Comprehension of spacecraft telemetry using hierarchical specifications of behavior ⋆

Abstract. A key challenge in operating remote spacecraft is that ground operators must rely on the limited visibility available through spacecraft telemetry in order to assess spacecraft health and operational status. We describe a tool for processing spacecraft telemetry that allows ground operators to impose structure on received telemetry in order to achieve a better comprehension of system state. A key element of our approach is the design of a domain-specific language that allows operators to express models of expected system behavior using partial specifications. The language allows behavior specifications with data fields, similar to other recent runtime verification systems. What is notable about our approach is the ability to develop hierarchical specifications of behavior. The language is implemented as an internal DSL in the Scala programming language that synthesizes rules from patterns of specification behavior. The rules are automatically applied to received telemetry and the inferred behaviors are available to ground operators using a visualization interface that makes it easier to understand and track spacecraft state. We describe initial results from applying our tool to telemetry received from the Curiosity rover currently roving the surface of Mars, where the visualizations are being used to trend subsystem behaviors, in order to identify potential problems before they happen. However, the technology is completely general and can be applied to any system that generates telemetry such as event logs.

Observations on the effects of a single-channel cochlear implant on a seven year old

This paper presents observations on the effects of a single-channel cochlear implant on a seven year-old hearing impaired child

2016 Alcohol Environmental Survey Report

During the month of September 2016, the Institute for Social and Behavioral Science (ISBS) located 216 establishments that sell alcoholic beverages in the east and west areas of Orange County, Florida. Our survey team operated within the boundaries of east and west Orange County, as established by Orange County Government (orangecountyfl.net). During the month of September 2016, the Institute for Social and Behavioral Science (ISBS) located 216 establishments that sell alcoholic beverages in the east and west areas of Orange County, Florida. Our survey team operated within the boundaries of east and west Orange County, as established by Orange County Government (orangecountyfl.net)

2016 Tobacco Environmental Survey Report

During the month of September 2016, the Institute for Social and Behavioral Science (ISBS) located 83 establishments that sell tobacco products in the west and south areas of Orange County, Florida. Our survey team operated within the boundaries of south and west Orange County, as established by the Orange County Government (orangecountyfl.net)

Compiling the language Balsa to delay insensitive hardware

A silicon compiler, Balsa-c, has been developed for the automatic synthesis of asynchronous, delay-insensitive circuits from the language Balsa. Balsa is derived from CSP with similar language constructs and a single-bit granularity type system. Balsa compiles to intermediate handshake circuits by an extended form of the com-pilation function used in the Tangram system.The handshake circuitsare subsequently mapped to CMOS implementations of 4-phase bundled-data asynchronous circuits by a suite of parameterised component-generating scripts within the Cadence design framework

Runtime verification of parametric properties using SMEDL

Parametric properties are typical properties to be checked in runtime verification (RV). As a common technique for parametric monitoring, trace slicing divides an execution trace into a set of sub traces which are checked against non-parametric base properties. An efficient trace slicing algorithm is implemented in MOP. Another RV technique, QEA further allows for nested use of universal and existential quantification over parameters. In this paper, we present a methodology for parametric monitoring using the RV framework SMEDL. Trace slicing algorithm in MOP can be expressed by execution of a set of SMEDL monitors. Moreover, the semantics of nested quantifiers is encoded by a hierarchy of monitors for aggregating verdicts of sub traces. Through case studies, we demonstrate that SMEDL provides a natural way to monitor parametric properties with more potentials for flexible deployment and optimizations

Tree Buffers

In runtime verification, the central problem is to decide if a given program execution violates a given property. In online runtime verification, a monitor observes a program’s execution as it happens. If the program being observed has hard real-time constraints, then the monitor inherits them. In the presence of hard real-time constraints it becomes a challenge to maintain enough information to produce error traces, should a property violation be observed. In this paper we introduce a data structure, called tree buffer, that solves this problem in the context of automata-based monitors: If the monitor itself respects hard real-time constraints, then enriching it by tree buffers makes it possible to provide error traces, which are essential for diagnosing defects. We show that tree buffers are also useful in other application domains. For example, they can be used to implement functionality of capturing groups in regular expressions. We prove optimal asymptotic bounds for our data structure, and validate them using empirical data from two sources: regular expression searching through Wikipedia, and runtime verification of execution traces obtained from the DaCapo test suite

Tube choledochoureterostomy: A simple method for bile diversion

A technique of bile diversion by tube choledochoureterostomy has been devised for the purpose of studying the role of bile in the intestinal absorption of drugs. This method was used in six dogs. No technical difficulties or major complications developed, as are inevitable with alternative methods, including external fistula. © 1990 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted

A Novel Run-Time Monitoring Architecture for Safe and Efficient Inline Monitoring

20th International Conference on Reliable Software Technologies - Ada-Europe 2015 (Ada-Europe 2015), Madrid, Spain.Verification and testing are two of the most costly and time consuming steps during the development of safety critical systems. The advent of complex and sometimes partially unpredictable computing architectures such as multicore commercial-of-the-shelf platforms, together with the composable development approach adopted in multiple industrial domains such as avionics and automotive, rendered the exhaustive testing of all situations that could potentially be encountered by the system once deployed on the field nearly impossible. Run-time verification (RV) is a promising solution to help accelerate the development of safety critical applications whilst maintaining the high degree of reliability required by such systems. RV adds monitors in the application, which check at run-time if the system is behaving according to predefined specifications. In case of deviations from the specifications during the runtime, safeguarding measures can be triggered in order to keep the system and its environment in a safe state, as well as potentially attempting to recover from the fault that caused the misbehaviour. Most of the state-of-the-art on RV essentially focused on the monitor generation, concentrating on the expressiveness of the specification language and its translation in correct-by-construction monitors. Few of them addressed the problem of designing an efficient and safe run-time monitoring (RM) architecture. Yet, RM is a key component for RV. The RM layer gathers information from the monitored application and transmits it to the monitors. Therefore, without an efficient and safe RM architecture, the whole RV system becomes useless, as its inputs and hence by extension its outputs cannot be trusted. In this paper, we discuss the design of a novel RM architecture suited to safety critical applications