메뉴 건너뛰기




Volumn 33, Issue 2, 2011, Pages 338-348

Preparation and performance of obstacle steps: Interaction between brain and spinal neuronal activity

Author keywords

Brain activity; EEG; Locomotion; Motor performance; Obstacle stepping; Spinal neuronal activity

Indexed keywords

ADULT; ARM MUSCLE; ARTICLE; BRAIN FUNCTION; CONTROLLED STUDY; ELECTROENCEPHALOGRAPHY; ELECTROMYOGRAPHY; FLEXOR MUSCLE; FRONTAL GYRUS; HUMAN; HUMAN EXPERIMENT; LEG MUSCLE; LOCOMOTION; MUSCLE CONTRACTION; NERVE STIMULATION; NORMAL HUMAN; OBSTACLE SWING; ORBITAL CORTEX; PREFRONTAL CORTEX; PRIORITY JOURNAL; RIGHT HEMISPHERE; SPINAL REFLEX; STANDING; TASK PERFORMANCE; TIBIAL NERVE; TREADMILL; VISION; WALKING;

EID: 78651447824     PISSN: 0953816X     EISSN: 14609568     Source Type: Journal    
DOI: 10.1111/j.1460-9568.2010.07494.x     Document Type: Article
Times cited : (51)

References (54)
  • 2
    • 0023927670 scopus 로고
    • Discharges of interpositus and Purkinje cells of the cat cerebellum during locomotion under different conditions
    • Armstrong, D.M. & Edgley, S.A. (1988) Discharges of interpositus and Purkinje cells of the cat cerebellum during locomotion under different conditions. J. Physiol., 400, 425-445.
    • (1988) J. Physiol. , vol.400 , pp. 425-445
    • Armstrong, D.M.1    Edgley, S.A.2
  • 3
    • 0000369173 scopus 로고
    • Facts and Concepts
    • Gurfinkel, V., Joffe, M.E., Massion, J. &, Roll, J.P. (Eds), Plenum Press, New York
    • Beloozerova, J.N. & Sirota, M.G. (1988) Role of motor cortex in control of locomotion. In Gurfinkel, V., Joffe, M.E., Massion, J. & Roll, J.P. (Eds), Facts and Concepts. Plenum Press, New York, pp. 163-176.
    • (1988) Role of motor cortex in control of locomotion , pp. 163-176
    • Beloozerova, J.N.1    Sirota, M.G.2
  • 4
    • 0027992545 scopus 로고
    • A spatio-temporal dipole model of the readiness potential in humans. II. Foot movement
    • Bocker, K.B., Brunia, C.H. & Cluitmans, P.J. (1994) A spatio-temporal dipole model of the readiness potential in humans. II. Foot movement. Electroencephalogr. Clin. Neurophysiol., 91, 286-294.
    • (1994) Electroencephalogr. Clin. Neurophysiol. , vol.91 , pp. 286-294
    • Bocker, K.B.1    Brunia, C.H.2    Cluitmans, P.J.3
  • 5
    • 53149136604 scopus 로고    scopus 로고
    • Bilateral motor resonance evoked by observation of a one-hand movement: role of the primary motor cortex
    • Borroni, P., Montagna, M., Cerri, G. & Baldissera, F. (2008) Bilateral motor resonance evoked by observation of a one-hand movement: role of the primary motor cortex. Eur. J. Neurosci., 28, 1427-1435.
    • (2008) Eur. J. Neurosci. , vol.28 , pp. 1427-1435
    • Borroni, P.1    Montagna, M.2    Cerri, G.3    Baldissera, F.4
  • 7
    • 34250757050 scopus 로고    scopus 로고
    • The gateway hypothesis of rostral prefrontal cortex (area 10) function
    • Burgess, P.W., Dumontheil, I. & Gilbert, S.J. (2007) The gateway hypothesis of rostral prefrontal cortex (area 10) function. Trends Cogn. Sci., 11, 290-298.
    • (2007) Trends Cogn. Sci. , vol.11 , pp. 290-298
    • Burgess, P.W.1    Dumontheil, I.2    Gilbert, S.J.3
  • 8
    • 0033038188 scopus 로고    scopus 로고
    • Studies on the corticospinal control of human walking. I. Responses to focal transcranial magnetic stimulation of the motor cortex
    • Capaday, C., Lavoie, B.A., Barbeau, H., Schneider, C. & Bonnard, M. (1999) Studies on the corticospinal control of human walking. I. Responses to focal transcranial magnetic stimulation of the motor cortex. J Neurophysiol, 81, 129-139.
