def close(self):
		'''关闭与数据库的连接'''
		if VERBOSE:
			print 'Database connection CLOSE.'
		self.conn.close()
def permutation_subjects(y):
    """Permute class labels of Contextual Disorder dataset.
    """
    y_perm = np.random.randint(0, 2, len(y)/2)
    y_perm = np.concatenate((y_perm, np.logical_not(y_perm).astype(int)))
    return y_perm