271 research outputs found

    READ @your library James Bret Michael (bookmark)

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    A project of the Dudley Knox Library at the Naval Postgraduate School

    A framework for computer-aided validation

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    This paper presents a framework to incorporate computer-based validation techniques to the independent validation and verification (IV&V) of software systems. The framework allows the IV&V team to capture its own understanding of the problem and the expected behavior of any proposed system for solving the problem via an executable system reference model, which uses formal assertions to specify mission- and safety-critical behaviors. The framework uses execution-based model checking to validate the correctness of the assertions and to verify the correctness and adequacy of the system under test.Approved for public release; distribution is unlimited

    Formal Verification of Cyberphysical Systems

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    17 USC 105 interim-entered record; under review.Computer hosts a virtual roundtable with seven experts to discuss the formal specification and verification of cyberphysical systems.http://hdl.handle.net/10945/6944

    Developing highly predictable system behavior in real-time battle-management software

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    Given that battle-management solutions in system-of-systems environment are separately designed and developed on various operating platforms in different languages, predicting battle-management behavior of system-of-systems is not possible. As a rule, battle-management is executed at the system level rather than the desired system-of-systems level. Typically, C4 systems are non-real-time systems. Traditionally, weapon systems are real-time systems. If we are to match the performance of weapon systems and avoid the negative impact of forcing synchronization of battle manager software with weapon systems for messaging, then we must develop the battle manager as real-time software. We advocate the development of battle-management software as a real-time set of system functionality that addresses warfighter usage. To achieve the level of desired predictable battle-management behavior, we maintain that it is essential to develop a formal representation that captures the desired battle manager system behavior and test the formal representation against the expected battle-management properties. Furthermore, we assert that it is critical to develop the battle manager as a real-time software-intensive system to ensure the schedulability of battlemanagement tasks and provide for concurrent execution of such tasks where applicable.Approved for public release; distribution is unlimited

    Music For the Holidays

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    Braden Auditorium Sunday Evening November 24, 1991 7:00p.m

    Behavioral strategies during incubation influence nest and female survival of Wild Turkeys

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    Females must balance physiological and behavioral demands of producing offspring with associated expenditures, such as resource acquisition and predator avoidance. Nest success is an important parameter underlying avian population dynamics. Galliforms are particularly susceptible to low nest success due to exposure of ground nests to multiple predator guilds, lengthy incubation periods, and substantive reliance on crypsis for survival. Hence, it is plausible that nesting individuals prioritize productivity and survival differently, resulting in a gradient of reproductive strategies. Fine-scale movement patterns during incubation are not well documented in ground-nesting birds, and the influence of reproductive movements on survival is largely unknown. Using GPS data collected from female wild turkeys (n = 278) across the southeastern United States, we evaluated the influence of incubation recess behaviors on trade-offs between nest and female survival. We quantified daily recess behaviors including recess duration, recess frequency, total distance traveled, and incubation range size for each nest attempt as well as covariates for nest concealment, nest attempt, and nest age. Of 374 nests, 91 (24%) hatched and 39 (14%) females were depredated during incubation. Average nest survival during the incubation period was 0.19, whereas average female survival was 0.78. On average, females took 1.6 daily unique recesses (SD = 1.2), spent 2.1 hr off the nest each day (SD = 1.8), and traveled 357.6 m during recesses (SD = 396.6). Average nest concealment was 92.5 cm (SD = 47). We found that females who took longer recess bouts had higher individual survival, but had increased nest loss. Females who recessed more frequently had lower individual survival. Our findings suggest behavioral decisions made during incubation represent life-history trade-offs between predation risk and reproductive success on an unpredictable landscape

    Development and piloting of an exposure database and surveillance system for DOE cleanup operations

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    An industrial hygiene exposure database and surveillance system was developed in partnership between National Institute for Occupational Safety and Health (NIOSH)-funded independent investigators and practicing industrial hygienists at the Rocky Flats Environmental Technology Site (RFETS) in Golden, Colo. RFETS is a former U.S. Department of Energy nuclear weapons plant that is now in cleanup phase. This project is presented as a case study in the development of an exposure database and surveillance system in terms that are generalizable to most other industries and work contexts. Steps include gaining organizational support; defining system purpose and scope; defining database elements and coding; planning practical and efficient analysis strategies; incorporating reporting capabilities; and anticipating communication strategies that maximize the probability that surveillance findings will feed back to preventive applications. For each of these topics, the authors describe both general considerations as well as the specific choices made for this system. An important feature of the system is a two-tier task-coding scheme comprising 33 categories of task groups. Examples of grouped analyses of exposure data captured during the system pilot period demonstrate applications to exposure control, medical surveillance, and other preventive measures. Reprinted by permission of the publisher

    Effect of renal shock wave lithotripsy on the development of metabolic syndrome in a juvenile swine model: a pilot study

