The development of an intelligent user interface for NASA's scientific databases

The National Space Science Data Center (NSSDC) has initiated an Intelligent Data Management (IDM) research effort which has as one of its components, the development of an Intelligent User Interface (IUI). The intent of the IUI effort is to develop a friendly and intelligent user interface service that is based on expert systems and natural language processing technologies. This paper presents the design concepts, development approach and evaluation of performance of a prototype Intelligent User Interface Subsystem (IUIS) supporting an operational database.     

A prototype expert system in OPS5 for data error detection

A prototype expert system has been developed in the OPS5 language to perform error checking on data which spacecraft builders/users supply to the NASA Goddard Space Flight Center for processing on the Communications Link Analysis and Simulation System (CLASS) computer. This prototype expert system, called Trajectory Preprocessing System (TRAPS), contains 49 rules and at present runs on an IBM PC in the OPS5+ software package from Artelligence, Inc. In its operational phase, TRAPS will run in the Oak Ridge Production Language (ORPL) on the CLASS computer (a Perkin-Elmer 3244 supermini). ORPL, an implementation of OPS5 by the Oak Ridge National Laboratory in MULTIFORTH on a Hewlett-Packard 9836 desktop computer, is now being ported to SS-FORTH on the CLASS computer. This paper discusses the expert system problem domain, development approach, tools, results and future plans stemming from the TRAPS project.     

Development of an expert system prototype for determining software functional requirements for command management activities at NASA goddard

At NASA Goddard, the role of the command management system (CMS) is to transform general requests for spacecraft operations into detailed operational plans to be uplinked to the spacecraft. The CMS is part of the NASA Data System which entails the downlink of science and engineering data from NASA near-earth satellites to the user, and the uplink of command and control data to the spacecraft. Presently, it takes one to three years, with meetings once or twice a week, to determine functional requirements for CMS software design. As an alternative approach to the present technique of developing CMS software functional requirements, an expert system prototype was developed to aid in this function. Specifically, the knowledge base was formulated through interactions with domain experts, and was then linked to an existing expert system application generator called “Knowledge Engineering System.” Knowledge base development focused on four major steps: (1) develop the problem-oriented attribute hierarchy; (2) determine the knowledge management approach; (3) encode the knowledge base; and (4) validate, test, certify, and evaluate the knowledge base and the expert system prototype as a whole. Backcasting was accomplished for validating and testing the expert system prototype. Knowledge refinement, evaluation, and implementation procedures of the expert system prototype were then transacted.     

A unified approach for on-line performance evaluation of CCNs

The primary trade-off in a large computer-communication network (CCN) is the balance between computation processing capability and communication capability. Essentially, a CCN model should utilize operational optimization (rather than mathematical optimization) allowing the user (mostly a non-programme network expert) to call upon his experience and insight in dealing with real-life networks to decide upon proper direction for modifications. We propose, in this paper, a unified approach which will hopefully allow an on-line user to make real-time modifications to CCNs to obtain operationally optimal system trade-offs in such areas as network overall reliability, communication response, computation response, and optimum channel capacities etc.     

Empirical relationship between communication costs and the channel bit rate for large computer networks

The primary trade-off in a large computer-communication network (CCN) is the balance between computation processing capability and communication capability. Essentially, a CCN model should utilize operational optimization (rather than mathematical optimization) allowing the user (mostly a non-programme network expert) to call upon his experience and insight in dealing with real-life networks to decide upon proper direction for modifications. We propose, in this paper, a unified approach which will hopefully allow an on-line user to make real-time modifications to CCNs to obtain operationally optimal system trade-offs in such areas as network overall reliability, communication response, computation response, and optimum channel capacities etc.     

