• Investigative Magnetic Resonance Imaging
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• v.13 no.1
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• pp.47-53
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• 2009

Purpose : Although it's been known for half a century that unique structures have evolved in the cerebellum and they then became greatly enlarged in the human brain, the function of these structures still remains unknown. The purpose of this study was to assess cerebellar activation during motor, sensory, word generation, listening comprehension, and working memory tasks with using functional magnetic resonance imaging (fMRI). Materials and Methods : Eleven healthy right-handed subjects (Male: female, 6:5, mean age: 27.4years) were imaged on a Siemens 1.5T scanner. Whole brain functional maps were acquired using BOLD EPI sequences in the axial plane. Each paradigm consisted of five epochs of activation vs. the control condition. The activation tasks consisted of left finger complex movement, sensory stimulation of the left hand, word generation, listening comprehension, and working memory tasks. The reference function was a boxcar waveform. The activation maps were thresholded at p = 0.001. SPM 5 evaluated the activated areas and responses within the cerebellum. Results : Cerebellar activation was observed on motor task, word generation task, and working memory task. There were 949 activated areas and the mean fitted and adjusted response was 0.68 during the motor task. There were 319 activated areas and the mean fitted and adjusted response was 0.15 during the word generation task. There were 330 activated areas and the mean fitted and adjusted response was 0.26 during the working memory task. Conclusion : Our results suggest that the cerebellum is involved in a variety of functional tasks, including motor, word generation, and working memory tasks. However, during the motor task, the cerebellum showed a large activated area and a high response. Cerebellar function can be evaluated by fMRI.

• Korean Journal of Biological Psychiatry
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• v.19 no.2
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• pp.71-76
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• 2012

Objectives : Novelty seeking (NS) represents a dopaminergically modulated tendency toward frequent exploratory activity. Considering the reports showing the relationship between exploratory activity and amygdalar function and structure, and the fact that amygdala is one of the key structures that constitute the dopaminergic pathway in the brain, amygdala might be closely related to NS tendencies. Amygdalar subregional analysis method, which has the enhanced sensitivity compared to the volumteric approach would be appropriate in investigating the subtle differences of amygdalar structures among healthy individuals. The aim of the current study was to examine whether amygdalar subregional morphometric characteristics are associated with the NS tendencies in healthy adults using the amygdalar subregional analysis method. Methods : Twenty-six healthy adults (12 males, 14 females ; mean age $29.8{\pm}6.2$ years) were screened for eligibility. All subjects completed the Korean version of the Temperament and Character Inventory (TCI) and underwent high-resolution brain magnetic resonance imaging. Individuals were divided into 2 groups according to NS scores of the TCI. Results : Individuals of the high NS group had significantly larger laterobasal subregions in right amygdala, after adjustment with the brain parenchymal volumes. Sensitivity analyses for each potential confounding factor such as age, education years and Hamilton Depression Rating Scale (HDRS) scores demonstrated consistent results. Conclusions : This study suggests that NS differences are associated with the laterobasal subregion of the amygdala.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.1
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• pp.112-119
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• 2011

Sheaths are arranged in the web and lower part of prestressed-concrete girder bridges, and prestressing wires and concrete are indirectly bonded together by filling interior parts of the sheaths. However, when the filling is not sufficient, water can penetrate the interior parts of the sheaths and, thereby, prestressing wires can be corroded or transverse cracks would occur around sheaths by the freezing and thawing action of the penetrated water. Therefore, it is an important element in maintenance management of structures to find out the sheaths unfilled with grout early after construction. In this paper, in order not to damage bridge members, the impact-echo method with a new approach in application is used to probe sheaths unfilled with grout for real structures. The location of sheaths is first estimated with reinforcing bar probing instrument of radar type and the measurement locations of sheaths are determined. By sending elastic wave to the side of girders and receiving the response, the location of the unfilled part of a sheath was estimated from the difference between high frequency peak and twice the resonance frequency indicating thickness. To verify the location of void estimated by the impact-echo method, pictures were taken by an industrial fiber scope after drilling a hole.

