How to create instance with type parameter through scala reflection?

Here is my code

package a1

trait Algorithm[T] {
  def someMethod(a: Int): T
}

package b2

import a1.Algorithm

class Word2Vec[T] extends Algorithm[T] {
  def someMethod(a: Int): T = a.asInstanceOf[T]
}

package c3

import a1.Algorithm

object Main {
  def main(args:Array[String]) = {
    val word2vec:Algorithm[Float] = Class.forName("b2.Word2Vec").newInstance().asInstanceOf[Algorithm[Float]]
    val a = word2vec.someMethod(123)
    println(a)
  }
}

and I got this:

Exception in thread "main" java.lang.ClassCastException: java.lang.Integer cannot be cast to java.lang.Float
    at scala.runtime.BoxesRunTime.unboxToFloat(BoxesRunTime.java:107)
    at c3.Main$.main(Main.scala:8)
    at c3.Main.main(Main.scala)

by the way,How could I get a type when I get a string name. I have an "int" and I want to pass type Int as the type parameter for generic