Software project management under incomplete and ambiguousspecifications

It is noted that large system development and government contracts still adhere to a classical life-cycle approach to software development. A major problem in the classical approach is the completeness and clarity of the user requirements. Some author shave suggested that alternative paradigms are more timely. One such paradigm is the use of prototype software models. The author believes that prototyping is an appropriate approach that can be used as a significant feature of the more formal life-cycle process, with little overall reduction in project control. He explores three aspects of such a development process. First, the underlying assumptions and the evolution of the current life-cycle management control method are discussed. The differing perspectives of the software designer and the user are discussed. A conceptual framework that graphically portrays this difference is proposed. Second, requirements are assumed to be ambiguous and incomplete. The contents of a requirements document are discussed with the perspective that requirements will always be incomplete until late in the development cycle. Third, prototyping activities have a primary objective of reducing ambiguity. Different prototyping strategies are appropriate for different phases of the development cycle. An altered life cycle (which includes prototyping as a format part of the process) is used to trace the evolution of the requirements document from an ambiguous objective to a system reference document     

Automated space vehicle control for rendezvous proximity operations

Rendezvous during the unmanned space exploration missions, such as a Mars Rover/Sample Return, will require a completely automatic system from liftoff to docking. A conceptual design of an automated rendezvous, proximity operations, and docking system is being implemented and validated at the Johnson Space Center (JSC).The emphasis of this article is on the progress of the development and testing of a prototype system for control of the rendezvous vehicle during proximity operations that is currently being developed at the JSC. Fuzzy sets are used to model the human capability of common sense reasoning in decision-making tasks and such models are integrated with expert systems and engineering control system technology to create a system that performs comparably to a manned system.     

MAPCON: an expert system for configuration of MAP networks

The MAPCON (MAP configuration) system is a knowledge-based tool used to configure MAP (manufacturing automation protocol) version 2.1 networks. Configuration management deals with determining the characteristics of the network and setting the parameters of the devices attached to the network in such a way as to make the network operational. MAPCON performs static configuration and can be used for reconfiguration purposes in an offline mode. MAPCON does not interface to the network and hence does not interact with the operational network. The parameters that are considered are the ones required for MAP 2.1 networks. The rules for identifying values of these parameters are developed and implemented. The MAPCON expert system was built entirely in Knowledge Craft, a language and development environment for building expert systems on the TI Explorer Lisp machine. Knowledge for the MAPCON expert system was obtained through interviews with MAP experts. This knowledge was then organized and implemented in Knowledge Craft. In addition, an elegant user interface was developed for the system     

NASA ground terminal communication equipment: Automated fault isolation expert systems

This paper describes the prototype expert systems that diagnose the Distribution and Switching System I and II (DSS1 and DSS2), Statistical Multiplexers (SM), and Multiplexer and Demultiplexer systems (MDM) at the NASA Ground Terminal (NGT) located at White Sands, New Mexico. A system-level fault isolation expert system monitors the activities of a selected data stream, verifies that the fault exists in the NGT and identifies the faulty equipment. Equipment-level fault isolation expert systems will be invoked to isolate the fault to a Line Replaceable Unit (LRU) level. Input and sometimes output data stream activities for the equipment are available. The system-level fault isolation expert system will compare the equipment input and output status for a data stream and perform loopback tests (if necessary) to isolate the faulty equipment. The equipment-level fault isolation system utilizes the process of elimination and/or the maintenance personnel's fault isolation experience stored in its knowledge base. The DSS1, DSS2, and SM fault isolation systems, using the knowledge of the current equipment configuration and the equipment circuitry, will issue a set of test connections according to the predefined rules. The faulty component or board can be identified by the expert system by analyzing the test results. The MDM fault isolation system correlates the failure symptoms with the faulty component based on maintenance personnel experience. The faulty component can be determined by knowing the failure symptoms.

The NGT fault isolation prototype is implemented in Prolog, C, and VP-Expert, on an IBM AT compatible workstation. The DSS1, DSS2, SM, and MDM equipment simulators are implemented in PASCAL. The equipment simulator receives connection commands and responds with status for the expert system according to the assigned faulty component in the equipment. The DSS1 fault isolation expert system was converted to C language from VP-Expert and integrated into the NGT automation software for offline switch diagnoses.

Potentially, the NGT fault isolation algorithms can be used for the DSS1, SM, and MDM located at Goddard Space Flight Center (GSFC). The prototype could be a training tool for the NGT and NASA Communications (Nascom) Network maintenance personnel.     

