diff --git a/src/main/hivemall/classifier/ConfidenceWeightedUDTF.java b/src/main/hivemall/classifier/ConfidenceWeightedUDTF.java
index 7b8e2894..846d13a8 100644
--- a/src/main/hivemall/classifier/ConfidenceWeightedUDTF.java
+++ b/src/main/hivemall/classifier/ConfidenceWeightedUDTF.java
@@ -67,8 +67,8 @@ protected boolean returnCovariance() {
     @Override
     protected Options getOptions() {
         Options opts = super.getOptions();
-        opts.addOption("phi", "confidence", true, "Confidence parameter [default 0.5]");
-        opts.addOption("eta", "hyper_c", true, "Confidence hyperparameter eta in range (0.5, 1] [default 0.7]");
+        opts.addOption("phi", "confidence", true, "Confidence parameter [default 1.0]");
+        opts.addOption("eta", "hyper_c", true, "Confidence hyperparameter eta in range (0.5, 1] [default 0.85]");
         return opts;
     }
 
@@ -76,7 +76,7 @@ protected Options getOptions() {
     protected CommandLine processOptions(ObjectInspector[] argOIs) throws UDFArgumentException {
         final CommandLine cl = super.processOptions(argOIs);
 
-        float phi = 0.5f;
+        float phi = 1.f;
         if(cl != null) {
             String phi_str = cl.getOptionValue("phi");
             if(phi_str == null) {
diff --git a/src/main/hivemall/classifier/SoftConfideceWeightedUDTF.java b/src/main/hivemall/classifier/SoftConfideceWeightedUDTF.java
index 00c4faa0..d22c7786 100644
--- a/src/main/hivemall/classifier/SoftConfideceWeightedUDTF.java
+++ b/src/main/hivemall/classifier/SoftConfideceWeightedUDTF.java
@@ -69,8 +69,8 @@ protected boolean returnCovariance() {
     @Override
     protected Options getOptions() {
         Options opts = super.getOptions();
-        opts.addOption("phi", "confidence", true, "Confidence parameter [default 0.5]");
-        opts.addOption("eta", "hyper_c", true, "Confidence hyperparameter eta in range (0.5, 1] [default 0.7]");
+        opts.addOption("phi", "confidence", true, "Confidence parameter [default 1.0]");
+        opts.addOption("eta", "hyper_c", true, "Confidence hyperparameter eta in range (0.5, 1] [default 0.85]");
         opts.addOption("c", "aggressiveness", true, "Aggressiveness parameter C [default 1.0]");
         return opts;
     }
@@ -79,7 +79,7 @@ protected Options getOptions() {
     protected CommandLine processOptions(ObjectInspector[] argOIs) throws UDFArgumentException {
         final CommandLine cl = super.processOptions(argOIs);
 
-        float phi = 0.5f;
+        float phi = 1.f;
         float c = 1.f;
         if(cl != null) {
             String phi_str = cl.getOptionValue("phi");
diff --git a/src/main/hivemall/classifier/multiclass/MulticlassConfidenceWeightedUDTF.java b/src/main/hivemall/classifier/multiclass/MulticlassConfidenceWeightedUDTF.java
index 4d0d038a..ecb6eb29 100644
--- a/src/main/hivemall/classifier/multiclass/MulticlassConfidenceWeightedUDTF.java
+++ b/src/main/hivemall/classifier/multiclass/MulticlassConfidenceWeightedUDTF.java
@@ -71,8 +71,8 @@ protected boolean returnCovariance() {
     @Override
     protected Options getOptions() {
         Options opts = super.getOptions();
-        opts.addOption("phi", "confidence", true, "Confidence parameter [default 0.5]");
-        opts.addOption("eta", "hyper_c", true, "Confidence hyperparameter eta in range (0.5, 1] [default 0.7]");
+        opts.addOption("phi", "confidence", true, "Confidence parameter [default 1.0]");
+        opts.addOption("eta", "hyper_c", true, "Confidence hyperparameter eta in range (0.5, 1] [default 0.85]");
         return opts;
     }
 
@@ -80,7 +80,7 @@ protected Options getOptions() {
     protected CommandLine processOptions(ObjectInspector[] argOIs) throws UDFArgumentException {
         final CommandLine cl = super.processOptions(argOIs);
 
