loading jquery plugins with require js

I am new to require js, and the problem is I don't really understand how to load jQuery plugins.

I would like to load multiple plugins but I already have problems with the first one, with the chose plugin

js

//site full url
var siteUrl = window.location.protocol+"//"+window.location.host + "/";

requirejs.config({
    baseUrl: siteUrl + "assets/js",

    paths: {
        "jquery": "libs/jquery",
        "jquery-ui": "libs/jquery-ui",
        "bootstrap": "libs/bootstrap",
        "scripts": "scripts",
        "plugins": "plugins",
    }, 
});

requirejs(['jquery', 'jquery-ui', 'bootstrap', 'plugins/chosen'],
function($, chosen){
    $('.chzn-select').chosen();
});

my test html

<select data-placeholder="Choose a country..." style="width:350px;" class="chzn-select">
    <option value="">Test</option>
    <option value="">Test</option>
    <option value="">Test</option>
</select>

and when I try to load it I get the following error

TypeError: $ is not a function


...tion(){"in"==self.hoverState&&self.show()},self.options.delay.show),void 0):self...

bootstrap.js (line 6)

TypeError: $(...).chosen is not a function


$('.chzn-select').chosen();

Could someone please point out what I am doing wrong?