diff --git a/NEWS b/NEWS
index ef890a572f3b260109ca5a908b3e03a785f3a5c5..05fc96a5413b1a350bbe6ed5fef8329e80121729 100755
--- a/NEWS
+++ b/NEWS
@@ -7,6 +7,12 @@ NEWS/ChangeLog for hydroPSO
                              AND (topology!="gbest" | method!="pso")
                           -) new 'random.update' parameter for the 'control' variable, in order to allow random update of personal/global best
                           -) default value of the inertia weight 'IW' was changed from (linearly decreasing) IW.w= c(1.2, 0.4) to 'IW.w=1/(2*log(2))'
+                          -) default value for the time-varying c1 was changed from (non-linearly decreasing) 'TVc1.rng= c(2.2, 1.8)' to 
+                             'TVc1.rng= c(1.28, 1.05)'. However, by default 'use.TVc1= FALSE' still.
+                          -) default value for the time-varying c2 was changed from (non-linearly increasing) 'TVc1.rng= c(1.8, 2.2)' to 
+                             'TVc2.rng= c(1.05, 1.28)'. However, by default 'use.TVc2= FALSE' still.
+                          -) default value for the time-varying lambda was changed from (non-linearly decreasing) 'TVlambda.rng= c(0.9, 0.1)' to 
+                             'TVlambda.rng= c(1, 0.25)'. However, by default 'use.TVlambda= FALSE'
                           -) source code was tidy up
                              
 0.1-56	14-Jun-2012
diff --git a/R/PSO_v2012.R b/R/PSO_v2012.R
index 94182f031ae602ab9fb23a9abeb0b24e2e55e6e9..48b575c901980c756b384fcbfd00fdbde9933ace 100755
--- a/R/PSO_v2012.R
+++ b/R/PSO_v2012.R
@@ -1392,9 +1392,9 @@ hydroPSO <- function(
 	    topology=c("random", "gbest", "lbest", "vonNeumann"), K=3, iter.ini=0, ngbest=4, # only used when 'method=ipso'   
 
 	    use.IW = TRUE, IW.type=c("linear", "non-linear", "runif", "aiwf", "GLratio"), IW.w=1/(2*log(2)), IW.exp= 1, 
-	    use.TVc1= FALSE, TVc1.type=c("non-linear", "linear", "GLratio"), TVc1.rng= c(2.2, 1.8), TVc1.exp= 1.5, 
-	    use.TVc2= FALSE, TVc2.type=c("non-linear", "linear"), TVc2.rng= c(1.8, 2.2), TVc2.exp= 1.5, 
-	    use.TVlambda=FALSE, TVlambda.type=c("non-linear", "linear"), TVlambda.rng= c(0.9, .1), TVlambda.exp= 1.7, 
+	    use.TVc1= FALSE, TVc1.type=c("non-linear", "linear", "GLratio"), TVc1.rng= c(1.28, 1.05), TVc1.exp= 1.5, 
+	    use.TVc2= FALSE, TVc2.type=c("non-linear", "linear"), TVc2.rng= c(1.05, 1.28), TVc2.exp= 1.5, 
+	    use.TVlambda=FALSE, TVlambda.type=c("non-linear", "linear"), TVlambda.rng= c(1, 0.25), TVlambda.exp= 1.7, 
 	    use.RG = FALSE, RG.thr= 1.1e-4, RG.r= 0.8, RG.miniter= 5, # RG.r not used in reagrouping
 	    
 	    plot=FALSE,