15,551 research outputs found
A knowledge-based decision support system for payload scheduling
This paper presents the development of a prototype Knowledge-based Decision Support System, currently under development, for scheduling payloads/experiments on space station missions. The DSS is being built on Symbolics, a Lisp machine, using KEE, a commercial knowledge engineering tool
Value of time, schedule delay and reliability - estimates based on choice behaviour of Dutch commuters facing congestion
This paper presents the results of a large stated choice experiment among Dutch commuters facing congestion. The experiment consisted of a fractional factorial design with 15 different attributes, three alternatives were car specific and the other was always public transport. Various model specifications have been estimated on the collected choice data allowing us to analyse choice behaviour of road users and determine their values of time, schedule delay (both late and early) and reliability (or uncertainty). In this paper we present the estimates of the best-fitting discrete choice models and interpret the results.
Linux Access Point and IPSec Bridge
[[abstract]]The main idea of this paper is to present an upper-layer security solution to solve security problems of the wireless network. The IEEE 802.11 standard defines the Wired Equivalent Privacy (WEP) Protocol. The goal of WEP is to provide data privacy to the wireless network. It is generally believed that the current wireless access points have a big security problem with WEP protocol. To solve this problem, a combination of Linux-based access point and IPSec bridge has been brought up to secure the wireless network.[[notice]]補正完畢[[journaltype]]國
LISP based simulation generators for modeling complex space processes
The development of a simulation assistant for modeling discrete event processes is presented. Included are an overview of the system, a description of the simulation generators, and a sample process generated using the simulation assistant
The relationships between illness perceptions, social support, coping on mood after first-time myocardial infarction
The aim of this study was to examine how illness perceptions, social support, and coping influence first-time MI patients' moods after six months post-MI. The second aim was to examine the roles of first-time MI couples' illness perceptions on their own moods. One hundred and twenty six first-time MI patients filled in the questionnaires during their hospitalisation, and 91 of them completed all three assessments during the first six months. Data from 42 first-time MI couples were also collected during the patients' hospitalisation. Thirty-five of the 42 MI couples completed all three assessments during the first six months. Therefore, information from 91 MI patients and 35 MI couples were used for longitudinal data analyses. The results indicated that when comparing with healthy people, first-time MI patients reported higher levels of depression, state anxiety and negative affect. Those held negative illness perceptions (e.g., worse illness consequences, longer recovery time, and worse symptom perception) tended to feel more depressed or anxious. Hierarchical regressions indicated that symptom perception and illness consequence perception were two important contributors of these MI patients' moods. In addition, some types of coping strategies and mood variables were also important. Data of MI couples indicated that spouses were also influenced by the MI event, and they reported higher levels of depression, state anxiety and negative affect. Those couples who both had negative illness perceptions of the MI tended to feel more negative. However, couples' moods did not significant correlate with each other. Hierarchical regression further showed only their own illness perceptions and moods significantly contributed to their own moods. Their partners' illness perceptions and moods did not contribute to their own moods. The finding suggested illness perceptions played important roles on MI patients' and spouses' moods. To improve moods, future studies should focus more on interventions of illness perceptions
Automatic programming of simulation models
The concepts of software engineering were used to improve the simulation modeling environment. Emphasis was placed on the application of an element of rapid prototyping, or automatic programming, to assist the modeler define the problem specification. Then, once the problem specification has been defined, an automatic code generator is used to write the simulation code. The following two domains were selected for evaluating the concepts of software engineering for discrete event simulation: manufacturing domain and a spacecraft countdown network sequence. The specific tasks were to: (1) define the software requirements for a graphical user interface to the Automatic Manufacturing Programming System (AMPS) system; (2) develop a graphical user interface for AMPS; and (3) compare the AMPS graphical interface with the AMPS interactive user interface
A study of microwave downcoverters operating in the K sub u band
A computer program for parametric amplifier design is developed with special emphasis on practical design considerations for microwave integrated circuit degenerate amplifiers. Precision measurement techniques are developed to obtain a more realistic varactor equivalent circuit. The existing theory of a parametric amplifier is modified to include the equivalent circuit, and microwave properties, such as loss characteristics and circuit discontinuities are investigated
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