메뉴 건너뛰기




Volumn 22, Issue SUPPL. 1, 2011, Pages

Quickest detection of drug-resistant seizures: An optimal control approach

Author keywords

Bayesian estimation; Dynamic programming; Hidden Markov model; Intracranial electroencephalogram; Multivariate analysis; Networks; Optimal control; Quickest detection

Indexed keywords

ARTICLE; CASE REPORT; CONCEPTUAL FRAMEWORK; CONTROLLED STUDY; DRUG RESISTANCE; ELECTROENCEPHALOGRAM; EPILEPSY; FEMALE; HUMAN; MALE; PROBABILITY; SEIZURE;

EID: 83455230793     PISSN: 15255050     EISSN: 15255069     Source Type: Journal    
DOI: 10.1016/j.yebeh.2011.08.041     Document Type: Article
Times cited : (50)

References (65)
  • 1
    • 77954516774 scopus 로고    scopus 로고
    • Effects of direct brain stimulation depend on seizure dynamics
    • Jiruska P., Powell A.D., Deans J.K., Jefferys J.G. Effects of direct brain stimulation depend on seizure dynamics. Epilepsia 2010, 51:S93-S97.
    • (2010) Epilepsia , vol.51
    • Jiruska, P.1    Powell, A.D.2    Deans, J.K.3    Jefferys, J.G.4
  • 3
    • 33645057477 scopus 로고    scopus 로고
    • Brain stimulation for epilepsy: can scheduled or responsive neurostimulation stop seizures?
    • Morrell M. Brain stimulation for epilepsy: can scheduled or responsive neurostimulation stop seizures?. Curr Opin Neurol 2006, 19:164-168.
    • (2006) Curr Opin Neurol , vol.19 , pp. 164-168
    • Morrell, M.1
  • 4
    • 0017091353 scopus 로고
    • Automatic recognition and quantification of interictal epileptic activity in the human scalp EEG
    • Gotman J., Gloor P. Automatic recognition and quantification of interictal epileptic activity in the human scalp EEG. Electroencephalogr Clin Neurophysiol 1976, 41:513-529.
    • (1976) Electroencephalogr Clin Neurophysiol , vol.41 , pp. 513-529
    • Gotman, J.1    Gloor, P.2
  • 5
    • 0020382517 scopus 로고
    • Automatic recognition of epileptic seizures in the EEG
    • Gotman J. Automatic recognition of epileptic seizures in the EEG. Electroencephalogr Clin Neurophysiol 1982, 54:530-540.
    • (1982) Electroencephalogr Clin Neurophysiol , vol.54 , pp. 530-540
    • Gotman, J.1
  • 6
    • 0031748494 scopus 로고    scopus 로고
    • Real-time automated detection and quantitative analysis of seizures and short-term prediction of clinical onset
    • Osorio I., Frei M.G., Wilkinson S.B. Real-time automated detection and quantitative analysis of seizures and short-term prediction of clinical onset. Epilepsia 1998, 39:615-627.
    • (1998) Epilepsia , vol.39 , pp. 615-627
    • Osorio, I.1    Frei, M.G.2    Wilkinson, S.B.3
  • 7
    • 18744397821 scopus 로고    scopus 로고
    • Performance reassessment of a real-time seizure-detection algorithm on long ECoG series
    • Osorio I., Frei M.G., Giftakis J., et al. Performance reassessment of a real-time seizure-detection algorithm on long ECoG series. Epilepsia 2002, 43:1522-1535.
    • (2002) Epilepsia , vol.43 , pp. 1522-1535
    • Osorio, I.1    Frei, M.G.2    Giftakis, J.3
  • 8
    • 34250168707 scopus 로고    scopus 로고
    • Strategies for adapting automated seizure detection algorithms
    • Haas S.M., Frei M., Osorio I. Strategies for adapting automated seizure detection algorithms. Med Eng Phys 2007, 29:895-909.
    • (2007) Med Eng Phys , vol.29 , pp. 895-909
    • Haas, S.M.1    Frei, M.2    Osorio, I.3
  • 9
    • 70350620967 scopus 로고    scopus 로고
    • Real-time detection, quantification, warning, and control of epileptic seizures: the foundations for a scientific epileptology
    • Osorio I., Frei M.G. Real-time detection, quantification, warning, and control of epileptic seizures: the foundations for a scientific epileptology. Epilepsy Behav 2009, 16:391-396.
