[comp.doc.techreports] tr-input/smu89

leff@smu.UUCP (Laurence Leff) (12/14/89)

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89-CSE-1.                                                             ($1.00)

            MODELING TRANSACTIONS IN OBJECT ORIENTED DATA BASES*
                  Francisco Mariategui and Margaret H. Eich
                                January 1989

     We present a  new model for  transactions  in Object Oriented Data Bases 
(OODB).   This  model  captures  the  shape  of transactions by following the 
behavior  of the  message passing  mechanism inherent  in the object oriented 
paradigm.  We call this new kind  of transaction, "The Pair <GM, DM>".   This 
dynamic model gives rise to tree structured transactions.  The end product of 
this structure  are data  base accesses.   Our model  builds a bridge between 
message  passing, by  which objects  communicate, and  data base accesses, by 
which transactions communicate.  Thereby closing the gap  between the dynamic 
view of the world (objects) and the static view of the world (data bases). 

*  This  material is based in part upon  work supported by the Texas Advanced 
   Research Program (Advanced Technology Program) under Grant No. 2265 and by 
   the National Science Foundation under Grant IRI-8713654. 
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89-CSE-2.                                                            ($1.25)

         DAA - A PROTOTYPE OF AN INTEGRATED PROTOTYPING SYSTEM (IPS)
                        Programmer's Reference Manual
                          W. P. Yin and M. M. Tanik

     This  document  describes  details  of  the implementation of the Design 
Activity  Agent  (DAA).   Topics  covered  are:   the  project  objectives, a 
description   of  built-in   maintenance  aids   in  the   program,  facility 
descriptions, a description of  Design Object Descriptive Attribute  Notation 
(DODAN),  a  list  of  unimplemented  features,  a  discussion  of  the rapid 
prototyping   environment   being   used,   and   possibilities   for  future 
modification.  The actual source code for the program is included separately.  
The program of DAA  is written in ART  (The Automatic Reasoning Tool)  a rule 
like  language, using forward chaining  mechanism.  Some portions are written 
in Common-lisp.   The DODAN description  program is written  in ART.  A large 
number of ART utilities are used in the program.  It is necessary to read the 
ART manuals, to fully understand the program.
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89-CSE-3.                                                           ($3.50)

         DAA - A PROTOTYPE OF AN INTEGRATED PROTOTYPING SYSTEM (IPS)
                                User's Manual
                          W. P. Yin and M. M. Tanik

     This system implements a  prototype of a software design paradigm on top 
of  the  ART.  The system is primarily meant to  be used as a software design 
environment for aiding a software  designer to design software programs,  but 
can also be used as an intelligent assistance to understand software designs.  
DAA allows  a user  to construct  a software  design in  DODAN by using ZMACS 
editor, save the design in a file, review and analyze the design.
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89-CSE-4.                                                            ($1.00)

 THE AT&T VIDEOTEX COMMUNICATION SYSTEM-III AT SOUTHERN METHODIST UNIVERSITY
                       Bryan Beeman and Murat M. Tanik
                                February 1989

Project Goal:   To bring the AT&T Videotex Communication  System at SMU to an 
operational state.~--~This report discusses the varied aspects of the system, 
beginning  with a  description of  the system,  containing both  physical and 
functional descriptions  of each system module.  The  next part of the report 
is  a  comprehensive  systems  analysis  covering  all  aspects  of  the VCS, 
concentrating on  the major conceptual  elements: the frame  creation module, 
the host computer, and  the array of public access terminals.  The discussion 
then covers the progress  of the project toward the project goal and problems 
encountered along  the way.  Following  this is a  summary of what  to expect 
from the available documentation. 
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89-CSE-5.                                                            ($1.00)

          ACTIVE DESIGN COMPONENTS FOR MULTIPROCESSING APPLICATIONS
                      M.G. Christiansen and M.M. Tanik
                                February 1989

~~~~~This  paper  describes  our  efforts  in  creating  support  for  design 
applications  which  require  the  presentation  and  manipulation of rapidly 
evolving   systems,   with   an   emphasis   on  developing  software  design 
environments.  This support  takes the form of active  design components that 
interact  and  evolve  as  a  community  towards  an  implementation  of  the 
application being developed.  An objective of this work is the development of 
domain  specific abstractions  for specific  classes of programming problems.  
Multiprocessing, or  parallel programming provides  the basis for  the set of 
components  we  have  implemented  and  utilize  in the implementation in our 
prototype environment.
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89-CSE-6.                                                            ($2.00)

                  SMU/SEAS NETWORK SIMULATION IN PAWS/GPSM
                      Greg S. Moore and Murat M. Tanik
                                February 1989

