bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mathematics education through the perspective of rationalized APL
Authors: Alvord Linda 
Published: January 2007

Mathematics expresses concepts by the use of a symbol system. The symbols include the familiar plus + , minus - , times x and divide ÷ . APL extends the conventional mathematical symbol system to include major ideas such as power, maximum and deal. These powerful ideas are expressed in simple APL symbols like *, ⌈, and ?. These functions require two arguments represented by the two Greek letters
alpha
and
omega
. They are generalized with the expressions α*ο α⌈ο and α?ο. The symbols have functions which are monadic counterparts called exponential, ceiling and roll when they have only one argument as in *ο, ⌈ο and ?ο.

The mind comprehends and manipulates increasingly complex concepts expressed in these abstract symbols. New thoughts and ideas are generated in response. On occasion, new concepts warrant symbols of their own. This paper demonstrates a strategy for teaching students the process of developing an extended symbol system of their own.
In education, teachers help learners to read and interpret what already exists. In addition, just as writers learn by expressing concepts in their own sentences, mathematicians need to experiment with the process of “symbol building” to learn the essential nature of mathematics. The example which follows shows the development of a “meaning” for the symbol. In the monadic case, ο, the function produces a frequency distribution of the elements in the numeric array argument. In the dyadic case, α ο, the result is a frequency distribution of the elements in the literal array argument entered in ο which are contained in the array provided in α.

Implementing the method requires both direct definition and
Rationalized APL
by Kenneth Iverson which proposes the use of the
del
operator to allow the APL user to make a function represented by a single symbol. The del operator creates a function which has both a monadic and a dyadic definition and consequently is called ambivalent. Learning to use these tools allows the student to experiment as a creator of mathematical language.
Monit: a performance monitoring tool for parallel and pseudo-parallel programs
Authors: Kerola Teemu , Schwetman Herb 
Published: January 2007

This paper describes a performance monitoring system, Monit, developed for performance evaluation of parallel systems. Monit uses trace files that are generated during the execution of parallel programs. Monit analyzes these trace files and produces time-oriented graphs of resource usage and system queues. Users interactively select the displayed items, resolution, and time intervals of interest. The current implementation of Monit is for SUN-3 workstation, but the program is easily adaptable to other devices.
We also introduce a parallel programming environment, PPL, implemented as a superset of C for the Sequent Balance 8000 multi-processor system. Parallel programs written in PPL can produce the trace files for Monit.
Monit is also integrated into a process-oriented simulation language CSIM. CSIM allows the creation of simulation models based on multiple processes competing for resources. The similarity between parallel processes in PPL and pseudo-parallel processes in CSIM facilitates this combined use of Monit.
Workload characterization (tutorial)
Authors: Ferrari Domenico 
Published: January 2007

Workload characterization is that branch of performance evaluation which concerns itself with the measurement and modeling of the workloads to be processed by the system being evaluated. Since all performance indices of interest are workload-dependent, there is no evaluation study that does not require the characterization of one or more workloads. In spite of the importance of the problem, our knowledge in this area leaves much to be desired.
The tutorial addresses the main issues, both resolved and unresolved, in the field, and surveys the major approaches that have been proposed and are in use. Modern methods for designing executable artificial workloads, as well as the applications of these techniques in system procurement, system tuning, and capacity planning are emphasized.
On the availability of a distributed computer system with failing components
Authors: Gelenbe Erol , Finkel David , Tripathi Satish K. 
Published: January 2007

We present a model for distributed systems with failing components. Each node may fail and during its recovery the load is distributed to other nodes that are operational. The model assumes periodic checkpointing for error recovery and testing of the status of other nodes for the distribution of load.
We consider the availability of a node, which is the proportion of time a node is available for processing, as the performance measure. A methodology for optimizing the availability of a node with respect to the checkpointing and testing intervals is given. A decomposition approach that uses the steady-state flow balance condition to estimate the load at a node is proposed. Numerical examples are presented to demonstrate the usefulness of the technique. For the case in which all nodes are identical, closed form solutions are obtained.
The local disk controller
Authors: Houtekamer Gilbert E. 
Published: January 2007

The performance of the I/O subsystem in the 370-XA architecture has been improved considerably with the introduction of the new channel subsystem, as compared to the System/370 architecture. The emphasis in the 370-XA architecture is on reducing the CPU load associated with I/O, and on reducing the congestion in multi-CPU, shared systems, by redesigning the channel system.
In this paper we will show that a reallocation of the control unit logic may triple the channel subsystem's capacity, while still using the same disk drives. The performance gain is achieved by adding control-unit like intelligence and local buffer memory to each disk drive, creating a Local Disk Controller (LDC), and thus eliminating the performance degradation caused by reconnect failures at a high channel utilization. The system proposed remains fully software compatible with the current 370-XA architecture. A simpler approach, requiring only a slight modification to the disk drives, is also discussed.
Memory system behavior of Java programs
Authors: Kim Jin-Soo , Hsu Yarsun 
Published: January 2007