    • (2009) Epilepsy Behav , vol.16 , pp. 391-396
    • Osorio, I.1    Frei, M.G.2
  • 11
    • 13844280998 scopus 로고    scopus 로고
    • Continuous energy variation during the seizure cycle: towards an on-line accumulated energy
    • Esteller R., Echauz J., D'Alessandro M., et al. Continuous energy variation during the seizure cycle: towards an on-line accumulated energy. Clin Neurophysiol 2005, 116:517-526.
    • (2005) Clin Neurophysiol , vol.116 , pp. 517-526
    • Esteller, R.1    Echauz, J.2    D'Alessandro, M.3
  • 12
    • 34047116441 scopus 로고    scopus 로고
    • Human and automated detection of high-frequency oscillations in clinical intracranial EEG recordings
    • Gardner A.B., Worrell G.A., Marsh E., Dlugos D., Litt B. Human and automated detection of high-frequency oscillations in clinical intracranial EEG recordings. Clin Neurophysiol 2007, 118:1134-1143.
    • (2007) Clin Neurophysiol , vol.118 , pp. 1134-1143
    • Gardner, A.B.1    Worrell, G.A.2    Marsh, E.3    Dlugos, D.4    Litt, B.5
  • 13
    • 0038398958 scopus 로고    scopus 로고
    • Wavelet based automatic seizure detection in intracerebral electroencephalogram
    • Khan Y.U., Gotman J. Wavelet based automatic seizure detection in intracerebral electroencephalogram. Clin Neurophysiol 2003, 114:898-908.
    • (2003) Clin Neurophysiol , vol.114 , pp. 898-908
    • Khan, Y.U.1    Gotman, J.2
  • 14
    • 24644496662 scopus 로고    scopus 로고
    • An automatic warning system for epileptic seizures recorded on intracerebral EEGs
    • Grewal S., Gotman J. An automatic warning system for epileptic seizures recorded on intracerebral EEGs. Clin Neurophysiol 2005, 116:2460-2472.
    • (2005) Clin Neurophysiol , vol.116 , pp. 2460-2472
    • Grewal, S.1    Gotman, J.2
  • 15
    • 12344300348 scopus 로고    scopus 로고
    • A system to detect the onset of epileptic seizures in scalp EEG
    • Saab M.E., Gotman J. A system to detect the onset of epileptic seizures in scalp EEG. Clin Neurophysiol 2005, 116:427-442.
    • (2005) Clin Neurophysiol , vol.116 , pp. 427-442
    • Saab, M.E.1    Gotman, J.2
  • 16
    • 26944479675 scopus 로고    scopus 로고
    • Automatic seizure detection in EEG using logistic regression and artificial neural network
    • Alkan A., Koklukaya E., Subasi A. Automatic seizure detection in EEG using logistic regression and artificial neural network. J Neurosci Methods 2005, 148:167-176.
    • (2005) J Neurosci Methods , vol.148 , pp. 167-176
    • Alkan, A.1    Koklukaya, E.2    Subasi, A.3
  • 17
    • 24644444651 scopus 로고    scopus 로고
    • Detecting temporal lobe seizures from scalp EEG recordings: a comparison of various features
    • Van Putten M.J., Kind T., Visser F., Lagerburg V. Detecting temporal lobe seizures from scalp EEG recordings: a comparison of various features. Clin Neurophysiol 2005, 116:2480-2489.
    • (2005) Clin Neurophysiol , vol.116 , pp. 2480-2489
    • Van Putten, M.J.1    Kind, T.2    Visser, F.3    Lagerburg, V.4
  • 18
    • 22844431998 scopus 로고    scopus 로고
    • A neural network method for automatic and incremental learning applied to patient-dependent seizure detection
    • Wilson S.B. A neural network method for automatic and incremental learning applied to patient-dependent seizure detection. Clin Neurophysiol 2005, 116:1785-1795.
    • (2005) Clin Neurophysiol , vol.116 , pp. 1785-1795
    • Wilson, S.B.1
  • 19
    • 33744758949 scopus 로고    scopus 로고
    • Algorithm architectures for patient dependent seizure detection
    • Wilson S.B. Algorithm architectures for patient dependent seizure detection. Clin Neurophysiol 2006, 117:1204-1216.