~~~~~This project  concerns the use of the  PAWS software package to evaluate 
and generate a performance analysis of the School of Engineering  and Applied 
Sciences computer  network at SMU.   The project has  been developed over two 
semesters because of the large  amount of computer network information needed 
and  the  complexity  of  PAWS.   This  report  outlines the entire procedure 
followed  during  the  course  of  this  project.  All work has been directed 
towards the development of  the PAWS (Performance Analysts  Workbench System) 
program which generates performance analyses of the SEAS computer network.
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89-CSE-7.                                                            ($3.00)

      REQUIREMENTS SPECIFICATION FOR A REAL-TIME EMBEDDED EXPERT SYSTEM
         Sang C. Suh, Frank Coyle, Dennis J. Frailey, Murat M. Tanik
                                February 1989

~~~~~Several commercial expert system  shells, among them Texas  Instruments' 
PC Plus, provide knowledge engineers with the capability of developing expert 
system  applications.   While  such  systems  provide  a range of development 
tools, they are not able to meet the size constraints or provide the run-time 
performance needed to address  problems associated with delivery  of embedded 
real-time  applications.   Furthermore,  there  is  no  provision  to provide 
deliverable code in Ada--a requirement for many DoD systems.

~~~~~The Embedded Consultant project is intended to address these issues by a 
two-fold  approach:  a)  knowledge  base  size  reduction  by  means of "code 
optimization" techniques; b)  an inference engine,  written in Ada,  designed 
for real-time applications.  The project was begun at Texas Instruments under 
IDEA program funding.  The  project  was transferred to  SMU in the Summer of 
1988.
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89-CSE-8.                                                            ($1.50)

                          WORKING-SET COPROCESSOR*
                              Milan Milenkovic
                                 March 1989

~~~~~Although the  working-set theory  provides a  sound basis  for efficient 
management of virtual  memory, few if any  faithful practical implementations 
of it  have been reported.   The primary obstacle  lies in the  apparent O(n) 
time  complexity of  per-reference accounting  of page  usage required by the 
definition of the working set, where n is the working-set size of the process 
under consideration.
~~~~~This  paper  describes  the  algorithmic  and  architectural design of a 
specialized  coprocessor capable  of tracking  the working  set of  a running 
process  with  100%  accuracy  in  real  time.   A  customized combination of 
hashing, timer processing, and  hardware assists is employed to  achieve O(1) 
average  time  complexity  of  the  operations involved in per-reference page 
accounting. 
~~~~~Results  of  a  trace-driven  simulation  of the working-set coprocessor 
(WSC)'s  operation  are  presented  to  demonstrate  the  feasibility  of the 
working-set  coprocessor's  implementation  using  components  no faster than 
those  of  the  cache  memory,  and  to  provide  some related implementation 
suggestions. 

*~This work was partially supported by IBM Corporation.  Limited distribution 
~~of this  paper will take place in the  form of a technical report published 
~~by IBM.
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89-CSE-9.                                                            ($1.00)

               REQUIREMENTS STUDY FOR A COMPUTING ENVIRONMENT
                  FOR ENGINEERING EDUCATION USING X-WINDOWS
                 Frank P. Coyle, Sang C. Suh, Murat M. Tanik
                                 March 1989

~~~~~Preliminary  requirements  for  a  network-based  computing facility for 
engineering  education were  defined based  on interviews with administrative 
staff of the  School of Engineering.   Prototype graphic interfaces  based on 
Suntools  and X-Windows  were developed  that permitted  icon-based access to 
system  functions.   X-Windows  was  found  to  be  extremely  useful  in the 
development  of  graphical  interfaces  and  provided  insights into possible 
extensions of this work in the area of intelligent user interfaces.
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89-CSE-10.                                                           ($1.75)

