Because comparison in the standard UNIX ™ operating system sort routine, /bin/sort, is interpretive, it is generally more time-consuming than the standard paradigm of comparing two integers. When a colleague and I mod...
Because comparison in the standard UNIX ™ operating system sort routine, /bin/sort, is interpretive, it is generally more time-consuming than the standard paradigm of comparing two integers. When a colleague and I modified sort to improve reliability and efficiency, we found that techniques that improved performance for other sorting applications sometimes degraded the performance of sort. Input and output are important when comparisons are simple, but as comparisons become more complex, the number of comparisons quickly dominates the performance of sort.
This paper presents a set of program transformations that are useful in transforming certain sequential program schemas for use in a local distributed environment. The environment is considered to be a set of processo...
This paper presents a set of program transformations that are useful in transforming certain sequential program schemas for use in a local distributed environment. The environment is considered to be a set of processors connected by a local area network with broadcast capability. Examples of transformedprogram schemas are given that implement shareddata, maximization, and abstract queues in a distributed environment.
This is the second issue of the Technical Journal devoted exclusively to papers on the family of computer operating systems bearing the UNIX trademark of AT&T Bell Laboratories. The UNIX operating system was creat...
This is the second issue of the Technical Journal devoted exclusively to papers on the family of computer operating systems bearing the UNIX trademark of AT&T Bell Laboratories. The UNIX operating system was created in 1969 by K. Thompson andd. M. Ritchie. Its growth since then, in both the commercial world and the research community, has been truly remarkable.
作者：
RABINER, LRPAN, KCSOONG, FKAT&T Bell Laboratories.Lawrence R. Rabiner:
S.B. and S.M. 1964 Ph.D. 1967 (Electrical Engineering) The Massachusetts Institute of Technology AT&T Bell Laboratories
1962—. Kok-Chin Pan:
S.B. and S.M. 1984 (Electrical Engineering and Computer Science) The Massachusetts Institute of Technology. From 1981 to 1984 Mr. Pan participated in a cooperative program in Electrical Engineering and Computer Science at AT&T Bell Laboratories. Frank K. Soong:
B.S. 1973 National Taiwan University M.S. 1977 University of Rhode Island Ph.D. 1983 Stanford University all in Electrical Engineering AT&T Bell Laboratories
1982—.
In this paper we present results of a series of experiments in which combinations of vector quantization and temporal energy contours are incorporated into the standard framework for the word recognizer. We consider t...
In this paper we present results of a series of experiments in which combinations of vector quantization and temporal energy contours are incorporated into the standard framework for the word recognizer. We consider two distinct word vocabularies, namely, a set of 10 digits, and a 129-word airlines vocabulary. We show that the incorporation of energy leads to small but consistent improvements in performance for the digits vocabulary; the incorporation of vector quantization (in a judicious manner) leads to small degradation in performance for both vocabularies, but at the same time reduces overall computation of the recognizer by a significant amount. We conclude that a high-performance, moderate-computation, isolated word recognizer can be achieved using vector quantization and the temporal energy contour.
Combining archival, ethnographic, vital, and oral historical data, this paper compares the experiences of population growth anddemographic transi tion among different social classes of a Sicilian rural town from 1850...
Combining archival, ethnographic, vital, and oral historical data, this paper compares the experiences of population growth anddemographic transi tion among different social classes of a Sicilian rural town from 1850 to the pres ent. Four locally named groups have dominated this town's social life during most of the period in question—gentry, artisans, landed, and landless peasants. Of particular concern are the contrasting patterns of demographic transition be tween the gentry and artisanry, and a consideration of why, in both cases, fertility decline occurred earlier than among landless peasants. Comparison underscores the theoretical advantage of disaggregating population change in relation to historical context and social class.
Accurate location of the endpoints of spoken words andphrases is important for reliable and robust speech recognition. The endpoint detection problem is fairly straightforward for high-level speech signals in low-lev...
Accurate location of the endpoints of spoken words andphrases is important for reliable and robust speech recognition. The endpoint detection problem is fairly straightforward for high-level speech signals in low-level stationary noise environments (e.g., signal-to-noise ratios greater than 30-dB rms). However, this problem becomes considerably more difficult when either the speech signals are too low in level (relative to the background noise), or when the background noise becomes highly nonstationary. Such conditions are often encountered in the switched telephone network when the limitation on using local dialed-up lines is removed. In such cases the background noise is often highly variable in both level and spectral content because of transmission line characteristics, transients and tones from the line and/or from signal generators, etc. Conventional speech endpoint detectors have been shown to perform very poorly (on the order of 50-percent worddetection) under these conditions. In this paper we present an improved word-detection algorithm, which can incorporate both vocabulary (syntactic) and task (semantic) information, leading to word-detection accuracies close to 100 percent for isolateddigit detection over a wide range of telephone transmission conditions.
The build tool is used as a sophisticated method of generating and modifying software systems. Build is being used successfully by a number of UNIX ™ software-based projects at AT&T Bell Laboratories. Build is an ...
