An expert system for diagnosing environmentally induced spacecraft anomalies

A new rule-based, machine independent analytical tool was designed for diagnosing spacecraft anomalies using an expert system. Expert systems provide an effective method for saving knowledge, allow computers to sift through large amounts of data pinpointing significant parts, and most importantly, use heuristics in addition to algorithms, which allow approximate reasoning and inference and the ability to attack problems not rigidly defined. The knowledge base consists of over two-hundred (200) rules and provides links to historical and environmental databases. The environmental causes considered are bulk charging, single event upsets (SEU), surface charging, and total radiation dose. The system's driver translates forward chaining rules into a backward chaining sequence, prompting the user for information pertinent to the causes considered. The use of heuristics frees the user from searching through large amounts of irrelevant information and allows the user to input partial information (varying degrees of confidence in an answer) or 'unknown' to any question. The modularity of the expert system allows for easy updates and modifications. It not only provides scientists with needed risk analysis and confidence not found in algorithmic programs, but is also an effective learning tool, and the window implementation makes it very easy to use. The system currently runs on a Micro VAX II at Goddard Space Flight Center (GSFC). The inference engine used is NASA's C Language Integrated Production System (CLIPS)

An on-line expert system for diagnosing environmentally induced spacecraft anomalies using CLIPS

A new rule-based, expert system for diagnosing spacecraft anomalies is under development. The knowledge base consists of over two-hundred rules and provide links to historical and environmental databases. Environmental causes considered are bulk charging, single event upsets (SEU), surface charging, and total radiation dose. The system's driver translates forward chaining rules into a backward chaining sequence, prompting the user for information pertinent to the causes considered. The use of heuristics frees the user from searching through large amounts of irrelevant information (varying degrees of confidence in an answer) or 'unknown' to any question. The expert system not only provides scientists with needed risk analysis and confidence estimates not available in standard numerical models or databases, but it is also an effective learning tool. In addition, the architecture of the expert system allows easy additions to the knowledge base and the database. For example, new frames concerning orbital debris and ionospheric scintillation are being considered. The system currently runs on a MicroVAX and uses the C Language Integrated Production System (CLIPS)

Diagnosing anomalies of spacecraft for space maintenance and servicing

Very often servicing of satellites is necessary to replace components which are responsible for anomalous behavior of satellite operations due to adverse interactions with the natural space environment. A major difficulty with this diagnosis is that those responsible for diagnosing these anomalies do not have the tools to assess the role of the space environment causing the anomaly. To address this issue, we have under development a new rule-based, expert system for diagnosing spacecraft anomalies. The knowledge base consists of over two-hundred rules and provides links to historical and environmental databases. Environmental causes considered are bulk charging, single event upsets (SEU), surface charging, and total radiation dose. The system's driver translates forward chaining rules into a backward chaining sequence, prompting the user for information pertinent to the causes considered. When the user selects the novice mode, the system automatically gives detailed explanations and descriptions of terms and reasoning as the session progresses, in a sense teaching the user. As such it is an effective tutoring tool. The use of heuristics frees the user from searching through large amounts of irrelevant information and allows the user to input partial information (varying degrees of confidence in an answer) or 'unknown' to any question. The system is available on-line and uses C Language Integrated Production System (CLIPS), an expert shell developed by the NASA Johnson Space Center AI Laboratory in Houston

Predicting Solar Cycle 24 and beyond

We use a model for sunspot number using low-frequency solar oscillations, with periods 22, 53, 88, 106, 213, and 420 years modulating the 11-year Schwabe cycle, to predict the peak sunspot number of cycle 24 and for future cycles, including the period around 2100 A.D. We extend the earlier work of Damon and Jirikowic (1992) by adding a further long-period component of 420 years. Typically, the standard deviation between the model and the peak sunspot number in each solar cycle from 1750 to 1970 is ±34. The peak sunspot prediction for cycles 21, 22, and 23 agree with the observed sunspot activity levels within the error estimate. Our peak sunspot prediction for cycle 24 is significantly smaller than cycle 23, with peak sunspot numbers predicted to be 42 ± 34. These predictions suggest that a period of quiet solar activity is expected, lasting until ∼2030, with less disruption to satellite orbits, satellite lifetimes, and power distribution grids and lower risk of spacecraft failures and radiation dose to astronauts. Our model also predicts a recovery during the middle of the century to more typical solar activity cycles with peak sunspot numbers around 120. Eventually, the superposition of the minimum phase of the 105- and 420-year cycles just after 2100 leads to another period of significantly quieter solar conditions. This lends some support to the prediction of low solar activity in 2100 made by Clilverd et al. (2003)

Results of the 2014 Eagle Marsh Biodiversity Survey, Allen County, Indiana

ABSTRACT. Eagle Marsh, a 289.8 ha (716-acre) wetland nature preserve located on the southwest border of Fort Wayne, Indiana, is one of the largest wetland restorations ever undertaken in Indiana. The Little River Wetlands Project (LRWP) began acquisition, planning, and restoration in 2005 to 2007. The first biodiversity survey (also known as a bioblitz) of Eagle Marsh was conducted on 31 May and 1 June 2014. Over 125 scientists, naturalists, students, and other volunteers on thirteen different taxonomic teams observed and reported 728 taxa during the event. The thirteen taxonomic teams included aquatic macroinvertebrates, beetles, birds, butterflies, dragonflies and damselflies, fish, freshwater mussels, herpetofauna, small mammals, mushrooms/fungi, singing insects, snail-killing flies, and vascular plants. This manuscript presents both a brief history of Eagle Marsh and a summary overview of the results gathered by the thirteen taxonomic teams

Editorial: Who Is Afraid to Give Freedom of Speech to Marketing Folks?

Despite the invaluable contribution of marketing folks (e.g., making markets work), they fail to enjoy the same freedom of speech as others. This fact is particularly egregious because unlike other groups that can use threats, force, or coercion, marketing folks rely only on speech. Although the U.S. Constitution never mentions commercial speech, the courts invented the concept to censor marketing folks. The cloudy rational was that consumers need special protection from marketing folks (e.g., advertising). Naturally, censorship leads to abuse. Powerful incumbents use censorship covertly against new entrants. Politicians use censorship surreptitiously to promote their own political goals. If consumers need protection, it is certainly from the misleading statements of those with freedom of speech—politicians, attorneys, the news media, and the censors.freedom of speech, commercial speech, censorship, advertising, marketing, regulation, branding

Effect of poloxamer 188 vs placebo on painful vaso-occlusive episodes in children and adults with sickle cell disease : a randomized clinical trial

Key PointsQuestionCan poloxamer 188, an agent that is reported to reduce blood viscosity and cell-cell interactions, effectively reduce the duration of vaso-occlusive episodes (painful crises) in hospitalized patients with sickle cell disease? FindingsIn this randomized clinical trial that included 388 children and adults with sickle cell disease, treatment with poloxamer 188 vs placebo resulted in mean time to last dose of parenteral opioids during vaso-occlusive episodes of 81.8 vs 77.8 hours, a difference that was not statistically significant. MeaningAmong patients with sickle cell disease, poloxamer 188 did not significantly shorten the duration of painful vaso-occlusive episodes