             UNIT OF CONSISTENCY IN OBJECT ORIENTED DATA BASES*
                  Francisco Mariategui and Margaret H. Eich
                                 March 1989

~~~~~We present  a new  model for transactions in  Object Oriented Data Bases 
(OODB).   This  model  captures  the  shape  of transactions by following the 
behavior of  the message  passing mechanism  inherent in  the object oriented 
paradigm.  We call  this new kind of transaction, "The  Pair <GM, DM>".  This 
dynamic model gives rise to tree structured transactions.  The end product of 
this  structure are  data base  accesses.  Our  model builds a bridge between 
message passing,  by which  objects communicate,  and data  base accesses, by 
which transactions communicate.  Thereby  closing the gap between the dynamic 
view of the world (objects) and the static view of the world (data bases).

*~This  material is based in  part upon work supported  by the Texas Advanced 
~~Research Program (Advanced Technology Program) under  Grant No. 2265 and by 
~~the National Science Foundation under Grant IRI-8713654.
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89-CSE-11.                                                           ($2.25)

            MULTI-GROUP MULTI-LAYER CONCURRENCY CONTROL IN OODBs*
                  Francisco Mariategui and Margaret H. Eich
                                 March 1989

~~~~~We propose a multi-group multi-layer approach to concurrency  control in 
Object  Oriented  Data  Bases  (OODB).   Our  proposed  architecture provides 
flexibility and adaptability in the sense  that it allows several concurrency 
control techniques  to coexist in the same  system.  OODBs have the potential 
to handle a variety of environments and this capability must be matched  with 
an appropriate mechanism to handle concurrency.
~~~~~We specify  the workings  of a  Concurrency Control  Manager Module that 
handles several groups  of transactions in  parallel.  We also  decompose the 
concurrency  control  mechanism  into  pieces.   Each  one  of  these  pieces 
accomplish a specific function and represent different levels  of abstraction 
in  concurrency  control  processing.   The  resulting  module  provides  the 
underlying technology to make our approach feasible.

*~This  material is based in  part upon work supported  by the Texas Advanced 
~~Research Program (Advanced Technology Program) under  Grant No. 2265 and by 
~~the National Science Foundation under Grant IRI-8713654.
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89-CSE-13.                                                           ($1.50)

     SYSTEM SPECIFICATION WITH COMMUNICATING SEQUENTIAL PROCESSES (CSP)
         Sanjive Agarwala                       Murat M. Tanik
      Texas Instruements Inc.            Southern Methodist University
                                 April 1989

~~~~~Communicating Sequential Processes (CSP) is an abstract, formal model of 
information flow, particularly suited in describing and analyzing systems and 
applications  that   may  exhibit   multiple  concurrent   and  communicating 
activities.   This  study  is  aimed  at  applying  the basic ideas of CSP in 
hardware design and finding  if this approach yields some  practical benefits 
in terms of coping with complex system design problems, with comparative ease 
of design.  CSP can provide  formalisms that truly express concurrency from a 
very high  level of behavioral  abstraction, where the  architect is still in 
control.  The  basic CSP  primitives are  very suggestive  of their  possible 
realization in terms of hardware components.  Moreover, we believe that there 
is a  commonality in  hardware and  software design  and thus  we may  find a 
significant  applicability of  the new ideas   of structured programming  and 
CSP to yield some practical benefits for system design and specification. 
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89-CSE-14.                                                           ($2.25)

