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Communications of the ACM

Table of Contents


Editorial: Childhood's end


ACM forum


From Washington: Secrecy versus scientific communication

There are many issues that affect the health of science but none more pervasive than the problem of “secrecy vs. scientific communication.” Unfortunately much of the debate on this issue, which is concern to all scientists, is …

Programming pearls: Aha algorithms

The study of algorithms has much to offer the practicing programmer. After just a course or two on the subject, students take away algorithms for solving many important tasks and design techniques for attacking new problems.  …

Introduction to the fifth generation

In October 1981, Japan's Ministry of International Trade and Industry (MITI) sponsored a conference to announce a new national project. Alongside national projects in supercomputing and robotics, there would be an effort to develop …

The Japanese approach: a better way to manage programmers?

With a turnover rate among computer programmers of 25%-50% per year, it's time somebody came up with a better way to manage computer professionals. One approach that holds promise is to create a Japanese-style Theory Z atmosphere …

The fifth generation project — a trip report

As part of Japan's effort to become a leader in the computer industry, the Institute for New Generation Computer Technology has launched a revolutionary ten-year plan for the development of large computer systems which will be …

Cooperation is key: an interview with B. R. Inman

The most innovative and audacious among the U.S. responses to Japan's Fifth Generation Project is that of the Microelectronics and Computer Technology Corp. MCC is a consortium of thirteen companies formed to conduct long range …

A simple database language for personal computers

A simple database language for personal computers has been implemented by selecting a subset of the ANS MUMPS language and enhancing it so as to meet the requirements of microcomputer end-users who are unfamiliar with computers …

A practical tool kit for making portable compilers

The Amsterdam Compiler Kit is an integrated collection of programs designed to simplify the task of producing portable (cross) compilers and interpreters. For each language to be compiled, a program (called a front end) must  …

An empirical study of insertion and deletion in binary search trees

This paper describes an experiment on the effect of insertions and deletions on the path length of unbalanced binary search trees. Repeatedly inserting and deleting nodes in a random binary tree yields a tree that is no longer …

Optimal paths in graphs with stochastic or multidimensional weights

This paper explores computationally tractable formulations of stochastic and multidimensional optimal path problems, each as an extension of the shortest path problem. A single formulation encompassing both problems is considered …

A diagnosis of beginning programmers' misconceptions of BASIC programming statements

In the process of learning a computer language, beginning programmers may develop mental models for the language. A mental model refers to the user's conception of the “invisible” information processing that occurs inside the …

A quadtree medial axis transform

As printed

Quadtree skeletons are exact representations of the image and are used because they are observed to yield space efficiently and a decreased sensitivity to shifts in contrast with the quadtree. The QMAT can be …