NodeJS app can't find Sequelize if launched from the wrong path

If I go to mydir/core and enter

/usr/bin/node app.js &

my application starts fine. But if I go to mydir and enter

/usr/bin/node core/app.js &

I get errors.

    core/user/dbConfig.js:6
var sequelize = new Sequelize(config.connections.postgres.database, config.con
                                                ^
TypeError: Cannot read property 'postgres' of undefined
    at Object.<anonymous> (/home/dwil/code15/git_code/YB/root/services/core/user/dbConfig.js:6:49)
    at Module._compile (module.js:456:26)
    at Object.Module._extensions..js (module.js:474:10)
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:312:12)
    at Module.require (module.js:364:17)
    at require (module.js:380:17)
    at Object.<anonymous> (/home/dwil/code15/git_code/YB/root/services/core/app.js:12:10)
    at Module._compile (module.js:456:26)
    at Object.Module._extensions..js (module.js:474:10)

sudo npm install -g sequelize doesn't solve it.

How do I install / configure so that I can start from a different directory? This matters b/c I'm trying to start it via Monit. That's why "just change into the right directory" is not a viable answer. Thanks!