                    STUDIES ON MULTI-PEG TOWERS OF HANOI
        Sam S. Chen, Ching-chao Liao*, David Y.Y. Yun, Murat M. Tanik
                                 April 1989

~~~~~A heuristic approach  named bipartite consecutive-disk  decomposition is 
proposed as a divide-and-conquer problem solving paradigm so that its optimal 
can be  the upper  bound solution  on the  required number  of moves  for the 
multi-peg Towers of  Hanoi, i.e. the problem of moving  n disks from a source 
peg to  a destination peg with  the aid of k  additional working pegs.  After 
limited  exploring  on  some  interesting  cases  of  small  n, two heuristic 
evaluation  functions  in  terms  of  certain  u,  the  degree of working peg 
utilization,  are presented for  the optimal decomposition  and the effective 
prediction of  the required  number of  moves.  The  predication behavior  in 
terms  of  the  heuristic  evaluation  functions  is  analyzed  further.  The 
required  number  of  moves  is  shown  to  be of degenerate exponential with 
respect  to  the  number  of  disks  while  using  more  working  pegs  (k>1) 
successively.  If we  can let k  grow at a  certain constant rate  of n1/u/u, 
then the solution behavior can even be linear with 2un.

*~Visiting  scholar  at  SMU  in  1988,  Professor,  Chung Cheng Institute of 
~~Technology, Taiwan, Republic of China.
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89-CSE-15.                                                           ($2.00)

                  AN AGENT FOR INTELLIGENT MODEL MANAGEMENT
                      John I.C. Liu and David Y.Y. Yun
                  Dept of Computer Science and Engineering
                                 Gary Klein
                   Dept of Management Information Sciences
                       Edwin L. Cox School of Business
                      August 1987 (Revised April 1989)

~~~~~Decision Support Systems (DSS) and Expert Systems (ES) are both aimed at 
improving  decision-making.  Current DSS  usually concentrate on quantitative 
model methods  while ES  emphasize logic  and reasoning.   In this  paper, we 
review previous approaches used by DSS to handle decision models.  We propose 
an  extension  to  such  systems,  an  Agent for Intelligent Model Management 
(AIMM),  as  an  interface  between  DSS  and  the  users.   AIMM  utilizes a 
combination of  knowledge representations and reasoning  mechanisms to make a 
wide variety of  models available to decision  makers so that they  may apply 
these models without becoming involved in technical or procedural aspects  of 
implementation.   A  prototype  of  the  system  for  financial  problems  is 
described. 
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89-CSE-16.                                                           ($1.75)

        LCF:  A LEXICOGRAPHIC BINARY REPRESENTATION OF THE RATIONALS
             Peter Kornerup               David W. Matula*
            Odense University       Southern Methodist University
                                 April 1989

~~~~~A  new  binary  representation  of  the  rationals  derived  from  their 
continued  fraction  expansions  is  described  and  analysed.   The concepts 
"adjacency", "mediant"  and "convergent"  (best rational  approximation) from 
the  literature  on  Farey  fractions  and  continued  fractions are suitably 
extended to provide a  foundation for this new binary  representation system.  
Worst  case representation-induced  precision loss  for any  real number by a 
fixed length representable number of the system is shown to be at most 19% of 
bit  word   length,  with  no  precision  loss   whatsoever  induced  in  the 
representation of  any reasonably sized rational  number.  The representation 
is  proposed  as  host  for  a computer arithmetic synergistically supporting 
exact rational and approximate real computation.

*~This research was  partially supported by  the National Science  Foundation 
~~under grant DCR-8315289.
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89-CSE-17.                                                           ($1.00)

                              EXECUTE LOCKING*
                              Margaret H. Eich

~~~~~An  extension to two-phase  locking which synchronizes  the execution of 
procedures is  proposed.  This technique, Execute  Locking, is two-phase with 
respect  to  data  access  but  is  not  two-phase  with respect to procedure 
execution.  It is shown that serializability is maintained.

*~This  material is based in  part upon work supported  by the Texas Advanced 
~~Research Program (Advanced Technology Program) under  Grant No. 2265 and by 
~~the National Science Foundation under Grant IRI-8713654.
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89-CSE-18.                                                           ($1.50)

                   RAPID PROTOTYPING SYSTEM SPECIFICATION
                    Joseph S. Dancses and Murat M. Tanik
                                  May 1989

~~~~~We  present  System  Level  Specification  of a Rapid Prototyping System 
including  development  environment,  a  programming  language, and the human 
interface in accordance with the guidelines provided by DoD-STD-2167A.
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89-CSE-19.                                                           ($1.00)

  AN EXPOSE-AND-MERGE ALGORITHM AND THE CHROMATIC NUMBER OF A RANDOM GRAPH*
                     David W. Matula and Ludek Kucera**
                                  May 1989

~~~~~A   randomized  algorithm  is  described  employing the expose-and-merge 
paradigm to create and color random graphs.  An  analysis of the algorithm is 
then employed to resolve a conjecture about the chromatic  number of a random 
graph, where specially we prove that almost surely 


           xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx


~*~This  paper  is  to  appear  in  the Proceedings from the Third Seminar on 
~~~Random  Graphs  and  Probabilistic  Methods  in Combinatorics and Computer 
~~~Science held in Poznan, Poland Aug. 1987 (to be published by Wiley).