This paper studies the memory system behavior of Java programs by analyzing memory reference traces of several SPECjvm98 applications running with a Just-In-Time (JIT) compiler. Trace information is collected by an exception-based tracing tool called JTRACE, without any instrumentation to the Java programs or the JIT compiler.
First, we find that the overall cache miss ratio is increased due to garbage collection, which suffers from higher cache misses compared to the application. We also note that going beyond 2-way cache associativity improves the cache miss ratio marginally. Second, we observe that Java programs generate a substantial amount of short-lived objects. However, the size of frequently-referenced long-lived objects is more important to the cache performance, because it tends to determine the application's working set size. Finally, we note that the default heap configuration which starts from a small initial heap size is very inefficient since it invokes a garbage collector frequently. Although the direct costs of garbage collection decrease as we increase the available heap size, there exists an optimal heap size which minimizes the total execution time due to the interaction with the virtual memory performance.
APL2 implementation of numerical asset pricing models
Authors: Foote W. , Kraemer J. , Foster G. 
Published: January 2007

The practice of modern finance theory depends on an ability to generate accurate and timely forecasts of asset returns. In this field, considerable effort has been expended to base the generation of asset returns on a set of state variables driven by the dynamics of the environment.
This requires the solution of a fundamental parabolic partial differential equation, often with variable coefficient, and with a wide range of specification of boundary and initial value conditions. A major drawback in financial management of large, real-time problems of this sort is that they require numerical intensive computing. Approximations or simplifications are used. The one state variable model of Black and Scholes [Bla73] leads to a closed form solution of the value of a call option, as explored in an APL solution by Bogart [Bog87].
The two state variable model of Brennan and Schwartz [Bre79, Sch84] determines the value of an intermediate maturity bond whose value depends upon the dynamic evolution of: a short-term rate, such as the 3 month Treasury Bill rate, and a long term rate, such as the 30 year Treasury bond rate. This solution does not have a closed form and must be solved numerically or approximately.
This paper describes a formulation of the Brennan and Schwartz model; develops a finite difference representation; describes the strategy for an APL2 implementation; and illustrates the results with the run of an application.
Flexi-View: a multi-dimensional data modeling system
Authors: Friis E. S. , Goldberg J. A. 
Published: January 2007

This paper addresses the basic components of a system which facilitates the modeling of multi-dimensional data in terms of a relational database table. The name of the system is FLEXI-VIEW (XVU). FLEXI-VIEW is implemented in APL2 and runs on the IBM Virtual Machine/System Product (VM/SP) operating system.
FLEXI-VIEW interfaces, via the auxiliary processors AP126 and AP127, to the Graphical Data Display Manager (GDDM) and the Structured Query Language Data System (SQL/DS).
SQL is the centerpiece of the FLEXI-VIEW architecture. It was chosen in February of 1985 by the American National Standards Institute (ANSI) as the standard language for relational Data Base Management Systems (DBMS). In addition, IBM has chosen SQL as its strategic relational DBMS product.
The Interactive Chart Utility (ICU) is invoked by FLEXI-VIEW to deliver full-screen graphics and business charts. ICU is a component of GDDM which is responsible for creating, managing, and delivering the system's full-screen panels. Each panel is programmed function (PF) key and window driven.
VM/SP, APL2, SQL/DS, and GDDM/ICU are IBM Program Products.
Indexing and merging in APL
Authors: Gerth J. A. , Orth D. L. 
Published: January 2007

Mathematically, an array may be usefully viewed as a function, in this particular case, as a function of its indices. A proposal is made for an operator which derives such a function for its array operand.
The proposal is discussed in the context of a review of indexing constructs in various APL systems.
The use of APL.68000 access to the Macintosh quickdraw system for the productio n of shadows cast by buildings
Authors: Julian W. G. 
Published: January 2007

This paper describes the considerations involved in predicting the shapes of shadows cast by buildings for any hour, day or month of the year and for any location on Earth.
The power of APL is demonstrated in the general solutions possible for the problem irrespective of the shape of the building provided that it is composed of regular cylinders or prisms.
Direct access to the Macintosh Quickdraw functions allows the production of graphical output of high resolution and using any of the available printing fonts.
The system described makes use of Macintosh menus and dialogue boxes for data input and workflow control. The result is a system with an appearance similar to other Macintosh applications, such as, MacWrite, Word or MacDraw and the user is unaware of the presence of APL.
Comparative analysis of LISP and APL2
Authors: Kaneko A. 
Published: January 2007