• Journal of Trauma and Injury
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• v.30 no.4
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• pp.158-165
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• 2017

Purpose: The purpose of this study was to evaluate the diagnostic accuracy of X-rays in patients with acute traumatic vertebral fractures visiting the emergency department and to analyze the diagnostic value of X-rays for each spine level. Methods: We retrospectively analyzed basal characteristics by reviewing medical records of 363 patients with adult traumatic vertebral fractures, admitted to the emergency center from March 1, 2014 to February 28, 2017. We analyzed spine X-rays and magnetic resonance imaging (MRI) scans to determine distribution according to the vertebral level, and we evaluated the efficacy of X-rays by comparing discrepancies between X-rays and MRI scans. Results: For a total of 363 patients, the mean age was 56.65 (20-93) and 214 (59%) were males. On the basis of X-rays, 67 cases (15.1%) were of the cervical spine, 133 cases (30.0%) were of the thoracic spine, and 243 cases (54.9%) were of the lumbar spine. In particular, the thoracolumbar region (T11-L2) was the most common, with 260 cases (58.7%). In X-rays, fractures were the least in the upper thoracic region (T1-T3), whereas MRI scans revealed fairly uniform distribution across the thoracic spine. Sensitivity of X-rays was lowest in the upper thoracic spine and specificity was almost always greater than 98%, except for 94.7% in L1. Positive predictive value was lower in the mid-thoracic region (T4-T9) and negative predictive value was slightly lower in C6, T2, and T3 than at other sites. Diagnostic accuracy of X-rays by vertebral body, transverse process, and spinous process according to fractured vertebral structures was significantly different according to vertebral level. Conclusions: Diagnostic accuracy of X-rays was lower in the upper thoracic region than in other parts. Further studies are needed to identify better methods for diagnosis considering cost and neurological prognosis.

• Journal of IKEEE
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• v.12 no.3
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• pp.138-143
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• 2008

In this study, we propose that the structures of spiral inductors have the environment advantage utilizing direct-write and LAM(Laser Ablation of Microparticles) processes without process step of lithography and etching etc. of existing semiconductor process. The structures of inductors have Si thickness of 540${\mu}m$, $SiO_2$ thickness of 3${\mu}m$. The width of Cu coils and the space between segments have 30${\mu}m$, respectively, using for direct-write and LAM processes. The performance of spiral planar inductors was simulated to frequency characteristics for inductance, quality-factor, SRF(Self- Resonance Frequency) using HFSS. The inductors without underpass and via have inductance of 1.11nH over the frequency range of 300 to 800 MHz, quality-factor of maximum 38 at 5 GHz, SRF of 18 GHz. Otherwise, inductors with underpass and via have inductance of 1.12nH over the frequency range of 300 to 800 MHz, quality-factor of maximum 35 at 5 GHz, SRF of 16 GHz.

• Journal of the Earthquake Engineering Society of Korea
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• v.10 no.6 s.52
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• pp.133-135
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• 2006

We propose and fabricate a novel fiber optic sensor for the detection of abnormal structural signals from various constructions. It's advantages are highly sensitive. small in dimension and electro-magnetic immune. Since this sensor was simply constructed with a single-mode fiber at infra-red wavelength and a laser-diode with the wavelength of 625 nm, the modes in the end of the optical fiber were not show as Gaussian distributed. So, we used the change of the mode distribution to get the sensor output by the external abnormal effect of structures. We investigated the resonance by performing the bending test of an aluminum beam attached with the fiber sensor. In the test, we could obtained a feasible signal to sense the abnormal condition of structures.

• Bulletin of the Korean Chemical Society
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• v.33 no.8
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• pp.2508-2512
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• 2012

