• Phonetics and Speech Sciences
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• v.13 no.3
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• pp.1-13
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• 2021

This study examined the characteristics of linguistic prosody in terms of cerebral lateralization in three groups of 9 healthy speakers and 14 speakers with a history of stroke (7 with left hemisphere damage (LHD), 7 with right hemisphere damage (RHD)). Specifically, prosodic characteristics related to speech rate, duration, pitch, and intensity were examined in three types of interrogative sentences (wh-questions, yes-no questions, alternative questions) with auditory perceptual evaluation. As a result, the statistically significant key variables showed flaws in production of the linguistic prosody in the speakers with LHD. The statistically significant variables were more insufficiently produced for wh-questions than for yes-no and alternative questions. This trend was particularly noticeable in variables related to pitch and speech rate. This result suggests that when Korean speakers process linguistic prosody, such as that of lexico-semantic and syntactic information in interrogative sentences, the left hemisphere seems to be superior to the right hemisphere.

• Knowledge Management Research
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• v.6 no.1
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• pp.85-103
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• 2005

The purpose of this study was to identify the relationship between fixation and brain preference. Based on the hemisphere asymmetric theory and fixation, two hypotheses were articulated. They were: 1) Right-brain preference is negatively related to divergent fixation. 2) Left-brain preference is negatively related to convergent fixation. A self-reporting scale for measuring the brain preference with 42 items were developed for the study based on functional characteritics of left and right hemisphere. Samples were collected from 579 college students in K University. Regression analysis showed that right-brain preference was negatively associated with divergent fixation. In the relationship between left-brain preference and convergent fixation, mixed results were produced. Research implication were discussed at the end of the study.

• Publications of The Korean Astronomical Society
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• v.8 no.1
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• pp.153-161
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• 1993

We analyze 211 data of the daily sunspot observations during the period of January 4 to November 30 in 1993 and present the daily relative sunspot numbers. During 334 days of the period, the preliminary annual average of the relative sunspot numbers is found to be 61.8 based on 27.1 distinct spots in a single group for 3.7 spot groups. According to the appearance of 203 spot groups, our analysis shows that the mean life time of spot group is about 1 day and 15.5 hours. Our records show that more number of sunspots have appeared in the southern hemisphere than in the northern hemisphere by some 2%, indicating that the solar activities of the northern and southern hemisphere are much the same during the period.

• Atmosphere
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• v.18 no.4
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• pp.429-439
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• 2008

The lower-stratospheric polar temperature in winter and spring for both hemispheres is investigated based on the NCEP/NCAR 50-year reanalysis data with respect to the strength of the stratospheric eddy heat flux. Both the polar temperature and the eddy heat flux show significant variation on the decadal and year-to-year time scales except during the Southern Hemisphere winter. The year-to-year variation in the polar temperature is mainly determined by the eddy heat flux convergence. The eddy heat flux convergence is compared with the diabatic heating rate obtained from a two-dimensional model. Radiative heating caused by absorption of solar radiation is comparable to the heating caused by the eddy heat flux convergence in the Southern Hemisphere. The effect of ozone depletion on diabatic heating has been found to be secondary in the Northern Hemisphere, even in March 1997 when the record depletion of ozone took place.

• Transactions of the Society of Information Storage Systems
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• v.9 no.2
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• pp.48-50
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• 2013

In this work, we investigated the diffraction of inverse-hemisphere shaped polymer grating. The grating was fabricated by using soft lithography of hexagonally close-packed PS nanospheres. The periodicity of the grating was tuned by swelling in acetone and the diffraction wavelength shift induced from lattice change was measured. This device can be used as a strain gauge or a chemical sensor.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.6
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• pp.795-801
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• 2019

The aim of this study was to investigate the possibility of the skin-friction reduction by vortex control. A vortical system such as a horseshoe vortex, a hairpin vortex, and a wake region was induced around a hemisphere attached on a Perspex flat plate in the circulating water channel. Hairpin vortices were developed from the wake region and horseshoe vortices were formed by an adverse pressure gradient in front of the hemisphere. The horseshoe vortices located on the flank of the hemisphere induced a high momentum flow in the wake region by the direction of their vorticity. This process increased the frequency of the hairpin vortices as well as the frictional drag on the surface of the wake region. To reduce the skin-friction drag, suction control in front of the hemisphere was applied through a hole. Flow visualization was performed to optimize the free-stream velocity, size of the hemisphere, and size of the suction hole. Once the wall suction control mitigated the strength of the horseshoe vortex, the energy supplied to the wake region was reduced, causing the frequency of the hairpin vortex generation to decrease by 36.4 %. In addition, the change in the skin-friction drag, which was measured with a dynamometer connected to a plate in the wake region, also decreased by 2.3 %.

