protected void printTopKChild4Stn(String filePrefix, int topK) {
		String topKChild4StnFile = filePrefix + "topChild4Stn.txt";

		try {
			PrintWriter pw = new PrintWriter(new File(topKChild4StnFile));

			for (_Doc d : m_trainSet) {
				if (d instanceof _ParentDoc4DCM) {
					_ParentDoc4DCM pDoc = (_ParentDoc4DCM) d;

					pw.println(pDoc.getName() + "\t" + pDoc.getSenetenceSize());
					for (_Stn stnObj : pDoc.getSentences()) {
						HashMap<String, Double> likelihoodMap = rankChild4StnByLikelihood(
								stnObj, pDoc);

						int i = 0;
						pw.print((stnObj.getIndex() + 1) + "\t");

						for (String e : likelihoodMap.keySet()) {
							pw.print(e);
							pw.print(":" + likelihoodMap.get(e));
							pw.print("\t");

							i++;
						}
						pw.println();
					}
				}
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
	}