Ember component keyboard event does not trigger

Folloing the guide http://ift.tt/2iYZN0S. I try to bind event handler for key event for a component but seems it does not work. I do not see an alert when I press a key; however, the doubleClick event handler can be triggered.

What I want to achive is to use key 1 to select the first radio button.

Updated

The event can only be triggered when the radio button has the focus.

My Question

is there a way to bind the keyboard event with out make particular control in focus?

Code

Component JS,

import Ember from 'ember';

export default Ember.Component.extend({
    classNames: ['quiz-control'],

    keyUp(e) {
        alert(e.keyCode);
    },

    keyDown(e) {
        alert(e.keyCode);
    },

    keyPress(e) {
        alert(e.keyCode);
    }

});

Component HTML,

<input name="ans" type="radio" id="op0"/>
<label for="op0">1</label>

<input name="ans" type="radio" id="op1"/>
<label for="op1">2</label>

<input name="ans" type="radio" id="op2"/>
<label for="op2">3</label>

<input name="ans" type="radio" id="op3"/>
<label for="op3">4</label>