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tHE NEXt-GENERAtION IN UNDERWAtER ACOUStIC DEtECtION

at&t tECHNICAL JOURNAL 1995年第4期74卷 4-15页

作者： EICKMEYER, JR EPtING, BE tHOMPSON, MV Undersea Systems Engineering Department at AT&T Advanced Technology Systems in Whippany New Jersey Fixed Distributed System-Underwater Segment (FDS-UWS) program at AT&T Advanced Technology Systems in Greensboro North Carolina Undersea Systems Engineering Department at AT&T Bell Laboratories in Whippany New Jersey

Since the 1950s, At&t has provided underwater detection equipment to the U.S. Navy to satisfy the navy's two-tier mission of studying the ocean and developing and testing sonar systems. the latest generation o... 详细信息

Since the 1950s, at&t has provided underwater detection equipment to the U.S. Navy to satisfy the navy's two-tier mission of studying the ocean and developing and testing sonar systems. the latest generation of hardware is a fiber-optic system that has the transmission capacity of all the previous systems combined. Its design and development has provided a challenge both from the technical aspect of meeting stringent performance requirements and from the engineering aspect of managing a large defense program having a budget greater than $500 million. Following a brief summary of at&t's history in the development and manufacture of underwater acoustic detection hardware, this paper provides a technical description of the fiber-optic system and a project history describing the processes used in bringing the equipment into production. During the period of program execution (1989 to the present), systems engineering management philosophy has evolved from strict now-down of requirements via military standards to concurrent engineering and product-realization teams. the Fixed Distributed System (FDS) project has followed the same route, partly by design and partly by necessity. It provided some valuable lessons that have been learned and incorporated into the present at&t advanced technology systems (AtS) engineering process, which has been the basis for at&t Best Current Practices in systems engineering.

关键词： Underwater acoustics

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2.2.4 On the Diversity of Process Metrics Users: Identification of Metrics types and Other Attributes

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INCOSE International Symposium 1995年第1期5卷 609-617页

作者： Martin, James N. Undersea Systems Engineering Department AT&T Advanced Technology Systems 67 Whippany Road WhippanyNJ07981 United States

this paper explores the relationship between process metrics users and their diverse needs. twenty metrics user classes and nine basic metrics types are identified. Other attributes of metrics are defined. these metrics types are correlated to the different user classes with regard to their degree of usefulness to each user class. Other attributes such as data tempo, data level of detail and data type are identified for each user class. three categories of correlation factors are identified that can be used by the metrics analyst and users: normalization factors, quality correlation factors, and cost estimating relationship factors. the degree of usefulness of each correlation factor for the user classes is also identified. © 1995 the Authors.

关键词： Cost estimating

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6.2.2 Re-engineering of the Metrics Collection Process

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INCOSE International Symposium 1995年第1期5卷 625-633页

作者： Martin, James N. Miller, William D. Undersea Systems Engineering Department AT&T Advanced Technology Systems 67 Whippany Road WhippanyNJ07981 United States

this paper describes the re-engineered process for metrics collection in the advanced technology systems sector of At&t. the previous process was cumbersome for both the metrics data collector and the metrics anal... 详细信息

this paper describes the re-engineered process for metrics collection in the advanced technology systems sector of at&t. the previous process was cumbersome for both the metrics data collector and the metrics analyst. Much of the data collected was unusable. the collectors of metrics were frustrated since they spent many hours hunting for the data and it was often difficult to obtain. therefore, much of the data the metrics analyst needed to do his job was not available. Hence, our major criteria for re-engineering the process was to simplify the metrics data forms, to minimize the amount of work to be done by the data collector. the major advance was to collect existing cost and schedule data directly from the financial management system (FMS) instead of asking the metrics data collector to provide this. to do this, we developed a means to collect data using an "extraction map" to locate the existing cost/schedule data from the FMS. the new metrics data forms are described along with the streamlined collection and analysis process. © 1995 the Authors.

关键词： Reengineering

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5.3.3 Requirements Mythology: Shattering Myths About Requirements and the Management thereof

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INCOSE International Symposium 1995年第1期5卷 503-512页

作者： Martin, James N. Undersea Systems Engineering Department AT&T Advanced Technology Systems 67 Whippany Road Room 3C-212 WhippanyNJ07981 United States

Requirements cannot be managed well if the true nature of these requirements is not understood. there are some misperceptions about requirements that lead to improper application of requirements practices and principles. For example, some believe that "all requirements must be verifiable" before they can be declared to be "good" requirements. If this were true, then we would have to ignore the "non-good" requirements we often get from our customer and potential system users who are not usually literate enough in "requirements engineering" to give us verifiable requirements per se. In fact, the customer usually can tell you if a requirement is met "when they see it." A more accurate statement is that all specified requirements must be verifiable. this is not an insignificant distinction. this example illustrates the danger of believing in certain "requirements myths". Like all mythology, each particular myth has a degree of truth in it. It is this element of truth that encourages the persistence of these myths. It would be better to apply these truths to a better understanding of requirements management principles and application of its practices. this paper describes a dozen common myths about requirements. Each myth is examined to determine the true and the false elements and to identify the traps to avoid when performing requirements engineering tasks. © 1995 the Authors.