A reliability model for real-time rule-based expert systems

This paper uses two modeling tools to analyze the reliability of real-time expert systems: (1) a stochastic Petri net (SPN) for computing the conditional response time distribution given that a fixed number of expert system match-select-act cycles are executed, and (2) a simulation search tree for computing the distribution of expert system match-select-act cycles for formulating a control strategy in response to external events. By modeling the intrinsic match-select-act cycle of expert systems and associating rewards rates with markings of the SPN, the response time distribution for the expert system to reach a decision can be computed as a function of design parameters, thereby facilitating the assessment of reliability of expert systems in the presence of real-time constraints. The utility of the reliability model is illustrated with an expert system characterized by a set of design conditions under a real-time constraint. This reliability model allows the system designers to: (1) experiment with a range of selected parameter values; and (2) observe their effects on system reliability     

Communications for the digitized battlefield of the 21st century

Technology base investments by the US Army will exploit the wealth of emerging commercial telecommunications services, as an operational supplement to classical tactical communications systems. This paper presents a series of technology components that collectively form the basis for the Army's Battlefield Information Transmission System and will provide the underlying seamless, global, “ubiquitous” transmission system for the Force XXI warfighter. The technical and system architectures of the 21st century will evolve through a gradual process of development, acquisition, and experimentation. This process, by definition, is a combined effort relying on the Army Materiel Command (AMC) Research, Development and Engineering Center (RDECs) working with the TRADOC battlelabs. The battlelabs, through a formal series of Advanced Warfighting Experiments (AWEs), play a crucial role in testing and adapting the technology produced by the AMC RDECs and commercial providers. Commercial technology is also directly exploited in TRADOC user environments as part of the Army's ACT II program     

An Expert System for Remote Sensing

The Canada Centre for Remote Sensing has developed two hierarchical expert systems, the Analyst Advisor and the Map Image Congruency Evaluation (MICE) advisor. These expert systems are built upon our Remote-Sensing Shell (RESHELL) written in Logicware's MPROLOG. A shell is a programming environment that specifically caters to expert system development. Knowledge is represented in the production rules and frames database. Numerical processing takes place using the extensive FORTRAN code of the Landsat Digital Image Analysis System (LDIAS). The LDIAS includes several DEC VAX computers, image displays, specialized processors, and DEC Al VAXstations. The paper describes the architecture of the expert system to compare maps and images (MICE) and the expert system to advise on the extraction of resource information from remotely sensed data, the Analyst Advisor. Details are given concerning the structure of RESHELL and our methods of interfacing symbolic reasoning in PROLOG on the Al VAX stations with numeric processing in FORTRAN on several different computers. The first prototype of the Analyst Advisor will be released for internal use at CCRS in March 1987.     

动态代码的实时可信传递研究

 基于可信计算技术的恶意代码防范机制可以弥补传统杀毒方式对未知恶意代码防范能力的不足,但是软件自动在线升级和补丁安装会生成和调用未知的动态代码,对这些动态代码的实时可信判定问题阻碍了可信计算技术的应用普及.动态代码实时可信判定和可信传递方法(Trust Determination and Transitivity Method of Dynamic codes,TDTMD)从代码的调用环境和调用方式出发,对动态代码的来源是否可信进行判定,进而对动态代码是否可信进行判断.TDTMD可以在保证应用软件和系统的运行连续性前提下,提供对各种已知或未知恶意代码攻击的有效防范能力.TDTMD的原型系统及其实验结果表明,它对系统的运行性能影响较小,并且安全有效.     

