**Subdepartment
of Real-Time CAD Systems**

Institution
of Russian Academy of Sciences

Dorodnicyn Computing Centre of RAS

**works at the next problems:**

1. Elaboration of Real-Time-Systems CAD;

2. Algorithms of work planning in multiprocessor systems;

3. Estimation of initial gas reserves and transfers in gas deposit.

__1____. ____Elaboration
of Real-Time-Systems CAD - RTS-CONSTRUCTOR__

RTS-CONSTRUCTOR
is used for computer aided design and generation of real-time systems,
fulfiling data processing of periodically entering from outside input data in
the tempo of data entering, with time restrictions. With the help of RTS-CONST-RUCTOR
the user can quickly build his own real-time system of application modules.

*RTS-CONSTRUCTOR
is nessessary everywhere the real-time systems are applied:*

automation of experimental investigations;

control of complicated technical systems;

medicine - permanent control of patient’s state;

ecological monitoring;

scientific forecasting and passing of intellectual
decisions.

*Generation
of real-time system*

To
generate his own real-time system a user must provide application modules ( C,
FORTRAN, PASCAL and Assembler are allowed) and task for data processing in real
time mode (RT-program).

*All
other job will be done by our RTS-CONSTRUCTOR!*

It will
successfully deal with such problems as synchronization of modules and data
interchange, eliminating of deadlocks and optimization of application modules
passing.

So, our
RTS-CONSTRUCTOR supports all functions of system analyst and system programmer.

*Basic principles of source
language*

Input
data enter the computer periodically through I/O ports. These data form data
frames. The structure of the frame must be described by user in his RT-program.

Using special
constructions, named RT-loops, the user also defines tempoes of data processing
and results visialization to be produced by different application modules in
ratio to the period of data input. If these tempoes can be implemented,
RTS-CONSTRUCTOR garantees that all directive periods will not be disturbed. Otherwise
it prints a message that such data processing isn't possible to be produced on
the user's computer.

RTS-CONSTRUCTOR
differs from data stream systems, it permits to work with different data generations
simultaniously - the system reserves special buffers for them.

The
source launguage also gives an opportunity to react on input aperiodical
signals (useful in case of extraordinary situaton with controlled object) and
to fulfil application modules in background mode.

*Algorithmic support*

RTS-CONSTRUCTOR
uses the original method of sheduling, ensures fulfilment of application
modules in pre-defined derective periods. For this purpose the system builds
the mathematical model of data processing in form of data stream graph.

Original
algorithms also ensure optimal memory allocation during real-time session.

*Current situation and nearest future*

At
present time version 1.0 of RTS-CONSTRUCTOR for IBM-compatible computers with
MS DOS 3.30 and later is available for users. Application object modules must
satisfy the MICROSOFT object standart for large memory model.

RTS,
designed with RTS-CONSTRUCTOR, can recieve input information through ports COM1
and COM2, as well as through non-standard serial or parallel I/O ports.

In the
nearest future we complete the system with dialog shell which gives a user an
opportunity to write source task with menus only, avoiding source launguage.

**2****. Algorithms of work planning
in multiprocessor systems**

Preemptive
and nonpreemptive sheduling algorithms are elaborated for multiprocessor
systems when speeds of processors and release times, due data and processing
requirements are known. Next problems were researched:

1.
Demands to execute the jobs are entering periodically. A polynomial algorithm
of construction of feasible schedule was elaborated. The algorithm is based on
reduction this problem to network flow problem.

2.
Interruption and preemption expenditures are took into consideration. This problem
is *NP*-complete. For some particular cases algorithms were elaborated.

*NP*-complete. The algorithm is based on
reduction of initial problem to integer multiproduct network flow problem. This
algorithm finds a feasible schedule and minimizes the number of

interruptions
and preemptions.

**3****. Estimation of initial gas
reserves and transfers in gas deposit**

The
method of estimation of gas deposit parameters (gas reserves and transfer
coefficients) was eleborated. The method is based on use of gas deposit block model
elaborated by P.A. Geresh and on solving a material balance equations system.

As a
rule, in the case of a pressures difference in different parts of exploited
deposit is small a matrix of coefficients at undeterminate parameters of this
system is singular. Known methods of solving of material balance equations
systems are characterized by instability of results in relation to small
variation of initial data. Suggested method does not have this defect and
enables to estimate gas reserves and transfer coefficients at initial stage of
exploitation of deposit.

The
problem consists in finding the initial gas reserves in each block and transfer
coefficients given the pressures and qauntities of mined gas in each block. Elaborated
method is based on minimizing the deviation of average pressure in blocks and
pressure calculated by means of the model (direct comparison of parameters
measured). The numerical methods of solving this problem and different its
modifications were realized by system EXCEL and programming language C.
Elaborated programs were used for calculation of gas reserves and transfers in
Sovetabad, Shebelinsk and Yamburg gas deposits.

**Our address:**

**Moscow,
119333, GSP-1, Vavilova street, 40**

**Dr.
Meran G. Furugian, Dmitry R. Gonchar**

**E-mail:
rts@ccas.ru, rtsccas@ya.ru**

**Phone (499) 135-4029, fax 135-6159;**