**~Professor Kucera is on leave from Charles University, Prague, Czechosolvakia.
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89-CSE-21.                                                           ($1.50)

  REAL-TIME EMBEDDED EXPERT SYSTEMS AND KNOWLEDGE-BASE TRANSLATION PROBLEM
         Dennis J. Frailey, Sang C. Suh, Frank Coyle, Murat M. Tanik
                                  June 1989

~~~~~A wealth of tools are now available for expert system development.  Most 
of  these utilize  powerful computing  resources, including  fast processors, 
symbolic   programming   languages,   large   main  memories,  and  extensive 
interactive  graphics  support.    Although  well  suited  to  expert  system 
development, such  computing systems  are inappropriate  for certain embedded 
real-time environments in which limited  memory sizes, conventional processor 
architectures,  standard  programming   languages  and  serious   reliability 
considerations apply.  Moreover, embedded systems typically have little or no 
need for interaction with  an operator,  but have  important requirements for 
time-critical, interactive operation with other programs and equipment.
~~~~~This report  focuses on  automatic translation  of knowledge  bases into 
structures that can  be manipulated in conventional programming environments.  
Several opportunities are described  for accomplishing this goal.  Techniques 
from   compiler  code   optimization  are   identified  that  can  facilitate 
translation  of  knowledge  bases  into  compact data structures suitable for 
processing with a  small inference engine.   An experimental effort  using an 
Ada  inference  engine  is  described.   Potential problem areas of real-time 
systems are classified in an appendix.
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89-CSE-22.                                                           ($3.50)

           THE LISP PROGRAMMING LANGUAGE: TUTORIAL AND EXPERIENCE
                Terry L. Colvin, Frank Coyle, Murat M. Tanik
                                  June 1989

~~~~~LISP was developed in the late 1950's by John McCarthy, making it one of 
the oldest  programming languages still in use.  It was designed specifically 
for list  processing--the manipulation  of symbolic  information.  Because of 
LISP's  power and  flexibility, it  is the  most widely  used language in the 
field of artificial intelligence.
~~~~~Although  there are  several dialects  of LISP,  no single  one has been 
accepted as a uniform standard.  The versions of LISP used in this paper will 
be Common Lisp,  defined by Guy Steele in his book Common  Lisp: The Language 
and Franz LISP,  which was developed in the early 1980's at the University of 
California at Berkeley. 
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89-CSE-23.                                                           ($2.00)

                       THE EVOLUTION OF RANDOM GRAPHS
                              Michal Karonski*
                                  June 1989

~~~~~Let us adopt a dynamic view  in which a  graph,  acquiring edges,  grows 
from empty  to  complete.  More  precisely,  start  with n labelled  vertices     
{1, 2, ...,  n} and add edges at random,  one at a time,  until the resulting 
graph is complete.   This simple model of a graph evolving in a random manner 
was first investigated in detail by Erdos and Renyi (1960).  The key question 
they posed  may be  stated in  general terms  as follows:  what is  a typical 
structure  of a random graph  during its evolution?  We  say that a structure 
(or  a graphical property)  is typical if  a random graph  posseses it almost 
surely, i.e., with probability tending to one as the number of vertices tends 
to  infinity.   This  whole  section  is,  to  a large extent, devoted to the 
description of various problems arising from this basic question.

*~Professor Karonski is on leave from the Department of Discrete Mathematics, 
~~Adam Mickiewicz University, Poznan, Poland.
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89-CSE-24.                                                           ($1.00)

                   MICROPROCESSOR MEMORY-MANAGEMENT UNITS
                              Milan Milenkovic
                                  June 1989