    • (1999) J Neurophysiol , vol.81 , pp. 129-139
    • Capaday, C.1    Lavoie, B.A.2    Barbeau, H.3    Schneider, C.4    Bonnard, M.5
  • 9
    • 0021369398 scopus 로고
    • Cutaneous nerve stimulation and motoneuronal excitability. II: evidence for non-segmental influences
    • Delwaide, P.J. & Crenna, P. (1984) Cutaneous nerve stimulation and motoneuronal excitability. II: evidence for non-segmental influences. J. Neurol. Neurosurg. Psychiatr., 47, 190-196.
    • (1984) J. Neurol. Neurosurg. Psychiatr. , vol.47 , pp. 190-196
    • Delwaide, P.J.1    Crenna, P.2
  • 10
    • 0036752509 scopus 로고    scopus 로고
    • Do human bipeds use quadrupedal coordination?
    • Dietz, V. (2002) Do human bipeds use quadrupedal coordination? Trends Neurosci., 25, 462-467.
    • (2002) Trends Neurosci. , vol.25 , pp. 462-467
    • Dietz, V.1
  • 11
    • 44549089034 scopus 로고    scopus 로고
    • Body weight supported gait training: from laboratory to clinical setting
    • Dietz, V. (2008) Body weight supported gait training: from laboratory to clinical setting. Brain Res. Bull., 76, 459-463.
    • (2008) Brain Res. Bull. , vol.76 , pp. 459-463
    • Dietz, V.1
  • 12
    • 58149125354 scopus 로고    scopus 로고
    • Locomotion in Parkinson's disease: neuronal coupling of upper and lower limbs
    • Dietz, V. & Michel, J. (2008) Locomotion in Parkinson's disease: neuronal coupling of upper and lower limbs. Brain, 131, 3421-3431.
    • (2008) Brain , vol.131 , pp. 3421-3431
    • Dietz, V.1    Michel, J.2
  • 13
    • 0021924758 scopus 로고
    • Cerebral potentials and leg muscle e.m.g. responses associated with stance perturbation
    • Dietz, V., Quintern, J., Berger, W. & Schenck, E. (1985) Cerebral potentials and leg muscle e.m.g. responses associated with stance perturbation. Exp. Brain Res., 57, 348-354.
    • (1985) Exp. Brain Res. , vol.57 , pp. 348-354
    • Dietz, V.1    Quintern, J.2    Berger, W.3    Schenck, E.4
  • 14
    • 0036825096 scopus 로고    scopus 로고
    • Contributions of the motor cortex to the control of the hindlimbs during locomotion in the cat
    • Drew, T., Jiang, W. & Widajewicz, W. (2002) Contributions of the motor cortex to the control of the hindlimbs during locomotion in the cat. Brain Res. Brain Res. Rev., 40, 178-191.
    • (2002) Brain Res. Brain Res. Rev. , vol.40 , pp. 178-191
    • Drew, T.1    Jiang, W.2    Widajewicz, W.3
  • 15
    • 0032746264 scopus 로고    scopus 로고
    • Stance perturbation-evoked potentials in old people with poor gait and balance
    • Duckrow, R.B., Abu-Hasaballah, K., Whipple, R. & Wolfson, L. (1999) Stance perturbation-evoked potentials in old people with poor gait and balance. Clin. Neurophysiol., 110, 2026-2032.
    • (1999) Clin. Neurophysiol. , vol.110 , pp. 2026-2032
    • Duckrow, R.B.1    Abu-Hasaballah, K.2    Whipple, R.3    Wolfson, L.4
  • 16
    • 0025168763 scopus 로고
    • Gating and reversal of reflexes in ankle muscles during human walking
    • Duysens, J., Trippel, M., Horstmann, G.A. & Dietz, V. (1990) Gating and reversal of reflexes in ankle muscles during human walking. Exp. Brain Res., 82, 351-358.
