pp.151-160
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• 2008

In this paper, the analysis results of synthetic resonance characteristics are described for the electrohydraulic thrust vector control actuation system. The synthetic resonance is induced by integration of position servo actuation system on the flexible launch vehicle mounting structure. The new resonance mode is synthesized due to composition of hydraulic resonance for electrohydraulic position servo system with inertia load condition and structural resonance for flexible mounting structure. This synthetic resonance can make stability of control system worse by feedback and amplification of control system. The exact nonlinear analysis model of this phenomenon is developed to predict and design a control algorithm for improvement characteristics. The DPF (Dynamic Pressure Feedback) control algorithm has been designed and has excellent resonance suppression capability.

• Journal of the Korean Vacuum Society
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• v.12 no.S1
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• pp.116-119
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• 2003

$Ni_2$MnGa films, deposited on mica and glass substrates, were studied by ferromagnetic resonance (FMR) technology. The temperature-dependent resonance field was measured and a martensitic phase transformation (MT) was found between 310 and 340 K, exhibiting an abnormality on the curve. The easy axis is found to be in the film plane. The line width increases as a whole with decreasing temperature, which is discussed in terms of the motional narrowing mechanism. The resonance field was also measured as a function of orientation and the results were fitted, exhibiting a good consistence.