How to Set the Particle Generation Location

public classParticleSystem{
private Part [ ] mParticles;
// Number of particles
private int PARTICLECOUNT = 15;

// for use to draw the part
private FloatBuffer mVertexBuffer;
private ShortBuffermIndexBuffer;

publicParticleSystem(){
    mParticles = new Part [PARTICLECOUNT];

    // setup the random number generator
    Random gen = new Random (System.currentTimeMillis());
    // loop through all the parts and create new instances of each one
    for (inti=0;i<PARTICLECOUNT;i++) {
        mParticles[i] = new Part(gen.nextFloat(), gen.nextFloat(), gen.nextFloat());
    }

    // Determine triangle size
    // as simple triangle, Kinda like this^
    float[] codes = {
            - 0.4f, 0.0f, 0.0f, // Left
            0.4f, 0.0f, 0.0f, // Right
            0.0f, 0.0f, 0.4f}; // Above
    short [ ] = {0,1,2};

    mVertexBuffer = makeFloatBuffer (coords);
    mIndexBuffer=makeShortBuffer(iCords);
}

// used to make native order float buffers
private FloatBuffer makeFloatBuffer(float[]arr){
    ByteBuffer bb = ByteBuffer.allocateDirect(arr.length*4);
    bb.order(ByteOrder.nativeOrder());
    FloatBuffer fb = bb.asFloatBuffer();
    fb.put(arr);
    fb.position(0);
    return fb;
}

// used to make native order short buffers
private ShortBuffer makeShortBuffer(short[]arr){
    ByteBuffer bb = ByteBuffer.allocateDirect(arr.length*4);
    bb.order(ByteOrder.nativeOrder());
    ShortBufferib=bb.asShortBuffer();
    ib.put(arr);
    ib.position(0);
    returnib;
}

public void draw (GL10gl) {
    // Define vertex array.Three is three dimensions.
    gl.glVertexPointer(3,GL10.GL_FLOAT, 0, mVertexBuffer);
    // Specifying the color of the particle.It's not the background.
    gl.glColor4f(1f, 1f, 1f, 1f);
    for (inti=0;i<PARTICLECOUNT;i++) {
        gl.glPushMatrix();
        gl.glTranslatef(mParticles[i].x, mParticles[i].y, mParticles[i].z);
        // GL_TRIANGLES triangle??
        gl.glDrawElements (GL10.GL_TRIANGLES, 3,GL10.GL_UNSIGNED_SHORT, mIndexBuffer);
        gl.glPopMatrix();
    }
}

// Simply have the parts fall at a hard coded gravity rate
// and when they hit zero, bump the back up to a z of 1.0f
public void update() {
    for (inti=0;i<PARTICLECOUNT;i++) {
        mParticles[i].z=mParticles[i].z-0.01f;// Drop Speed
        if(mParticles[i].z<-6.0f) {// drop position.lower rank
            mParticles[i].z=1.5f;// First position of the drop
        }
    }
}