Modular Wireless Real-Time Sensor/Actuator Network for Factory Automation Applications

Modern factory facilities are characterized by highly flexible manufacturing cells and highly dynamic processes, where clusters of fixed or moving sensors and actuators have to be controlled in a limited space under stringent real-time and reliability constraints. In such demanding industrial environments, wireless systems can also be beneficial by improving flexibility, cutting cables, and enabling solutions, which are cumbersome or even not possible to realize with wireline systems, especially in controlling moving or rotating parts. In this paper, we present a conceptual study of a wireless real-time system dedicated for remote sensor/actuator control in production automation. System development is based on user requirements, which were extracted from customer interviews and a market research. Low level measurements of frequency- and space-selective wireless channels in a factory-like environment were carried out. System design aspects, i.e., network topology, multiple access schemes, and radio technologies, will be thoroughly reviewed. The performance of a first prototype implementation will be discussed with emphasis on timing behavior and power consumption, as sensors and actuators of the wireless system are intended to operate without power lines or batteries     

Low Complexity On-Line Adaptation Techniques in Context of Assamese Spoken Query System

In this work, we present the development of an Assamese spoken query (SQ) system for accessing the price of agricultural commodities. The developed system intends to make the cultivators aware of the recent market trends. The SQ system enables the user to access the latest price of the commodity by calling the system using a landline/mobile phone. The spoken query input by the user is processed and then current price of the desired commodity in the given district is played back by the system. Features that make the system user friendly are incorporated into the design after taking feedbacks from local farmers. In other words, the system is tuned as per the needs of the users. Furthermore, the issues of adapting such query systems to the end user are also explored in this work. In case of the developed SQ system, the typical user responses are of extremely small duration (1–2 seconds due to isolated word response from the user). Moreover, the employed adaptation approach must keep the system latency low since these systems are meant for real-time applications. Consequently, adapting such systems to the end user becomes an extremely challenging task. In this regard, acoustic model interpolation based adaptation techniques are proposed that employ interpolation weights derived in an approximate fashion. The proposed approaches try to minimize the latency in the system response by avoiding the iterative weight estimation procedure used in the earlier reported works. Even with extremely small amount of adaptation data, the proposed approaches are found to result in a relative improvement of 12 % over the baseline ASR system.     

Pigeon: a wireless two-way messaging system

Wireless messaging is an integral component of universal personal communication services (PCSs). Its growth is likely to be further fueled by the availability of new data capabilities in the new PCS air interfaces. Our research focuses on high-level issues such as new messaging functionalities, high-layer protocols, and overall system design. Pigeon is our proposal of a wireless two-way messaging system. The novelty of our system lies in: (1) the techniques used in mitigating the wireless media and end device constraints, (2) the functionalities provided, and (3) its modular architecture. Examples of (1) include the use of asymmetric protocols and the introduction of user agents. Examples of (2) include group addressing, transaction support, and flexible messages. The modularity of Pigeon allows its individual components to be adopted by specific systems, A prototype of Pigeon has been implemented, and is operational at Bell Laboratories. We describe the motivation, design, and functionality of Pigeon. We also present, as an example, a mapping of Pigeon to a standard cellular/PCS messaging system     

Performance evaluation of eventing web services in real-time applications

The objective of this research is to study the application of Web services technology in distributed real-time data delivery systems, as well as to determine the appropriate contexts in which such a design can be considered. We focus on distributed real-time systems and more specifically, on distributed soft real-time systems, which stand to benefit most from the use of Web services technology. We provide a means to evaluate the inclusion of Web services-based middleware in real-time system design. The decision to use the standardized data representation and communications protocols of Web services can bring tremendous value and benefit to both the service provider and the end user of a real-time system; however, the temporal performance of such systems is a critical factor. This research examines the most significant general performance considerations applicable to such systems and more specifically, provides a model to be used in the determination of whether a given system configuration can meet a specific soft real-time performance target.     

Direction finding and “smart antennas” using softwareradio architectures

Operational tests and demonstrations of systems based on software radios are currently being performed in the 800 MHz mobile cellular radio band. These field trials are for mobile unit geolocation systems and adaptive phased array “smart antenna” applications. The geolocation system trials are in response to the demand for high confidence geolocation of mobile units for enhanced emergency 911 service and for use in the US Department of Transportation's Intelligent Vehicle Highway System (NHS) initiative. The smart antenna array application addresses the cellular service providers' need for more user channel capacity and/or geographic coverage from existing base station installations. Software radio architectures were selected because of their ability to provide superior performance at low life cycle cost. These systems use 4 to 8 wideband coherent channels and fully characterize the arriving RF energy to either geolocate the emitter or to maximize the carrier-to-interference ratio