    • (1990) Exp. Brain Res. , vol.82 , pp. 351-358
    • Duysens, J.1    Trippel, M.2    Horstmann, G.A.3    Dietz, V.4
  • 17
    • 0027246185 scopus 로고
    • Increased amplitude of cutaneous reflexes during human running as compared to standing
    • Duysens, J., Tax, A.A., Trippel, M. & Dietz, V. (1993) Increased amplitude of cutaneous reflexes during human running as compared to standing. Brain Res., 613, 230-238.
    • (1993) Brain Res. , vol.613 , pp. 230-238
    • Duysens, J.1    Tax, A.A.2    Trippel, M.3    Dietz, V.4
  • 18
    • 0035396110 scopus 로고    scopus 로고
    • Obstacle avoidance during human walking: learning rate and cross-modal transfer
    • Erni, T. & Dietz, V. (2001) Obstacle avoidance during human walking: learning rate and cross-modal transfer. J. Physiol., 534, 303-312.
    • (2001) J. Physiol. , vol.534 , pp. 303-312
    • Erni, T.1    Dietz, V.2
  • 19
    • 0000423735 scopus 로고
    • Handbook of Physiology. The Nervous System. Motor Control
    • Brooks, V. (Ed.), American Physiological Society, Washington, DC
    • Grillner, S. (1981) Control of locomotion in bipeds tetrapods and fish. In Brooks, V. (Ed.), Handbook of Physiology. The Nervous System. Motor Control. American Physiological Society, Washington, DC, pp. 1179-1236.
    • (1981) Control of locomotion in bipeds tetrapods and fish , pp. 1179-1236
    • Grillner, S.1
  • 20
    • 33847642077 scopus 로고    scopus 로고
    • The effect of voluntary arm abduction on balance recovery following multidirectional stance perturbations
    • Grin, L., Frank, J. & Allum, J.H. (2007) The effect of voluntary arm abduction on balance recovery following multidirectional stance perturbations. Exp. Brain Res., 178, 62-78.
    • (2007) Exp. Brain Res. , vol.178 , pp. 62-78
    • Grin, L.1    Frank, J.2    Allum, J.H.3
  • 21
    • 3042530850 scopus 로고    scopus 로고
    • Obstacle avoidance during human walking: effects of biomechanical constraints on performance
    • van Hedel, H.J. & Dietz, V. (2004) Obstacle avoidance during human walking: effects of biomechanical constraints on performance. Arch. Phys. Med. Rehabil., 85, 972-979.
    • (2004) Arch. Phys. Med. Rehabil. , vol.85 , pp. 972-979
    • van Hedel, H.J.1    Dietz, V.2
  • 22
    • 0036713034 scopus 로고    scopus 로고
    • Obstacle avoidance during human walking: transfer of motor skill from one leg to the other
    • van Hedel, H.J., Biedermann, M., Erni, T. & Dietz, V. (2002) Obstacle avoidance during human walking: transfer of motor skill from one leg to the other. J. Physiol., 543, 709-717.
    • (2002) J. Physiol. , vol.543 , pp. 709-717
    • van Hedel, H.J.1    Biedermann, M.2    Erni, T.3    Dietz, V.4
  • 23
    • 0015817463 scopus 로고
    • Electrical signs of selective attention in the human brain
    • Hillyard, S.A., Hink, R.F., Schwent, V.L. & Picton, T.W. (1973) Electrical signs of selective attention in the human brain. Science, 182, 177-180.
    • (1973) Science , vol.182 , pp. 177-180
    • Hillyard, S.A.1    Hink, R.F.2    Schwent, V.L.3    Picton, T.W.4
  • 24
    • 53149127289 scopus 로고    scopus 로고
    • Corticospinal inhibition of transmission in propriospinal-like neurones during human walking
    • Iglesias, C., Nielsen, J.B. & Marchand-Pauvert, V. (2008) Corticospinal inhibition of transmission in propriospinal-like neurones during human walking. Eur. J. Neurosci., 28, 1351-1361.
    • (2008) Eur. J. Neurosci. , vol.28 , pp. 1351-1361
    • Iglesias, C.1    Nielsen, J.B.2    Marchand-Pauvert, V.3
  • 26
    • 3242728780 scopus 로고    scopus 로고
    • Brain activation patterns during imagined stance and locomotion in functional magnetic resonance imaging
    • Jahn, K., Deutschlander, A., Stephan, T., Strupp, M., Wiesmann, M. & Brandt, T. (2004) Brain activation patterns during imagined stance and locomotion in functional magnetic resonance imaging. Neuroimage, 22, 1722-1731.