• Korean Journal of Psychosomatic Medicine
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• v.6 no.1
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• pp.79-84
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• 1998

Authors report a case of poststroke bipolar disorder that occurs much less frequently than poststroke depression(PSD). A MRI study performed to identify the etiology of a secondary manic episode in a patient with preceded PSD after left basal ganglia infarction revealed newly developed right basal ganglia infarction associated with poststroke bipolar disorder. It is interesting to note that (1) the temporal relationship was found between the occurrence of PSD after left hemisphere stroke and the occurrence of poststroke bipolar disorder following right hemisphere stroke, and that (2) the occurrence of PSD and the occurrence of poststroke bipolar disorder are associated with lesion location respectively. It has been reported that bipolar disorders were associated with subcortical lesions of the right hemisphere, whereas right-cortical lesions led to unipolar mania and that risk factors for mania included a family history of psychiatric disorders and mild subcortical atrophy. In this case, MR image shows subcortical lesions of the right hemisphere and mild subcortical atrophy. The investigation of the relationships among stroke lesion locations and potstroke mood disorders and risk factors for poststroke bipolar disorder may contribute to understanding the neurobiology of primary mood disorder. A clinical implication is that the risk of secondary bipolar disorder after cerebral infarction should be highlighted.

• Economic and Environmental Geology
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• v.22 no.2
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• pp.167-171
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• 1989

Palaeomagnetic studies accompany calculation and plotting of pole position. This paper explains three graphical methods for the determination of pole position and plotting problem. It also derives the numerical formula for pole calculation and explains the method how the pole plotted on the rear hemisphere can be transformed to the frontal hemisphere, which is not clarified elsewhere.

• The Journal of Korean Physical Therapy
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• v.26 no.3
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• pp.216-219
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• 2014

Purpose: We presented with a patient with traumatic brain injury who showed a transcallosal ipsilateral motor pathway from unaffected motor cortex to affected extremities, as evaluated by diffusion tensor tractography (DTT). Methods: One patient and six age-matched normal subjects were enrolled. A 42-year-old left hemiparetic male who suffered from brain injury by motor vehicle accident 9 years ago showed a leukomalactic lesion in the right corona radiata and parieto-temporal lobe. His left extremities were completely paralyzed initially, but recovered slowly over 2 years. At the time of the evaluation, he was able to grasp and release an object, and to walk with spastic gait pattern. DTT was performed using 1.5 T with a Synergy-L Sensitivity Encoding head coil. DTT was obtained with termination criteria of FA <0.2 and an angle change > $45^{\circ}c$. Results: The motor tracts of the unaffected (left) hemisphere of the patient and control subjects originated from the motor cortex and descended along the known corticospinal tract without any transcallosal tract. By contrast, the tract of the affected (right) hemisphere originated from the left premotor cortex, descended through the left corona radiata, and then crossed the mid-portion of the corpus callosum. The tract then descended through the known corticospinal tract pathway to the right medulla. Conclusion: We conclude that the transcallosal ipsilateral motor pathway from the unaffected hemisphere appeared to contribute to the motor recovery in this patient.

• Journal of the Korean Society of Physical Medicine
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• v.6 no.3
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• pp.361-368
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• 2011

Purpose : The aims of this study was to identify the activation of the mirror neuron system during action observation in people with stroke and the difference between left hemisphere and right hemisphere and to provide possibility of the use of action observation as a clinical method for improving motor function after stroke. Methods : Seventeen participants were asked to observe 3 different stimulation conditions for 80 seconds. A 30 second rest period was given between stimulations. Electroencephalogram(EEG) signals from electrodes on the participant's scalp were recorded during action observation. The activation of the mirror neuron system(MNS) between the picture observation condition and action observation condition was compared with a paired t-test. An independent t-test was used to compare difference between C3 and C4 on the activation of the mirror neuron system in the action observation condition. Results : Result of paired t-test showed a significantly decreased log ratio in the activation of the mirror neuron system in the action observation condition compared to the picture observation condition. Result of the independent t-test indicated no significant differences in the activation of the mirror neuron system in the right and left hemisphere. Conclusion : The mirror neuron system showed greater activation in the action observation condition than in the picture observation condition and activation in the both hemisphere during action observation. We conclude that these findings suggest that this may possibly be an efficient clinical intervention method for improving motor function.