LISP and APL2 were both born in 1960's and they have the similar syntax which is called function type.
The main users of LISP were in the universities and the applications were linguistics or formula processing in mathematics.
On the other hand APL was used in the companies and many of their applications were in the business environment such as business planning or reporting.
Traditional APL provided user intuitive expressions, but it was rather weak in handling character string of variable length or combination of numerics and characters.
APL2 and its general array resolved these weak points and it has a great capability to develop AI applications.
This paper introduces the similarities between LISP and APL2 and shows how APL2 solves the problem which LISP is good at handling.
Network shared variable processor
Authors: Potyok R. L. 
Published: January 2007

The Network Shared Variable (NSV) and Network Shared Variable Processor (NSVP) provide a user signed on to a local SHARP APL system with the ability to communicate with a remote SHARP APL system over a communications interface by sharing a variable with a task on that remote system. More specifically, NSVP extends the shared variable protocol to allow communications between tasks on different computer systems.
Together, they represent dynamic innovations in APL technology that provide greater computing flexibility and power to the end user and the data centre. NSVP encourages users to maximize the potentials of distributed applications as it helps organizations optimize their data centre resources. NSVP also reinforces the image of APL at the forefront of system software technology.
The NSV, while transparent to the user after coupling, enables users to access data from other systems using just one set of commands, while it minimizes the human and hardware resources required to maintain the data centre.
In several ongoing tests of the NSV prototype, the product has proven its value to a variety of organizations around the world with substantially different needs.
Windows and pop-up menus in application design
Authors: Smith A. 
Published: January 2007

An increasing number of APLs support the 'Mac-like' interface, with its pioneering ideas of Windows, Icons, Mice and Pull-down Menus. Technically exciting these may be; what is lacking is any useful experience of handling these techniques in APL application design.
The author has tackled the problem from the application end: a collection of functions has been evolved (written in APL*PLUS/PC) to provide simple windows and menus using text characters only.
The major benefits of the windowing/menu approach are found to be: 1) portability of ideas. What runs now on the PC and the Amiga will largely run on VS APL under GDDM (Vn 2) on the mainframe. 2) simplicity of design. With windows you can throw away many of those AP124-type panels and revert to 'quote-quad' input. 3) ease of validation. With a scroll-bar selection, the user has no choice but to input a valid reply. 4) ease of use, and 'PC' feel. Why not make Lotus-123 users feel at home?
Typical applications include a shop-floor information system for chocolate manufacture, and a 'rule-inducing' expert system shell. Copies of the window functions are included at the end of this paper, or are available via the BAA Software Exchange.
MASCO
Authors: Fenner Jack N. , Schmidt Jeffery A. , Halabi Houssam A. , Agrawal Dharma P. 
Published: January 2007

The design of a host machine architecture for implementing an existing image machine architecture is considered. The proposed microarchitecture uses a microprogrammed control unit to emulate the Motorola MC6809 microprocessor architecture.
The detailed hardware characteristics of the proposed machine are described and the microinstruction set is defined. The microroutines that emulate the MC6809 instruction set have been developed. A practical implementation using current technology is studied and some realistic timing characteristics are determined. The simulation of the proposed architecture is reviewed and the performance is evaluated. Finally, comparisons with existing models are made and the results are discussed.
A new universal microprogram converter
Authors: Takahashi Kazutoshi , Takahashi Etsuo , Bitoh Tatsushige , Sugimoto Takao 
Published: January 2007

Following the software crisis, a firmware crisis has occurred.
Since too much man-power and time is needed to develop microprograms, the ones already produced like software have to be used as long as possible.
This paper describes a general purpose microprogram conversion tool which is one of the methods used to reduce the man-power and time required for microprogram development and examples of the execution results obtained using this tool.
Programming considerations for documentation and maintenance
Authors: Fleming Stephen C. 
Published: January 2007

The intent of this paper is to create, or reinforce among programmers an awareness of some simple measures which can be taken during application system development, which can save valuable time later, when somebody else is called upon to document, fix, enhance, or otherwise read and work with their programs.
Although the paper describes several approaches to system documentation, it is not expected that any programmer will henceforth develop his applications exclusively around and according to the needs of the technical writer or maintenance analyst. The hope is that by describing a broad range of techniques, individual programmers can select those which best suit their style and approach, while minimizing the imposition of rigid and burdensome “standards”. The premise being that some, any, assistance provided to future readers, is better than none.
A model for teaching APL: moving into the fast lane
Authors: Traberman Tama 
Published: January 2007