    • (2004) Neuroimage , vol.22 , pp. 1722-1731
    • Jahn, K.1    Deutschlander, A.2    Stephan, T.3    Strupp, M.4    Wiesmann, M.5    Brandt, T.6
  • 27
    • 0034307938 scopus 로고    scopus 로고
    • Removal of eye activity artifacts from visual event-related potentials in normal and clinical subjects
    • Jung, T.P., Makeig, S., Westerfield, M., Townsend, J., Courchesne, E. & Sejnowski, T.J. (2000) Removal of eye activity artifacts from visual event-related potentials in normal and clinical subjects. Clin. Neurophysiol., 111, 1745-1758.
    • (2000) Clin. Neurophysiol. , vol.111 , pp. 1745-1758
    • Jung, T.P.1    Makeig, S.2    Westerfield, M.3    Townsend, J.4    Courchesne, E.5    Sejnowski, T.J.6
  • 28
    • 33744901157 scopus 로고    scopus 로고
    • Locomotor circuits in the mammalian spinal cord
    • Kiehn, O. (2006) Locomotor circuits in the mammalian spinal cord. Annu. Rev. Neurosci., 29, 279-306.
    • (2006) Annu. Rev. Neurosci. , vol.29 , pp. 279-306
    • Kiehn, O.1
  • 29
    • 76549209587 scopus 로고
    • [Changes in the Brain Potential in Voluntary Movements and Passive Movements in Man: Readiness Potential and Reafferent Potentials.]
    • Kornhuber, H.H. & Deecke, L. (1965) [Changes in the Brain Potential in Voluntary Movements and Passive Movements in Man: Readiness Potential and Reafferent Potentials.]. Pflugers Arch. Gesamte Physiol. Menschen Tiere, 284, 1-17.
    • (1965) Pflugers Arch. Gesamte Physiol. Menschen Tiere , vol.284 , pp. 1-17
    • Kornhuber, H.H.1    Deecke, L.2
  • 30
    • 33749522237 scopus 로고    scopus 로고
    • Plasticity of spinal cord reflexes after a complete transection in adult rats: relationship to stepping ability
    • Lavrov, I., Gerasimenko, Y.P., Ichiyama, R.M., Courtine, G., Zhong, H., Roy, R.R. & Edgerton, V.R. (2006) Plasticity of spinal cord reflexes after a complete transection in adult rats: relationship to stepping ability. J. Neurophysiol., 96, 1699-1710.
    • (2006) J. Neurophysiol. , vol.96 , pp. 1699-1710
    • Lavrov, I.1    Gerasimenko, Y.P.2    Ichiyama, R.M.3    Courtine, G.4    Zhong, H.5    Roy, R.R.6    Edgerton, V.R.7
  • 31
    • 34548299701 scopus 로고    scopus 로고
    • Facilitation of spinal reflexes assists performing but not learning an obstacle-avoidance locomotor task
    • Michel, J., van Hedel, H.J. & Dietz, V. (2007) Facilitation of spinal reflexes assists performing but not learning an obstacle-avoidance locomotor task. Eur. J. Neurosci., 26, 1299-1306.
    • (2007) Eur. J. Neurosci. , vol.26 , pp. 1299-1306
    • Michel, J.1    van Hedel, H.J.2    Dietz, V.3
  • 32
    • 41549155529 scopus 로고    scopus 로고
    • Obstacle stepping involves spinal anticipatory activity associated with quadrupedal limb coordination
    • Michel, J., van Hedel, H.J. & Dietz, V. (2008) Obstacle stepping involves spinal anticipatory activity associated with quadrupedal limb coordination. Eur. J. Neurosci., 27, 1867-1875.
    • (2008) Eur. J. Neurosci. , vol.27 , pp. 1867-1875
    • Michel, J.1    van Hedel, H.J.2    Dietz, V.3
  • 33
    • 0036136472 scopus 로고    scopus 로고
    • Nonparametric permutation tests for functional neuroimaging: a primer with examples
    • Nichols, T.E. & Holmes, A.P. (2002) Nonparametric permutation tests for functional neuroimaging: a primer with examples. Hum. Brain Mapp., 15, 1-25.