Cold shock proteins (CSPs) are a family of proteins induced at low temperatures. CSPs bind to single-stranded nucleic acids through the ribonucleoprotein 1 and 2 (RNP 1 and 2) binding motifs. CSPs play an essential role in cold adaptation by regulating transcription and translation via molecular chaperones. The solution nuclear magnetic resonance (NMR) or X-ray crystal structures of several CSPs from various microorganisms have been determined, but structural characteristics of psychrophilic CSPs have not been studied. Therefore, we optimized the purification process to obtain highly pure Lm-Csp and determined the three-dimensional structure model of Lm-Csp by comparative homology modeling using MODELLER on the basis of the solution NMR structure of Bs-CspB. Lm-Csp consists of a ${\beta}$-barrel structure, which includes antiparallel ${\beta}$ strands (G4-N10, F15-I18, V26-H29, A46-D50, and P58-Q64). The template protein, Bs-CspB, shares a similar ${\beta}$ sheet structure and an identical chain fold to Lm-Csp. However, the sheets in Lm-Csp were much shorter than those of Bs-CspB. The Lm-Csp side chains, E2 and R20 form a salt bridge, thus, stabilizing the Lm-Csp structure. To evaluate the contribution of this ionic interaction as well as that of the hydrophobic patch on protein stability, we investigated the secondary structures of wild type and mutant protein (W8, F15, and R20) of Lm-Csp using circular dichroism (CD) spectroscopy. The results showed that solvent-exposed aromatic side chains as well as residues participating in ionic interactions are very important for structural stability. Further studies on the three-dimensional structure and dynamics of Lm-Csp using NMR spectroscopy are required.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.6
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• pp.43-50
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• 2010

In this paper, we analyzed radiated emission generated by the split power/ground plane structures in order to reduce EMI in system modules. The magnetic fields and electric fields were simulated and measured on the test boards under various conditions. In order to reduce radiated emission, we have to determine spacing and location of the split ground gap so that input signal frequency does not coincide with the resonance frequency of the split power/ground plane structure and the phase of reflection coefficient is close to $0^{\circ}$ at input signal frequency. Moreover, we found that inserting a stitching capacitor could reduce the radiated emission. Low magnitude of reflection coefficient and the phase close to $0^{\circ}$ are required to reduce radiated emission. It is necessary to properly decide value and location of a stitching capacitor to fulfil those requirements.

• Geomechanics and Engineering
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• v.22 no.3
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• pp.245-254
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• 2020

The interaction between the frozen soil and building structures deteriorates with the increasing temperature. A nuclear magnetic resonance (NMR) stratification test was conducted with respect to the unfrozen water content on the interface and a shear test was conducted on the frozen soil-structure interface to explore the shear characteristics of the frozen soil-structure interface and its failure mechanism during the thawing process. The test results showed that the unfrozen water at the interface during the thawing process can be clearly distributed in three stages, i.e., freezing, phase transition, and thawing, and that the shear strength of the interface decreases as the unfrozen water content increases. The internal friction angle and cohesive force display a change law of "as one falls, the other rises," and the minimum internal friction angle and maximum cohesive force can be observed at -1℃. In addition, the change characteristics of the interface strength parameters during the freezing process were compared, and the differences between the interface shear characteristics and failure mechanisms during the frozen soil-structure interface freezing-thawing process were discussed. The shear strength parameters of the interface was subjected to different changes during the freezing-thawing process because of the different interaction mechanisms of the molecular structures of ice and water in case of the ice-water phase transition of the test sample during the freezing-thawing process.

• Journal of Power System Engineering
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• v.15 no.1
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• pp.24-31
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• 2011

Rectangular box type structures are used in many fields of civil, mechanical and marine engineering. Especially, Most ship structures are often in contact with inner or outer fluid, like ballast, fuel and stem tanks. Fatigue damages are sometimes observed in these tanks which seem to be caused by resonance with exciting force of engine and propeller. Vibration characteristics of these thin walled tanks in contact with fluid near engine and propeller are strongly affected by added mass of containing fluid. Therefore it is essentially important to estimate the added mass effect to predict vibration of the tanks. Many authors have studied vibration of rectangular tanks containing fluid. Few research on dynamic interaction among tank walls filled with fluid are reported in the vibration of rectangular tanks recently. In case of rectangular tanks, structural coupling between adjacent panels and effect of vibration modes of multiple panels on added mass of water have to be considered. In the previous report, a numerical analysis is performed for the coupling effect between panels of a tank on added mass of containing fluid, the effect of structural constraint between panels on each vibration mode for fluid region, and mode characteristics in accordance with changing breadth of the plates by using finite element method for plates and boundary element method for fluid region. In this paper, the coupling effect between panels of a tank on added mass of containing fluid, the effect of structural constraint between panels on each vibration mode for fluid region, and mode characteristics in accordance with changing length, thickness, and boundary condition of the plates are investigated numerically and discussed.