~~~~~This report  describes the current crop  of commercial memory management 
units (MMUs) for 32-bit microprocessors of both CISC and RISC varieties.  The 
purpose of  this study  is to  review and  compare the  design principles and 
features  of high-end MMUs across  a common set of  criteria.  In addition to 
covering  traditional support for  virtual memory, consideration  is given to 
support for Unix-style  of memory management and  for multiprocessor/multiple 
MMU configurations.
~~~~~Section  1  of  this  report  contains  an  overview  of  the rationale, 
principles, and issues related to hardware support for  memory management and 
virtual memory.  Section  2 contains brief  overviews of the  following MMUs: 
Intel~80386,   486,   860,   Motorola   MC68851  (MMU  for MC68020), MC68030, 
MC68040, MC88200  (MMU for 88K  series), SPARC MMU  Fujitsu MB86920, and MIPS 
R2000/R3000.  Discussion and closing remarks are presented in Section 3 which 
also contains a tabulated summary of the presented MMUs. 
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89-CSE-25.                                                           ($1.00)

                             ON HAMMING NETWORKS
                      Wen-Kuang Chou and David Y.Y. Yun
                                  June 1989

~~~~~A  revised Hamming  net is  proposed, validated,  and tested.   Both the 
original   Hamming  net  and   the  revised  model   have  been  implemented.  
Experimental  results show  the equivalence  of both  models in the noiseless 
cases, but show dramatic improvements in classification problems with  noise.  
A proof of the convergence theorem for the revised model is given.
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89-CSE-26.                                                           ($1.25)

               INTERFACE DESIGN ISSUES IN A LABORATORY SETTING
Mary Lynne Morrow, Maria Fafouti-Milenkovic, Pari Sadagousheh, Murat M. Tanik
                                  June 1989

~~~~~This is a report of the research conducted  on behalf of Abbott Hospital 
Supply.   It states  the particular  "needs" of  Abbott that  the research is 
addressing and the specific  objectives and goals for the first  phase of the 
research  project.  The  report includes  data from  a pilot study (interview 
responses of lab  technicians from different  hospital and laboratory  sites) 
and the preliminary analysis of the results collected so far.                
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89-CSE-27.                                                           ($2.50)

             A SYSTEMS DESIGN APPROACH TO A CONCURRENT EMBEDDED
                    SYSTEM DESIGN PROCESS AND ENVIRONMENT
                    Geoffrey C. Hingle and Murat M. Tanik
                                  June 1989

~~~~~This   paper  presents   a  "System   Design-system"  (SD-system)  which 
efficiently  integrates  the  people  involved  in  the  management,  design, 
development,  testing,  production  and  maintenance processes of large-scale 
embedded systems.   The design  of large  embedded hardware/software  systems 
such  as an  aircraft requires  the involvement  of many people before design 
requirement decisions can be made.  System requirements must be developed and 
negotiated  between  people  and  corporations  concurrently  as the embedded 
systems of a large system  are developed.  Therefore, design methods  such as 
structured design can be used more efficiently  in the system design of these 
large embedded  systems, if the  structured design methodologies  support the 
design interaction of  many people and corporations.  The  people involved in 
embedded  system design are  the 'glue' that  connect the design processes of 
each embedded system  development into a single  process for the design  of a 
total  system  of  embedded  systems.   We  believe,  in order to instantiate 
efficient  system engineering  methods during  the concurrent  development of 
large embedded systems, we must design a SD-System which efficiently connects 
the  "Human-Objects" (system  designers) involved  in the  concurrent design, 
development,  test, production, and  maintenance of a  large embedded system.  
This is the main thrust of our paper.
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89-CSE-28.                                                           ($1.00)