关键词： Requirements engineering

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the PMtE Paradigm: Exploring the Relationship Between systems engineering Process and tools

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INCOSE International Symposium 1994年第1期4卷 176-183页

作者： Martin, James N. Undersea Systems Engineering Department AT&T Advanced Technology Systems 67 Whippany Road Room 3C-212 WhippanyNJ07981 United States

this paper explores the relationship between process and tools for systems engineering. there is much interest now in process maturity, yet there are many cases of processes being developed and deployed with little effect on the bottom line. In fact, there are times when the overall health of the engineering organization is not improved with the use of standardized processes and tools. It is important to have a proper balance among process, methods, tools, and environment (PMtE) when performing systems engineering (SE) tasks. An improper balance leads to increased costs and lower quality, in addition to frustration for engineers and for management. the particular PMtE elements appropriate for a project should be defined and documented in an SE Development Environment (SEDE) Plan which can cover the gaps in a project SE Management Plan (SEMP). this paper proposes a paradigm for understanding the PMtE elements for systems engineering. © 1994 the Authors.

关键词： Professional aspects

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A Process for systems engineering Planning

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INCOSE International Symposium 1994年第1期4卷 688-695页

作者： Martin, James N. Undersea Systems Engineering AT&T Advanced Technology Systems 67 Whippany Road Room 3C-212 WhippanyNJ07981 United States

this paper describes the systems engineering Planning process used in At&t advanced technology systems. A process diagram is shown with 19 specific process tasks. Each of these process tasks are defined. In additi... 详细信息

this paper describes the systems engineering Planning process used in at&t advanced technology systems. A process diagram is shown with 19 specific process tasks. Each of these process tasks are defined. In addition, inputs and outputs from each process task are defined. this process is intended to be used at the beginning of each project and the major output is a systems engineering Management Plan (SEMP). Other outputs are the systems engineering Master Schedule (SEMS), systems engineering Detailed Schedule (SEDS), and a systems engineering Development Environment (SEDE) Plan. © 1994 the Authors.

关键词： Project management

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On the statistics of the companding noise in t1 carrier systems

On the statistics of the companding noise in T1 carrier syst...

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IEEE International Conference on Communications (ICC)

作者： J. Davidson I. Kalet Department of Electrical Engineering-Systems Tel-Aviv University Israel On Sabbatical Leave at AT&T Bell Laboratories Advanced Wireless Technology Laboratory Whippany NJ USA

In modern voiceband data communication using t1 carrier systems, the received signal is subject to nonlinear quantization noise due to companding. In order to design better signal constellations for this environment, it is of interest to characterize this noise. An analytical expression for the probability density function (PDF) of the nonlinear quantization noise and a numerical result for the PDF of the filtered noise, which is the actual noise at the slicer input of the linear receiver, are obtained. the results are compared to a Gaussian PDF. It is concluded that a Gaussian approximation, although not entirely accurate, is not unreasonable.< >

关键词： Statistics Working environment noise Quantization Noise figure Modems Degradation Additive noise Signal design Constellation diagram Probability density function

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AN ALGORItHM FOR SIZING tRUNKS CARRYING MIXtURES OF CONStANt AND VARIABLE BIt-RAtE tRAFFIC

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INtERNAtIONAL JOURNAL OF COMMUNICAtION systems 1995年第5期8卷 313-323页

作者： REGE, KM AT&T Bell Laboratories Room 3m-324 Holmdel New Jersey 07733 U.S.A. Kiran M. Rege is with the Performance Analysis Department of AT&T Bell Laboratories Holmdel New Jersey. He received his bachelor's degree from the Indian Institute of Technology Bombay in 1977 an M.E. from the University of Florida Gainesville in 1979 and a Ph.D. from the University of Hawaii Honolulu in 1981 all in Electrical Engineering. Besides working at AT&T Bell Laboratories he has spent a year teaching at I.I.T. Bombay and has worked with the Centre for Development of Advanced Computing Pune India. His research interests include performance modelling and analysis techniques queueing theory communication systems and natural language processing.

As new broadband networks based on the asynchronous transfer mode (AtM) protocol emerge to support a variety of services, the need for analytical models and tools for sizing network components carrying mixtures of different kinds of traffic will be increasingly felt. this paper presents a simple, yet efficient algorithm for sizing trunks carrying mixtures of constant and variable bit rate traffic. It combines theoretical results for the multi-dimensional Erlang model and the concept of equivalent bandwidth with some heuristic arguments to produce an analytic method for sizing trunks subject to blocking and quality of service constraints for traffic classes.

关键词： AtM ERLANG BLOCKING EQUIVALENt BANDWIDtH BROAD-BAND NEtWORKS

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Jackknifed variance estimators for simulation output analysis 15

Jackknifed variance estimators for simulation output analysi...

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Simulation Winter Conference

作者： Kemal Dinçer Dingeç Christos Alexopoulos David Goldsman James R. Wilson Wenchi Chiu tûba Aktaran-Kalaycı H. Milton Stewart School of Industrial and Systems Engineering Georgia Institute of Technology Atlanta GA USA Edward P. Fitts Department of Industrial and Systems Engineering North Carolina State University Raleigh NC USA Fenxi LLC Belmont CA USA AT&T Advanced Analytics Big Data Atlanta GA USA

ISBN: (纸本)9781467397414

We develop new point estimators for the variance parameter of a steady-state simulation process. the estimators are based on jackknifed versions of nonoverlapping batch means, overlapping batch means, and standardized time series variance estimators. the new estimators have reduced bias-and can be manipulated to reduce their variance and mean-squared error-compared with their predecessors, facts which we demonstrate analytically and empirically.

关键词： time series analysis Steady-state Analytical models Mathematical model Random variables

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