-        float phi = 0.5f;
+        float phi = 1.f;
         if(cl != null) {
             String phi_str = cl.getOptionValue("phi");
             if(phi_str == null) {
diff --git a/src/main/hivemall/classifier/multiclass/MulticlassSoftConfidenceWeightedUDTF.java b/src/main/hivemall/classifier/multiclass/MulticlassSoftConfidenceWeightedUDTF.java
index de6011ee..e10d0175 100644
--- a/src/main/hivemall/classifier/multiclass/MulticlassSoftConfidenceWeightedUDTF.java
+++ b/src/main/hivemall/classifier/multiclass/MulticlassSoftConfidenceWeightedUDTF.java
@@ -70,8 +70,8 @@ protected boolean returnCovariance() {
     @Override
     protected Options getOptions() {
         Options opts = super.getOptions();
-        opts.addOption("phi", "confidence", true, "Confidence parameter [default 0.5]");
-        opts.addOption("eta", "hyper_c", true, "Confidence hyperparameter eta in range (0.5, 1] [default 0.7]");
+        opts.addOption("phi", "confidence", true, "Confidence parameter [default 1.0]");
+        opts.addOption("eta", "hyper_c", true, "Confidence hyperparameter eta in range (0.5, 1] [default 0.85]");
         opts.addOption("c", "aggressiveness", true, "Aggressiveness parameter C [default 1.0]");
         return opts;
     }
@@ -80,7 +80,7 @@ protected Options getOptions() {
     protected CommandLine processOptions(ObjectInspector[] argOIs) throws UDFArgumentException {
         final CommandLine cl = super.processOptions(argOIs);
 
-        float phi = 0.5f;
+        float phi = 1.f;
         float c = 1.f;
         if(cl != null) {
             String phi_str = cl.getOptionValue("phi");
diff --git a/src/main/hivemall/common/WeightValue.java b/src/main/hivemall/common/WeightValue.java
index 11accdb8..31708be9 100644
--- a/src/main/hivemall/common/WeightValue.java
+++ b/src/main/hivemall/common/WeightValue.java
@@ -61,7 +61,7 @@ public String toString() {
     }
 
     public static final class WeightValueWithCovar extends WeightValue {
-        public static float DEFAULT_COVAR = 1.f;
+        public static final float DEFAULT_COVAR = 1.f;
 
         final float covariance;
 
diff --git a/src/main/hivemall/ensemble/ArgminKLDistanceUDAF.java b/src/main/hivemall/ensemble/ArgminKLDistanceUDAF.java
index 1dd830d1..1a3effeb 100644
--- a/src/main/hivemall/ensemble/ArgminKLDistanceUDAF.java
+++ b/src/main/hivemall/ensemble/ArgminKLDistanceUDAF.java
@@ -5,7 +5,7 @@
 import org.apache.hadoop.hive.ql.exec.UDAFEvaluator;
 import org.apache.hadoop.io.FloatWritable;
 
-@Description(name = "argmin_kld", value = "_FUNC_(mean [, covar]) - Returns mean or covar that minimize a KL-distance among distributions", extended = "The returned value is (1.0 / (sum(1.0 / covar))) * (sum(mean / covar)")
+@Description(name = "argmin_kld", value = "_FUNC_([mean,] covar) - Returns mean or covar that minimize a KL-distance among distributions", extended = "The returned value is (1.0 / (sum(1.0 / covar))) * (sum(mean / covar)")
 public class ArgminKLDistanceUDAF extends UDAF {
 
     public static class ArgminMeanUDAFEvaluator implements UDAFEvaluator {
@@ -95,7 +95,7 @@ public boolean merge(FloatWritable o) {
         }
 
         public FloatWritable terminate() {
-            return empty ? null : new FloatWritable(sum_inv_covar);
+            return empty ? null : new FloatWritable(1.f / sum_inv_covar);
         }
     }
 
diff --git a/src/main/hivemall/utils/lang/NumberUtils.java b/src/main/hivemall/utils/lang/NumberUtils.java
index ac6cea7e..27885ba0 100644
--- a/src/main/hivemall/utils/lang/NumberUtils.java
+++ b/src/main/hivemall/utils/lang/NumberUtils.java
@@ -1,3 +1,23 @@
+/*
+ * Hivemall: Hive scalable Machine Learning Library
+ *
+ * Copyright (C) 2013-2014
+ *   National Institute of Advanced Industrial Science and Technology (AIST)
+ *   Registration Number: H25PRO-1520
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
 package hivemall.utils.lang;
 
 public final class NumberUtils {
diff --git a/target/hivemall.jar b/target/hivemall.jar
index 3bab9bd7..1f653c00 100644
Binary files a/target/hivemall.jar and b/target/hivemall.jar differ