The business world is in the throes of an on-going revolution. In today's global business environment, managers must be smarter than the competition if they want to increase their market share and provide customers with new services and products that capture the imagination and new customer dollars. All stock brokers and investment bankers want to maximize their clients' investments. Yet some firms consistently are more successful than others in choosing the right investments for clients and at attracting new clients. Some retail chains go out of business while others flourish. What differentiates success and failure?
Smart managers in this ever-changing global market are discovering that APL and APL tools can give them a competitive edge. APL is a strategic tool that helps their staff members be more efficient, more effective and more creative on the job. And while it is true that people can learn APL on their own, good managers recognize that it is more efficient for employees to get professional instruction in APL. These managers recognize that their employees want to learn APL quickly. They want to learn the most current usage of the language in the context of the business applications they use on the job. Knowledgeable professionals want and need professional instruction that matches their job skills and competencies in order to accelerate the slope of their APL learning curve.
An object oriented extension to APL
Authors: Girardot Jean Jacques , Sako Sega 
Published: January 2007

This paper describes an object oriented extension of APL, which is currently being implemented in a new APL system. This extension is integrated in a rather conservative way to APL. However, all the paradigms of object oriented languages (message passing, instance variables, methods, classes and inheritance) are made available to the user, without losing any of the successful features of APL.
The paper first explains what are the interests of object oriented programming, and what is expected from this introduction in the language. It then discusses syntactic and semantic choices, and shows how the selected solutions fit the philosophy of APL.
An example of this new style of programming in APL is proposed, then the internals of the implementation are presented, showing that this new possibility is made available at the cost of a minimal system overhead. Finally, the paper discusses about the results obtained so far.
APL extensions—a users view
Authors: Jordan Maurice H. 
Published: January 2007

There has been much heated argument about extensions in APL. This paper reflects 5 years' experience with one brand of extensions (STSC's nested array system). Useful and irritating features are discussed.
Facilities available are compared with other implementations - APL2, Dyalog, and IPSA. Topics covered include event handling, file systems, strand notation, indexing, the each dual and rank operators, and interfaces to other languages. The paper is illustrated with examples drawn from code produced internally, and from VECTOR competitions.
TSIOPAK—a proposal for a new Sharp APL file system
Authors: Leon Carlos G. 
Published: January 2007

Communication between OS files is often necessary when information that is manipulated and stored in Sharp APL files is required to be used by non-APL routines. For example, one may use APL for number crunching and have the output processed by SAS or FORTRAN to plot the data.
The arising demand for procedures that would make data accessible from APL to other systems motivated the author to take action.
TSIOPAK was developed with the intention to provide a standard interface between Sharp APL and the MVS operating system facilitating the accessibility of data created through APL and other languages. In addition, the reader will find that starting from the section titled the TSIOPAK File System, the format for each section looks very much like the Sharp APL Reference Manual. This is not a coincidence, what the author has tried to achieve with this work is to have a file system functionally identical to Sharp's using OS files. The author's efforts have gone as far as trying to replicate the format of Sharp's manual.
In addition, parts of the Sharp APL File System have not been implemented in TSIOPAK due to the lack of time and resources. Hence, this paper is a proposal for a new file system which would make APL-generated data generally available.
An APL idiom inventory
Authors: Peell Howard A. 
Published: January 2007

An instrument is proposed for rating APL idioms. Scales include: Length □IO Independence Usefulness Efficiency Generality Clarity Simplicity Memorability Interestingness Elegance
This APL Idiom Inventory was pilot-tested by APL programmers and APL instructors who rated a dozen selected APL idioms. The results indicate which idioms they think are “useful”, “easy to learn”, “hard to remember”, “interesting”, etc. Implications for teaching and related issues are also discussed.
Infinite loops and how to create them
Authors: Searle John R. 
Published: January 2007

Infinite loops are the worst enemy of any programmer in any language. They waste potentially huge amounts of time, system resources and/or money, and can destroy the credibility of the programmer amongst colleagues or customers.
In APL, infinite loops can potentially occur wherever a loop is present. However, they can also occur wherever any branching statement is used, and can even occur where no branching instructions have been used. In order to avoid infinite loops, the programmer is best equipped if he/she is aware of all of the possible ways in which they may be created.
An APL function is also presented which will give programmers new to the language a means whereby most infinite loops can be avoided in their training phase.