    • (2006) Clin Neurophysiol , vol.117 , pp. 1204-1216
    • Wilson, S.B.1
  • 20
    • 34248567678 scopus 로고    scopus 로고
    • Approximate entropy-based epileptic EEG detection using artificial neural networks
    • Srinivasan V., Eswaran C., Sriraam N. Approximate entropy-based epileptic EEG detection using artificial neural networks. IEEE Trans Inf Technol Biomed 2007, 11:288-295.
    • (2007) IEEE Trans Inf Technol Biomed , vol.11 , pp. 288-295
    • Srinivasan, V.1    Eswaran, C.2    Sriraam, N.3
  • 21
    • 56349116249 scopus 로고    scopus 로고
    • Automated seizure onset detection for accurate onset time determination in intracranial EEG
    • Chan A.M., Sun F.T., Boto E.H., Wingeier B.M. Automated seizure onset detection for accurate onset time determination in intracranial EEG. Clin Neurophysiol 2008, 119:2687-2696.
    • (2008) Clin Neurophysiol , vol.119 , pp. 2687-2696
    • Chan, A.M.1    Sun, F.T.2    Boto, E.H.3    Wingeier, B.M.4
  • 22
    • 69549116488 scopus 로고    scopus 로고
    • A fuzzy rule-based system for epileptic seizure detection in intracranial EEG
    • Aarabi A., Fazel-Rezai R., Aghakhani Y. A fuzzy rule-based system for epileptic seizure detection in intracranial EEG. Clin Neurophysiol 2009, 120:1648-1657.
    • (2009) Clin Neurophysiol , vol.120 , pp. 1648-1657
    • Aarabi, A.1    Fazel-Rezai, R.2    Aghakhani, Y.3
  • 23
    • 74249108201 scopus 로고    scopus 로고
    • Seizure detection: an assessment of time- and frequency-based features in a unified two-dimensional decisional space using nonlinear decision functions
    • Tito M., Cabrerizo M., Ayala M., Jayakar P., Adjouadi M. Seizure detection: an assessment of time- and frequency-based features in a unified two-dimensional decisional space using nonlinear decision functions. J Clin Neurophysiol 2009, 26:381-391.
    • (2009) J Clin Neurophysiol , vol.26 , pp. 381-391
    • Tito, M.1    Cabrerizo, M.2    Ayala, M.3    Jayakar, P.4    Adjouadi, M.5
  • 24
  • 27
    • 34547573516 scopus 로고    scopus 로고
    • Mixed-band wavelet-chaos-neural network methodology for epilepsy and epileptic seizure detection
    • Ghosh-Dastidar S., Adeli H., Dadmehr N. Mixed-band wavelet-chaos-neural network methodology for epilepsy and epileptic seizure detection. IEEE Trans Biomed Eng 2007, 54:1545-1551.
    • (2007) IEEE Trans Biomed Eng , vol.54 , pp. 1545-1551
    • Ghosh-Dastidar, S.1    Adeli, H.2    Dadmehr, N.3
  • 28
    • 38349123053 scopus 로고    scopus 로고
    • Principal component analysis-enhanced cosine radial basis function neural network for robust epilepsy and seizure detection
    • Ghosh-Dastidar S., Adeli H., Dadmehr N. Principal component analysis-enhanced cosine radial basis function neural network for robust epilepsy and seizure detection. IEEE Trans Biomed Eng 2008, 55:512-518.
    • (2008) IEEE Trans Biomed Eng , vol.55 , pp. 512-518
    • Ghosh-Dastidar, S.1    Adeli, H.2    Dadmehr, N.3
  • 29
    • 44649182792 scopus 로고    scopus 로고
    • Detecting epileptic seizures in long-term human EEG: a new approach to automatic online and real-time detection and classification of polymorphic seizure patterns
    • Meier R., Dittrich H., Schulze-Bonhage A., Aertsen A. Detecting epileptic seizures in long-term human EEG: a new approach to automatic online and real-time detection and classification of polymorphic seizure patterns. J Clin Neurophysiol 2008, 25:119-131.