    • (2002) Hum. Brain Mapp. , vol.15 , pp. 1-25
    • Nichols, T.E.1    Holmes, A.P.2
  • 34
    • 0030976473 scopus 로고    scopus 로고
    • Evidence suggesting a transcortical pathway from cutaneous foot afferents to tibialis anterior motoneurones in man
    • Nielsen, J., Petersen, N. & Fedirchuk, B. (1997) Evidence suggesting a transcortical pathway from cutaneous foot afferents to tibialis anterior motoneurones in man. J. Physiol., 501(Pt 2), 473-484.
    • (1997) J. Physiol. , vol.501 , Issue.PART 2 , pp. 473-484
    • Nielsen, J.1    Petersen, N.2    Fedirchuk, B.3
  • 35
    • 0036454342 scopus 로고    scopus 로고
    • Standardized low-resolution brain electromagnetic tomography (sLORETA): technical details
    • Pascual-Marqui, R.D. (2002) Standardized low-resolution brain electromagnetic tomography (sLORETA): technical details. Methods Find. Exp. Clin. Pharmacol., 24(Suppl D), 5-12.
    • (2002) Methods Find. Exp. Clin. Pharmacol. , vol.24 , Issue.SUPPL D , pp. 5-12
    • Pascual-Marqui, R.D.1
  • 36
    • 0027998259 scopus 로고
    • Low resolution electromagnetic tomography: a new method for localizing electrical activity in the brain
    • Pascual-Marqui, R.D., Michel, C.M. & Lehmann, D. (1994) Low resolution electromagnetic tomography: a new method for localizing electrical activity in the brain. Int. J. Psychophysiol., 18, 49-65.
    • (1994) Int. J. Psychophysiol. , vol.18 , pp. 49-65
    • Pascual-Marqui, R.D.1    Michel, C.M.2    Lehmann, D.3
  • 37
    • 0036448284 scopus 로고    scopus 로고
    • Functional imaging with low-resolution brain electromagnetic tomography (LORETA): a review
    • Pascual-Marqui, R.D., Esslen, M., Kochi, K. & Lehmann, D. (2002) Functional imaging with low-resolution brain electromagnetic tomography (LORETA): a review. Methods Find. Exp. Clin. Pharmacol., 24(Suppl C), 91-95.
    • (2002) Methods Find. Exp. Clin. Pharmacol. , vol.24 , Issue.SUPPL C , pp. 91-95
    • Pascual-Marqui, R.D.1    Esslen, M.2    Kochi, K.3    Lehmann, D.4
  • 38
    • 0032967643 scopus 로고    scopus 로고
    • Dorsolateral prefrontal cortex: comparative cytoarchitectonic analysis in the human and the macaque brain and corticocortical connection patterns
    • Petrides, M. & Pandya, D.N. (1999) Dorsolateral prefrontal cortex: comparative cytoarchitectonic analysis in the human and the macaque brain and corticocortical connection patterns. Eur. J. Neurosci., 11, 1011-1036.
    • (1999) Eur. J. Neurosci. , vol.11 , pp. 1011-1036
    • Petrides, M.1    Pandya, D.N.2
  • 39
    • 0141788420 scopus 로고    scopus 로고
    • Functional imaging and pain: behavior, perception, and modulation
    • Porro, C.A. (2003) Functional imaging and pain: behavior, perception, and modulation. Neuroscientist, 9, 354-369.
    • (2003) Neuroscientist , vol.9 , pp. 354-369
    • Porro, C.A.1
  • 40
    • 24944439806 scopus 로고    scopus 로고
    • Quantification of motor cortex activity and full-body biomechanics during unconstrained locomotion
    • Prilutsky, B.I., Sirota, M.G., Gregor, R.J. & Beloozerova, I.N. (2005) Quantification of motor cortex activity and full-body biomechanics during unconstrained locomotion. J. Neurophysiol., 94, 2959-2969.
    • (2005) J. Neurophysiol. , vol.94 , pp. 2959-2969
    • Prilutsky, B.I.1    Sirota, M.G.2    Gregor, R.J.3    Beloozerova, I.N.4
  • 42
    • 0023257161 scopus 로고
    • Long-latency spinal reflex in man after flexor reflex afferent stimulation
    • Roby-Brami, A. & Bussel, B. (1987) Long-latency spinal reflex in man after flexor reflex afferent stimulation. Brain, 110(Pt 3), 707-725.
