You are working with a dataset that is too large to process on a single machine. You decide to simulate a parallel data processing environment using Python's multiprocessing library. Requirements: Write a Python script that simulates the partitioning of data and its parallel processing. The script should divide a large array of numbers into smaller chunks, distribute these chunks across multiple processes for summing the numbers, and then aggregate the results. Discuss how this simulation relates to the concepts of Shared Memory and Message Passing.

Assignment as a compressed archive $(.$zip$)$ containing all your source code, reports, and documentation. Each sub task should be clearly labeled and contain its own README file with instructions on running the code and understanding the output