       A SIMULATION TECHNIQUE TO CONSTRUCT PARALLEL EXECUTION PROFILE
                   FROM SEQUENTIAL TRACE OF LOGIC PROGRAMS*
                     Chin-Feng Fan and Prasenjit Biswas
                                 April 1989

~~~~~A fast way of estimating the performance of different parallel execution 
models for logic  programs is presented.  This  technique constructs parallel 
execution profile from sequential trace information.  A  performance tool can 
be  conveniently  realized  with  which  the  speed  up,  effect  of  varying 
granularity of tasks, parallel execution overheads, and distribution of tasks 
can be examined without actually executing benchmark programs.  This approach 
includes  three  steps:  acquiring  sequential  trace  of  a  Prolog program, 
converting  it  into  task  trace,  and  executing  the  program based on the 
simulated model using the trace.  The difficulties of this process are caused 
by  the  backtracking   and  nondeterministic  features  of  logic  programs.  
Conceptually a  multi-dimensional execution  tree of  a benchmark  program is 
reconstructed  from  its  sequential  trace  for  a  simulated  model.   This 
technique saves a substantial amount of evaluation  time in comparison to the 
frequently  used technique  of simulation/emulation  based on instruction-by- 
instruction  execution of complied  logic programs.  It  can be realized as a 
general simulation  tool to gain  further time saving.   Visualization of the 
resulting execution tree can easily be included in the future.  The technique 
has  been  implemented  to  compare  two different parallel models supporting 
different granularities of tasks.

*~This research was supported  by Texas Advanced Technology Program  Contract 
~~3128 (1988).

  Appeared in Proc. of 22nd Annual Simulation Conf., Pittsburgh, May l989.
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89-CSE-29.                                                           ($1.00)

ABSTRACT MACHINE LORAP II AND EXPERIMENTS IN PROCESS GRAIN SIZE DETERMINATION
                  FOR PARALLEL EXECUTION OF LOGIC PROGRAMS*
                     Chin-Feng Fan and Prasenjit Biswas
                                  May 1989

~~~~~In this  paper we propose  a distributed multiprocessor  execution model 
LORAP  II for  parallel execution  of logic  programs.  Each processor in the 
abstract machine  is capable of supporting processes  of variable grain sizes 
and is  designed to be  competitive with existing  sequential implementations 
for deterministic cases.  We present a set of experiements that establish the 
requirement  for determining  appropriate process  grain sizes  for effective 
parallel processing.   Some heuristics are  presented for compile  time grain 
size  determination.  Finally, we present  some results from our experiements 
using the heuristics, that  indicate a significant improvement in performance 
over a similar model (LORAP) supporting fine grain processes.

*~This research  was supported by  Texas Advanced Technology Program Contract 
~~3128 (1988). 

  A shorter version has appeared in Proc. of IEEE Symp. on Tools for AI 
  (Architecture, Languages and Systems), Virginia, Oct. 1989.
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89-CSE-30.                                                           ($1.00)
                       A MODEL FOR MULTIPROCESSOR I/O
                              Milan Milenkovic
                                  July 1989

~~~~~Recent  advances in  processor architecture  and memory  technology will 
likely continue to contribute to increases of computational power of computer 
systems.   However, the  lack of  corresponding improvements  in input/output 
throughput results in somewhat unbalanced systems designs.
~~~~~This  paper  proposes  an  architectural  approach  for  increasing  the 
performance of I/O, especially in multiprocessors and in distributed systems.  
The proposal calls for  a considerable increase of I/O subsystem autonomy and 
self-sufficiency by means of encapsulation of  I/O hardware and software into 
dedicated  processing  complexes  termed  server  engines.  The server-engine 
approach  is  suited  to  the  specific  needs  of  input/output,   including 
longevity,  burstiness,  event-driven  and  time-critical  nature.  The paper 
describes the basic structure and several different types of server engines. 
~~~~~The functional decomposition and encapsulation  of I/O operations within 
server engines  provide some significant benefits  in multiprocessor systems.  
The major ones  include improved I/O performance,  increased parallelism, and 
significant reduction of the load on the shared system-interconnection paths.
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89-CSE-31.                                                           ($2.50)

           DATABASE PARTITIONING TECHNIQUES TO SUPPORT RELOAD IN A
                     MAIN MEMORY DATABASE SYSTEM:  MARS
                      Le Gruenwald and Margaret H. Eich
                               September 1989

~~~~~In  a main memory database  system, the primary copy  of the database is 
placed in volatile memory.  When a crash occurs, a partial or complete reload 
of the database from archive memory (AM) into main memory (MM) is needed.  To 
effectively  perform  the  reload   process  without  degrading  the   system 
performance, the most effective technique for structuring AM and MM should be 
determined.  This paper reports on experiments performing a complete analysis 
of possible partitioning techniques in terms of the number of I/Os for reload 
and  number  of  MM  references  incurred during transaction processing.  Our 
analysis shows that horizontal and  single vertical partitioning are actually 
the only  possible candidates.   Which one  is best  depends on  the types of 
transactions executed.
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