Install Nginx Passenger Rails on Ubuntu [Failed]

nginx.conf

http {
    passenger_root /home/poc/.rvm/gems/ruby-1.9.3-p448/gems/passenger-4.0.10;
    passenger_ruby /home/poc/.rvm/wrappers/ruby-1.9.3-p448/ruby;

    include       mime.types;
    default_type  application/octet-stream;

    #log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
    #                  '$status $body_bytes_sent "$http_referer" '
    #                  '"$http_user_agent" "$http_x_forwarded_for"';

    #access_log  logs/access.log  main;

    sendfile        on;
    #tcp_nopush     on;

    #keepalive_timeout  0;
    keepalive_timeout  65;

    #gzip  on;

    server {
        listen       80;
        server_name  localhost;
        root   /home/poc/Dropbox/Ruby/rspec_sandbox/public;
        passenger_enabled on;

        #charset koi8-r;

        #access_log  logs/host.access.log  main;

        location / {
            root   /home/poc/Dropbox/Ruby/rspec_sandbox/public;
            passenger_enabled on;
            index  index.html index.htm;
        }

...

Rails App Environment

Project Path : /home/poc/Dropbox/Ruby/zeus

poc@ubuntu:zeus$ which ruby
/home/poc/.rvm/rubies/ruby-1.9.3-p448/bin/ruby

poc@ubuntu:zeus$ gem list

*** LOCAL GEMS ***

actionmailer (4.0.0, 3.2.12)
actionpack (4.0.0, 3.2.12)
activemodel (4.0.0, 3.2.12)
activerecord (4.0.0, 3.2.12)
activerecord-deprecated_finders (1.0.3)
activeresource (3.2.12)
activesupport (4.0.0, 3.2.12)
arel (4.0.0, 3.0.2)
atomic (1.1.10)
bootstrap-sass (2.3.2.0, 2.1.0.0)
builder (3.1.4, 3.0.4)
bundler (1.3.5)
bundler-unload (1.0.1)
celluloid (0.12.4)
coffee-rails (4.0.0, 3.2.2)
coffee-script (2.2.0)
coffee-script-source (1.6.3, 1.4.0)
connection_pool (1.0.0)
daemon_controller (1.1.4)
diff-lcs (1.2.4)
erubis (2.7.0)
execjs (1.4.0)
facter (1.6.17)
hike (1.2.3, 1.2.1)
hirb (0.7.1)
hirb-unicode (0.0.5)
i18n (0.6.4, 0.6.1)
jbuilder (1.4.2)
journey (1.0.4)
jquery-rails (3.0.4, 2.2.1)
json (1.8.0, 1.7.7)
mail (2.5.4, 2.4.4)
metaclass (0.0.1)
mime-types (1.23, 1.21)
mini_portile (0.5.1)
minitest (4.7.5)
mocha (0.14.0)
multi_json (1.7.7, 1.6.1)
nokogiri (1.6.0)
passenger (4.0.10)
polyglot (0.3.3)
rack (1.5.2, 1.4.5)
rack-cache (1.2)
rack-ssl (1.3.3)
rack-test (0.6.2)
rails (4.0.0, 3.2.12)
railties (4.0.0, 3.2.12)
rake (10.1.0, 10.0.3)
rdoc (3.12.2, 3.12.1)
redis (3.0.2)
redis-namespace (1.2.1)
rspec (2.14.1)
rspec-core (2.14.4)
rspec-expectations (2.14.0)
rspec-mocks (2.14.1)
rspec-rails (2.14.0)
rubygems-bundler (1.2.2)
rvm (1.11.3.8)
sass (3.2.9, 3.2.5)
sass-rails (4.0.0, 3.2.6)
sdoc (0.3.20)
sidekiq (2.7.4)
sprockets (2.10.0, 2.2.2)
sprockets-rails (2.0.0)
sqlite3 (1.3.7)
thor (0.18.1, 0.17.0)
thread_safe (0.1.0)
tilt (1.4.1, 1.3.3)
timers (1.1.0)
treetop (1.4.14, 1.4.12)
turbolinks (1.3.0)
tzinfo (0.3.37, 0.3.35)
uglifier (2.1.2, 1.3.0)
unicode-display_width (0.1.1)

steps

I follow the steps in the link , but not worked
https://www.digitalocean.com/community/articles/how-to-install-rails-and-nginx-with-passenger-on-ubuntu

The Failed message is passenger send "Internal server error"  "An error occurred while starting up the preloader: it did not write a handshake message in time."

you can check the detail log by picture
https://dl.dropboxusercontent.com/u/23461380/QQ%E6%88%AA%E5%9C%961020724161628.png