    • (2008) J Clin Neurophysiol , vol.25 , pp. 119-131
    • Meier, R.1    Dittrich, H.2    Schulze-Bonhage, A.3    Aertsen, A.4
  • 30
    • 77956064562 scopus 로고    scopus 로고
    • Seizure detection in temporal lobe epileptic EEGs using the best basis wavelet functions
    • Abibullaev B., Kim M.S., Seo H.D. Seizure detection in temporal lobe epileptic EEGs using the best basis wavelet functions. J Med Syst 2010, 34:755-765.
    • (2010) J Med Syst , vol.34 , pp. 755-765
    • Abibullaev, B.1    Kim, M.S.2    Seo, H.D.3
  • 31
    • 77955054723 scopus 로고    scopus 로고
    • Automatic epileptic seizure detection in EEGs based on line length feature and artificial neural networks
    • Guo L., Rivero D., Dorado J., Rabuñal J.R., Pazos A. Automatic epileptic seizure detection in EEGs based on line length feature and artificial neural networks. J Neurosci Methods 2010, 191:101-109.
    • (2010) J Neurosci Methods , vol.191 , pp. 101-109
    • Guo, L.1    Rivero, D.2    Dorado, J.3    Rabuñal, J.R.4    Pazos, A.5
  • 32
    • 77957685691 scopus 로고    scopus 로고
    • Epileptic seizure detection using multiwavelet transform based approximate entropy and artificial neural networks
    • Guo L., Rivero D., Pazos A. Epileptic seizure detection using multiwavelet transform based approximate entropy and artificial neural networks. J Neurosci Methods 2010, 193:156-163.
    • (2010) J Neurosci Methods , vol.193 , pp. 156-163
    • Guo, L.1    Rivero, D.2    Pazos, A.3
  • 33
    • 68149126079 scopus 로고    scopus 로고
    • Non-invasive computerized system for automatically initiating vagus nerve stimulation following patient-specific detection of seizures or epileptiform discharges
    • Shoeb A., Pang T., Guttag J., Schachter S. Non-invasive computerized system for automatically initiating vagus nerve stimulation following patient-specific detection of seizures or epileptiform discharges. Int J Neural Syst 2009, 19:157-172.
    • (2009) Int J Neural Syst , vol.19 , pp. 157-172
    • Shoeb, A.1    Pang, T.2    Guttag, J.3    Schachter, S.4
  • 34
    • 84984535836 scopus 로고    scopus 로고
    • Comparison of seizure detection algorithms in continuously monitored pediatric patients
    • Lee H.C., van Drongelen W., McGee A.B., Frim D.M., Kohrman M.H. Comparison of seizure detection algorithms in continuously monitored pediatric patients. J Clin Neurophysiol 2007, 24:137-146.
    • (2007) J Clin Neurophysiol , vol.24 , pp. 137-146
    • Lee, H.C.1    van Drongelen, W.2    McGee, A.B.3    Frim, D.M.4    Kohrman, M.H.5
  • 35
    • 0002196122 scopus 로고
    • On optimum methods in quickest detection problems
    • Shiryaev A.N. On optimum methods in quickest detection problems. Theory Probab Appl 1963, 8:22-46.
    • (1963) Theory Probab Appl , vol.8 , pp. 22-46
    • Shiryaev, A.N.1
  • 37
    • 83455225113 scopus 로고    scopus 로고
    • Quickest detection of state-transition in point processes: application to neuronal activity
    • A 29_#2013;S 2
    • Sarma S.V., Santaniello S. Quickest detection of state-transition in point processes: application to neuronal activity. Proceedings, 18th IFAC World Conference; Milan, Italy August 29-September 2 2011, 18:10021-10026.
    • (2011) Proceedings, 18th IFAC World Conference; Milan, Italy , vol.18 , pp. 10021-10026
    • Sarma, S.V.1    Santaniello, S.2
  • 38
  • 39
    • 80051766852 scopus 로고    scopus 로고
    • Graph-theoretical analysis reveals disrupted small-world organization of cortical thickness correlation networks in temporal lobe epilepsy
    • Bernhardt B.C., Chen Z., He Y., Evans A.C., Bernasconi N. Graph-theoretical analysis reveals disrupted small-world organization of cortical thickness correlation networks in temporal lobe epilepsy. Cereb Cortex 2011, 21:2147-2157.
