Certainly! Here's a detailed abstract and table of contents for project topics #84, #85, #86, #87, and #88.

**Project Topic #84: Design and implementation of a blockchain-based digital asset management system**
. Introduction
  - Background and significance of customer churn analysis
  - Objectives of the project
2. Literature Review
  - Overview of customer churn prediction models
  - State-of-the-art machine learning algorithms for predictive analysis
3. Data Collection and Preprocessing
  - Sources of customer data
  - Data preprocessing and feature engineering
4. Model Development and Training
  - Selection of machine learning algorithms
  - Model training and validation
5. Performance Evaluation
  - Evaluation metrics and criteria
  - Comparative analysis of predictive models