The column, “Benchmarks for LAN Performance Evaluation,” by Larry Press (Aug. 1988, pp. 1014-1017) presented a technique for quickly benchmarking the performance of LANs in an office environment. This piqued our interest since office automation is growing in importance. As a result, an empirical analysis of the Press benchmark programs was conducted. The results indicated that these benchmarking programs were appropriate for the benchmarking of LANs in an office environment.
Software Engineering and Programming Languages
Advertisement
Putting innovation to work: adoption strategies for multimedia communication systems
Multimedia communication systems promise better support for widely distributed workgroups. Their benefits for complex communication—problem-solving, negotiating, planning, and design —seem obvious, introducing appealing new technologies into the marketplace, however, can require years of Investment [13, 22]. In particular, finding productive uses for new systems takes time. Adoption strategies are needed to guide and accelerate the process.
Collaboration is a sign of maturation. A child is nurtured at home before venturing into the world. An idea is first developed then introduced to a larger community. We work on a software module in isolation before integrating it.
This issue of Communications focuses on social and organizational influences governing collaborative uses of computers and communications. Here we review some of those influences from the perspectives of the risks involved.
Collaborative computing: collaboration first, computing second
These articles on Collaborative Computing will seem out of place to a number of readers from the computer science community. Interesting articles perhaps, but what do they have to do with computers? Where is the science—that is, where is the mathematics, or the code? What have these issues to do with everyday practice?
Designing for cooperation: cooperating in design
This article will discuss how to design computer applications that enhance the quality of work and products, and will relate the discussion to current themes in the field of Computer-Supported Cooperative Work (CSCW). Cooperation is a key element of computer use and work practice, yet here a specific “CSCW approach is not taken.” Instead the focus is cooperation as an important aspect of work that should be integrated into most computer support efforts in order to develop successful computer support, however, other aspects such as power, conflict and control must also be considered.
Supercomputing policy links science and the “C” word
Competition, a concept nary whispered in pure science circles, might just have been the catalyst that finally drove the High Performance Computing and Communication (HPCC) policy over the Hill. It has taken many years, and countless government studies, to help legislators even comprehend and appreciate the potential of high-performance computing technology in the U.S. But toss in the competitive angle, and the story needs little translation.
I read with interest Peter Pearson's article, “Fast Hashing of Variable-Length Text Strings” (June 1990, pp. 677-680). In it he defines a hash function, given a text C1 … CN, by Exclusive OR'ing the bytes and modifying each intermediate result through a table of 256 randomish bytes.
Programming parallel machines is very difficult. First, generating an algorithm requires the programmer to assimilate the interactions of multiple threads of control. Second, synchronization and communication among the threads must be addressed to avoid contention and deadlock. Then, once the program is executing on the parallel system and does not function correctly or performs poorly, the debugging of multiple threads is a complicated problem [21]. Additionally, debugging software is an activity that requires systematic attention to detail. Success is a function of the experienced individual involved and the tools employed. The ability to efficiently debug software requires the wisdom to know what questions to ask, the ability to analyze the answers received, and the knowledge to formulate the best next question. To aid in this interactive process, the programmer needs information about the run-time behavior of the program.
The 21st ACM North American computer chess championship
After twenty years of traveling from city to city across the United States, the ACM North American Computer Chess Championship came back to the place of its birth, the New York Hilton Hotel, where the competitions began in 1970. This latest five-round event ended in a two-way tie for first place between MEPHISTO and DEEP THOUGHT/88. Finishing in a two-way tie for third place were HITECH and M CHESS. A total of 10 teams participated, and the level of play was at the low grandmaster level. A special three-round end-game championship was won by MEPHISTO, who also captured the prize for the best Small Computing System. A total of $8000 in prizes was divided up among the winners.
Massively distributed computing and factoring large integers
Over the last 15 years the increased availability of computers and the introduction of the RSA cryptosystem has led to a number of new and remarkable algorithms for finding the prime factors of large integers. Factoring numbers is an arithmetic problem so simple to understand that school children are asked to do it. While multiplying or adding two very large numbers is simple and can be done quite quickly, the age-old problem of trying to find a number that divides another number still has no simple solution. Computer science has reached a point where it is starting to custom tailor the design of computers toward solving specific problems. This pracnique will discuss some of the more recent algorithms for factoring large numbers and how networks of computers can be used to run these algorithms quickly. Since this is a general exposition, we do not give detailed mathematical descriptions of the algorithms. We also allow ourselves to be somewhat casual with mathematical notation in places and hope that the mathematically sophisticated will forgive the looseness.
A national debate on encryption exportability
Traditionally, cryptography has been an exclusively military technology controlled by the National Security Agency (NSA). Therefore, U.S. International Traffic in Arms Regulations (ITARS) requires licenses for all export of modern cryptographic methods. Some methods, such as the Data Encryption Standard (DES), are easily obtained for export to the Coordinating Committee for Multilateral Export Controls (COCOM) countries, but not Soviet block countries, or most Third World nations.
Shape the Future of Computing
ACM encourages its members to take a direct hand in shaping the future of the association. There are more ways than ever to get involved.
Get InvolvedCommunications of the ACM (CACM) is now a fully Open Access publication.
By opening CACM to the world, we hope to increase engagement among the broader computer science community and encourage non-members to discover the rich resources ACM has to offer.
Learn More