    • (2011) Cereb Cortex , vol.21 , pp. 2147-2157
    • Bernhardt, B.C.1    Chen, Z.2    He, Y.3    Evans, A.C.4    Bernasconi, N.5
  • 40
    • 41349094118 scopus 로고    scopus 로고
    • Detection and characterization of changes of the correlation structure in multivariate time series
    • Müller M., Baier G., Galka A., Stephani U., Muhle H. Detection and characterization of changes of the correlation structure in multivariate time series. Phys Rev E 2005, 71:046116.
    • (2005) Phys Rev E , vol.71 , pp. 046116
    • Müller, M.1    Baier, G.2    Galka, A.3    Stephani, U.4    Muhle, H.5
  • 41
    • 34548484317 scopus 로고    scopus 로고
    • The influence of static correlations on multivariate correlation analysis of the EEG
    • Rummel C., Baier G., Müller M. The influence of static correlations on multivariate correlation analysis of the EEG. J Neurosci Methods 2007, 166:138-157.
    • (2007) J Neurosci Methods , vol.166 , pp. 138-157
    • Rummel, C.1    Baier, G.2    Müller, M.3
  • 43
    • 79961068110 scopus 로고    scopus 로고
    • Uniform approach to linear and nonlinear interrelation patterns in multivariate time series
    • Rummel C., Abela E., Müller M., et al. Uniform approach to linear and nonlinear interrelation patterns in multivariate time series. Phys Rev E 2011, 83:066215.
    • (2011) Phys Rev E , vol.83 , pp. 066215
    • Rummel, C.1    Abela, E.2    Müller, M.3
  • 44
    • 33845907132 scopus 로고    scopus 로고
    • Assessing seizure dynamics by analyzing the correlation structure of multichannel intracranial EEG
    • Schindler K.A., Leung H., Elger C.E., Lehnertz K. Assessing seizure dynamics by analyzing the correlation structure of multichannel intracranial EEG. Brain 2007, 130:65-77.
    • (2007) Brain , vol.130 , pp. 65-77
    • Schindler, K.A.1    Leung, H.2    Elger, C.E.3    Lehnertz, K.4
  • 45
    • 54749087960 scopus 로고    scopus 로고
    • Evolving functional network properties and synchronizability during human epileptic seizures
    • Schindler K.A., Bialonski S., Horstmann M.T., Elger C.E., Lehnertz K. Evolving functional network properties and synchronizability during human epileptic seizures. Chaos 2008, 18:033119.
    • (2008) Chaos , vol.18 , pp. 033119
    • Schindler, K.A.1    Bialonski, S.2    Horstmann, M.T.3    Elger, C.E.4    Lehnertz, K.5
  • 46
    • 77950516575 scopus 로고    scopus 로고
    • Peri-ictal correlation dynamics of high-frequency (80-200 Hz) intracranial EEG
    • Schindler K.A., Amor F., Gast H., et al. Peri-ictal correlation dynamics of high-frequency (80-200 Hz) intracranial EEG. Epilepsy Res 2010, 89:72-81.
    • (2010) Epilepsy Res , vol.89 , pp. 72-81
    • Schindler, K.A.1    Amor, F.2    Gast, H.3
  • 47
    • 78651293981 scopus 로고    scopus 로고
    • Graph analysis of epileptogenic networks in human partial epilepsy
    • Wilke C., Worrell G., He B. Graph analysis of epileptogenic networks in human partial epilepsy. Epilepsia 2011, 52:84-93.
    • (2011) Epilepsia , vol.52 , pp. 84-93
    • Wilke, C.1    Worrell, G.2    He, B.3
  • 48
    • 42749087848 scopus 로고    scopus 로고
    • Emergent network topology at seizure onset in humans
    • Kramer M.A., Kolaczyk E.D., Kirsh H.E. Emergent network topology at seizure onset in humans. Epilepsy Res 2008, 79:173-186.
    • (2008) Epilepsy Res , vol.79 , pp. 173-186
    • Kramer, M.A.1    Kolaczyk, E.D.2    Kirsh, H.E.3
  • 51
    • 1242343781 scopus 로고    scopus 로고
    • Dynamical resetting of the human brain at epileptic seizures: application of nonlinear dynamics and global optimization techniques
    • Iasemidis L.D., Shiau D.-S., Sackellares J.C., Pardalos P.M., Prasad A. Dynamical resetting of the human brain at epileptic seizures: application of nonlinear dynamics and global optimization techniques. IEEE Trans Biomed Eng 2004, 51:493-506.
