No such thing.
Variable Valve Timing (V.V.T.) - is any mechanism or method that can alter the shape or timing of a valve lift event within an internal combustion engine.
Direct Injection - where fuel is injected directly into the (main) cylinders of an engine, esp' in diesels or very rarely in petrol engines.
Variable direct injection system i believe .
Variable cam timing , direct fuel injection , coil over plug ignition,
sidi means Spark Ignition Direct Injection
both are same technologies ...CRDI is Common rail DIRECT INJECTION
variable timing injection
Gasoline Direct Injection
B. Direct materials, direct labor, and variable manufacturing overhead.
VDI is usually used in diesel engines. It stands for variable direct injection system and allows the amount of fuel to vary according to how hard the engine is working.
Turbo Direct Injection. Usually on diesel powered vehicles.
Direct labor is variable cost as it varies with the change in level of production of units.
If a variable X is in inverse variation with a variable Y, then it is in direct variation with the variable (1/Y).
DDIS means Direct Diesel Injection system which are used in diesel engines. It's similar to VVT (variable Valve timing) which are used in petrol engines.