The UK Professional standards Framework $($UKPSF$)$ aims to support the development of teaching and learning in higher education. A professional development organization is setting up a database to manage information and track the research, descriptors, learners, activities, knowledges and values.

The research has a unique research code, as well as title, description and year. Every research will have one descriptor and each descriptor may write more than one research. For each descriptor, we need to store the descriptor ID unique number, type, symbol, major, phone $($multiple values$),$ roles and dimensions evidences cover.

Information to be stored about each learners includes unique learner ID$,$ name, birthday, age $($derived from birthday$),$ email and phone. Each research can have one or more learners and each learner can participate in one or more research.

A descriptor could be teaching multiple students in the higher education and a learner is learned by one or more descriptor.

The UKPSF clearly outlines the dimensions of professional practice with higher education teaching and learning support as area of activities, core Knowledges and professional values. Each activity is described by an activity code, symbol, description question, description answer, examples, book evidence references and paper evidence references. The activity code is unique value for each Activity. Each knowledge has a unique Knowledge code, symbol, description question, description answer, examples, book evidence references and paper evidence references. A value is identified by the unique value code, symbol, description question, description answer, examples, book evidence references and paper evidence references. Each research has one or more activities, knowledges and values. Each activity, knowledges or value can belong to multiple researches.

Design an ER model for this database. Note any assumption that you may need to design your ER$.$