    • (2004) IEEE Trans Biomed Eng , vol.51 , pp. 493-506
    • Iasemidis, L.D.1    Shiau, D.-S.2    Sackellares, J.C.3    Pardalos, P.M.4    Prasad, A.5
  • 52
    • 40449117426 scopus 로고    scopus 로고
    • Quantitative complexity analysis in multi-channel intracranial EEG recordings form epilepsy brains
    • Liu C.C., Pardalos P.M., Chaovalitwongse W.A., et al. Quantitative complexity analysis in multi-channel intracranial EEG recordings form epilepsy brains. J Comb Optim 2008, 15:276-286.
    • (2008) J Comb Optim , vol.15 , pp. 276-286
    • Liu, C.C.1    Pardalos, P.M.2    Chaovalitwongse, W.A.3
  • 57
    • 0016355478 scopus 로고
    • A new look at the statistical model identification
    • Akaike H. A new look at the statistical model identification. IEEE Trans Autom Control 1974, 19:716-723.
    • (1974) IEEE Trans Autom Control , vol.19 , pp. 716-723
    • Akaike, H.1
  • 60
    • 0344740780 scopus 로고    scopus 로고
    • Linear and nonlinear measures and seizure anticipation in temporal lobe epilepsy
    • Li D., Zhou W., Drury I., Savit R. Linear and nonlinear measures and seizure anticipation in temporal lobe epilepsy. J Comput Neurosci 2003, 15:335-345.
    • (2003) J Comput Neurosci , vol.15 , pp. 335-345
    • Li, D.1    Zhou, W.2    Drury, I.3    Savit, R.4
  • 61
    • 55349085144 scopus 로고    scopus 로고
    • Circadian rhythms, diet, and neuronal excitability
    • Allen C.N. Circadian rhythms, diet, and neuronal excitability. Epilepsia 2008, 49(Suppl. 8):124-126.
    • (2008) Epilepsia , vol.49 , Issue.SUPPL. 8 , pp. 124-126
    • Allen, C.N.1
  • 62
    • 77249164196 scopus 로고    scopus 로고
    • Stochastic transitions between neural states in taste processing and decision-making
    • Miller P., Katz D.B. Stochastic transitions between neural states in taste processing and decision-making. J Neurosci 2010, 30:2559-2570.
    • (2010) J Neurosci , vol.30 , pp. 2559-2570
    • Miller, P.1    Katz, D.B.2
  • 63
    • 57149085744 scopus 로고    scopus 로고
    • Detecting neural-state transitions using hidden Markov models for motor cortical prostheses
    • Kemere C., Santhanam G., Yu B.M., et al. Detecting neural-state transitions using hidden Markov models for motor cortical prostheses. J Neurophysiol 2008, 100:2441-2452.
    • (2008) J Neurophysiol , vol.100 , pp. 2441-2452
    • Kemere, C.1    Santhanam, G.2    Yu, B.M.3
  • 64
    • 77956000641 scopus 로고    scopus 로고
    • A computationally efficient method for nonparametric modeling neural spiking activity with point processes
    • Coleman T.P., Sarma S.V. A computationally efficient method for nonparametric modeling neural spiking activity with point processes. Neural Comp 2010, 22:2002-2030.
    • (2010) Neural Comp , vol.22 , pp. 2002-2030
    • Coleman, T.P.1    Sarma, S.V.2
  • 65
    • 77952562741 scopus 로고    scopus 로고
    • Using point process models to compare neuronal activity in subthalamic nucleus of Parkinson's patients and a healthy primate
    • Sarma S.V., Eden U.T., Cheng M.L., Williams Z.M., Hu R., Eskandar E.N., Brown E.N. Using point process models to compare neuronal activity in subthalamic nucleus of Parkinson's patients and a healthy primate. IEEE Trans Biomed Eng 2010, 57:1297-1305.
    • (2010) IEEE Trans Biomed Eng , vol.57 , pp. 1297-1305
    • Sarma, S.V.1    Eden, U.T.2    Cheng, M.L.3    Williams, Z.M.4    Hu, R.5    Eskandar, E.N.6    Brown, E.N.7


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.