The build tool is used as a sophisticated method of generating and modifying software systems. Build is being used successfully by a number of UNIX ™ software-based projects at AT&T Bell Laboratories. Build is an extension to the make program that permits several software developers to independently make a collection of software while sharing the same fully populated set of directories, with the changed files residing in their own directories. An important concept in using build is software view , which represents the selection of a particular version of software for a generation environment. For example, a developer's view of a software system generally includes all of the current “official” software perturbed by the developer's private modifications to the system. A testing team's view may be the current official software perturbed by changes that a set of developers have made and have submitted for project system testing. A system user's view is a fully tested and released version of the software. The function of build is to simplify the administration of the different views of the software system. The build tool is being used by a number of large software development projects as the primary software generation tool. Build plays a central role in the development strategies and standards used in these projects.
作者：
RABINER, LRWILPON, JGTERRACE, SGAT&T Bell Laboratories.Lawrence R. Rabiner:
S.B. and S.M. 1964 Ph.D. 1967 (Electrical Engineering) The Massachusetts Institute of Technology Bell Laboratories
1962—. Sandra G. Terrace:
B.S. (summa cum laude in Mathematics) 1975 Northeastern University Boston Massachusetts. Ms. Terrace works primarily from her home in Chelmsford Massachusetts where she and her husband own and operate a computer software consulting firm. She is a computer software consultant to the Acoustics Research Department of AT&T Bell Laboratories at Murray Hill New Jersey. Jay G. Wilpon:
B.S. and A.B. (cum laude) in Mathematics and Economics respectively 1977 Lafayette College Easton Pennsylvania M.S. (Electrical Engineering/Computer Science)
1982 Stevens Institute of Technology Hoboken N.J. AT&T Bell Laboratories
1977—.
Automatic speech recognition has advanced to the stage where it is now possible to recognize connected strings of words (e.g., digits, letters, city names, airline terms) from a word reference set of isolated tokens o...
Automatic speech recognition has advanced to the stage where it is now possible to recognize connected strings of words (e.g., digits, letters, city names, airline terms) from a word reference set of isolated tokens of each of the words in the vocabulary. Recently, an improved training technique called embedded word training was proposed, in which reference word patterns were extracted from within connected word sequences themselves. In this investigation we extend the embedded word training procedure to handle letters of the alphabet for use in a directory listing retrieval task. By performing connected letter recognition of spoken names based on letter classes (rather than specific letters themselves), we show how reliable name recognition results can be achieved using a fairly straightforward system on 200 randomly chosen names (chosen from an 18,210-name directory) spoken at a normal rate by four talkers (three male, one female) in a speaker-trained mode. We have found that an 8-percent improvement in name recognition accuracy is obtained when using embedded letter training patterns over that obtained from isolated letter patterns alone. The overall name recognition accuracy was close to 95 percent.
作者：
MENSH, dRThe Authorreceived his B.S. and M.S. degrees in applied physics from Loyola College in Baltimore
Md. and the American University in Washington D.C. He also has completed his course work towards his Ph.D. degree in computer science specializing in the fields of system analysis and computer simulation. He has been employed at the Naval Surface Weapons Center White Oak Laboratory Silver Spring Md. for the past seventeen years in the areas of weapon system analysis and the development of weapon system simulations. Since 1978 he has been involved in the development of simulation tools that can be applied to the solution of shipboard combat system architecture and engineering problems. Currently at the White Oak Laboratory he is responsible for the application of and further development of the Single Ship Combat System Simulation.
This paper will describe a combat system integration and analysis tool called the Ship Combat System Simulation (SCSS). The SCSS was designed as an analysis tool to study sensor command and control and weapon system i...
This paper will describe a combat system integration and analysis tool called the Ship Combat System Simulation (SCSS). The SCSS was designed as an analysis tool to study sensor command and control and weapon system integration for shipboard combat systems. The simulation represents the combat system components as nodes in a network. data flows between the nodes through the links. SCSS is a structuredprogram simulation written in Simscript II.5. The structuredprogram feature allows for ease of combat system reconfiguration into different types of architectures. Consequently, SSCS can be used to study and analyze different combat system architectures. Currently the model has an antiairwarfare (AAW) capability and a partial antisurface warfare (ASUW) capability. The model has been used in ship vulnerability and survivability studies, individual combat system component studies, component trade-off analysis; and total system reaction time analysis. Figure 1 presents a sample of a SCSS link-node diagram. Figures 8 and 9 present combat system sequence and timing diagrams. The model boasts a postprocessing capability that includes both statistics and graphics packages. The SCSS has been developed jointly by the Naval Weapons Center, Naval Ocean Systems Center, Naval Surface Weapons Center, Naval Ships Weapons Systems Engineering Station, and CACI, Inc. SCSS is supported by naval and industrial laboratories throughout the country. The users of the simulation belong to the SCSS User's Group which meets periodically throughout the year. Members of the User's Group develop equipment nodes and exchange ideas. The User's Group maintains SCSS configuration management allowing for Simscript II.5 code written by any one user to be used by all other users.
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