    • (1987) Brain , vol.110 , Issue.PART 3 , pp. 707-725
    • Roby-Brami, A.1    Bussel, B.2
  • 43
    • 0019774556 scopus 로고
    • Gating of somatosensory evoked potentials during different kinds of movement in man
    • Rushton, D.N., Rothwell, J.C. & Craggs, M.D. (1981) Gating of somatosensory evoked potentials during different kinds of movement in man. Brain, 104, 465-491.
    • (1981) Brain , vol.104 , pp. 465-491
    • Rushton, D.N.1    Rothwell, J.C.2    Craggs, M.D.3
  • 44
    • 0030955763 scopus 로고    scopus 로고
    • Corticospinal input in human gait: modulation of magnetically evoked motor responses
    • Schubert, M., Curt, A., Jensen, L. & Dietz, V. (1997) Corticospinal input in human gait: modulation of magnetically evoked motor responses. Exp. Brain Res., 115, 234-246.
    • (1997) Exp. Brain Res. , vol.115 , pp. 234-246
    • Schubert, M.1    Curt, A.2    Jensen, L.3    Dietz, V.4
  • 46
    • 33749603426 scopus 로고    scopus 로고
    • What is the Bereitschaftspotential?
    • Shibasaki, H. & Hallett, M. (2006) What is the Bereitschaftspotential? Clin. Neurophysiol., 117, 2341-2356.
    • (2006) Clin. Neurophysiol. , vol.117 , pp. 2341-2356
    • Shibasaki, H.1    Hallett, M.2
  • 47
    • 0019787962 scopus 로고
    • Cerebral potentials evoked by muscle stretch in man
    • Starr, A., McKeon, B., Skuse, N. & Burke, D. (1981) Cerebral potentials evoked by muscle stretch in man. Brain, 104, 149-166.
    • (1981) Brain , vol.104 , pp. 149-166
    • Starr, A.1    McKeon, B.2    Skuse, N.3    Burke, D.4
  • 48
    • 36549035665 scopus 로고    scopus 로고
    • Concept-based behavioral planning and the lateral prefrontal cortex
    • Tanji, J., Shima, K. & Mushiake, H. (2007) Concept-based behavioral planning and the lateral prefrontal cortex. Trends Cogn. Sci., 11, 528-534.
    • (2007) Trends Cogn. Sci. , vol.11 , pp. 528-534
    • Tanji, J.1    Shima, K.2    Mushiake, H.3
  • 51
    • 67649881618 scopus 로고    scopus 로고
    • Neuropathic pain in spinal cord injury: significance of clinical and electrophysiological measures
    • Wydenkeller, S., Maurizio, S., Dietz, V. & Halder, P. (2009) Neuropathic pain in spinal cord injury: significance of clinical and electrophysiological measures. Eur. J. Neurosci., 30, 91-99.
    • (2009) Eur. J. Neurosci. , vol.30 , pp. 91-99
    • Wydenkeller, S.1    Maurizio, S.2    Dietz, V.3    Halder, P.4
  • 52
    • 0025336833 scopus 로고
    • Phase-dependent reflex reversal in human leg muscles during walking
    • Yang, J.F. & Stein, R.B. (1990) Phase-dependent reflex reversal in human leg muscles during walking. J. Neurophysiol., 63, 1109-1117.
    • (1990) J. Neurophysiol. , vol.63 , pp. 1109-1117
    • Yang, J.F.1    Stein, R.B.2
  • 53
    • 34548748617 scopus 로고    scopus 로고
    • Enhancement of arm and leg locomotor coupling with augmented cutaneous feedback from the hand
    • Zehr, E.P., Klimstra, M., Dragert, K., Barzi, Y., Bowden, M.G., Javan, B. & Phadke, C. (2007) Enhancement of arm and leg locomotor coupling with augmented cutaneous feedback from the hand. J. Neurophysiol., 98, 1810-1814.
    • (2007) J. Neurophysiol. , vol.98 , pp. 1810-1814
    • Zehr, E.P.1    Klimstra, M.2    Dragert, K.3    Barzi, Y.4    Bowden, M.G.5    Javan, B.6    Phadke, C.7


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.