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    PURPOSE: We performed a pilot study to assess whether renal shock wave lithotripsy influences metabolic syndrome onset and severity. MATERIALS AND METHODS: Three-month-old juvenile female Ossabaw miniature pigs were treated with shock wave lithotripsy (2,000 shock waves at 24 kV with 120 shock waves per minute in 2) or sham shock wave lithotripsy (no shock waves in 2). Shock waves were targeted to the upper pole of the left kidney to model treatment that would also expose the pancreatic tail to shock waves. Pigs were then instrumented to directly measure arterial blood pressure via an implanted radiotelemetry device. They later received a hypercaloric atherogenic diet for about 7 months. Metabolic syndrome development was assessed by the intravenous glucose tolerance test. RESULTS: Metabolic syndrome progression and severity were similar in the sham treated and lithotripsy groups. The only exception arterial blood pressure, which remained relatively constant in sham treated pigs but began to increase at about 2 months towards hypertensive levels in lithotripsy treated pigs. Metabolic data on the 2 groups were pooled to provide a more complete assessment of metabolic syndrome development and progression in this juvenile pig model. The intravenous glucose tolerance test revealed substantial insulin resistance with impaired glucose tolerance within 2 months on the hypercaloric atherogenic diet with signs of further metabolic impairment at 7 months. CONCLUSIONS: These preliminary results suggest that renal shock wave lithotripsy is not a risk factor for worsening glucose tolerance or diabetes mellitus onset. However, it appears to be a risk factor for early onset hypertension in metabolic syndrome

    Shock wave lithotripsy targeting of the kidney and pancreas does not increase the severity of metabolic syndrome in a porcine model

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    PURPOSE: We determined whether shock wave lithotripsy of the kidney of pigs with metabolic syndrome would worsen glucose tolerance or increase the risk of diabetes mellitus. MATERIALS AND METHODS: Nine-month-old female Ossabaw miniature pigs were fed a hypercaloric atherogenic diet to induce metabolic syndrome. At age 15 months the pigs were treated with 2,000 or 4,000 shock waves (24 kV at 120 shock waves per minute) using an unmodified HM3 lithotripter (Dornier MedTech, Kennesaw, Georgia). Shock waves were targeted to the left kidney upper pole calyx to model treatment that would also expose the pancreatic tail to shock waves. The intravenous glucose tolerance test was done in conscious fasting pigs before lithotripsy, and 1 and 2 months after lithotripsy with blood samples taken for glucose and insulin measurement. RESULTS: Pigs fed the hypercaloric atherogenic diet were obese, dyslipidemic, insulin resistant and glucose intolerant, consistent with metabolic syndrome. Assessments of insulin resistance, glucose tolerance and pancreatic β cell function from fasting plasma glucose and insulin levels, and the glucose and insulin response profile to the intravenous glucose tolerance test were similar before and after lithotripsy. CONCLUSIONS: The metabolic syndrome status of pigs treated with shock wave lithotripsy was unchanged 2 months after kidney treatment with 2,000 high amplitude shock waves or overtreatment with 4,000 high amplitude shock waves. These findings do not support a single shock wave lithotripsy treatment of the kidney as a risk factor for the onset of diabetes mellitus

    Comparison of Tissue Injury from Focused Ultrasonic Propulsion of Kidney Stones Versus Extracorporeal Shock Wave Lithotripsy

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    Purpose Focused ultrasonic propulsion is a new non-invasive technique designed to move kidney stones and stone fragments out of the urinary collecting system. However, the extent of tissue injury associated with this technique is not known. As such, we quantitated the amount of tissue injury produced by focused ultrasonic propulsion under simulated clinical treatment conditions, and under conditions of higher power or continuous duty cycles, and compared those results to SWL injury. Materials and Methods A human calcium oxalate monohydrate stone and/or nickel beads were implanted (with ureteroscopy) into 3 kidneys of live pigs (45–55 kg) and repositioned using focused ultrasonic propulsion. Additional pig kidneys were exposed to SWL level pulse intensities or continuous ultrasound exposure of 10 minutes duration (ultrasound probe either transcutaneous or on the kidney). These kidneys were compared to 6 kidneys treated with an unmodified Dornier HM3 Lithotripter (2400 shocks, 120 SWs/min and 24 kV). Histological analysis was performed to assess the volume of hemorrhagic tissue injury created by each technique (% functional renal volume, FRV). Results SWL produced a lesion of 1.56±0.45% FRV. Ultrasonic propulsion produced no detectable lesion with the simulated clinical treatment. A lesion of 0.46±0.37% FRV or 1.15±0.49% FRV could be produced if excessive treatment parameters were used while the ultrasound probe was placed on the kidney. Conclusions Focused ultrasonic propulsion produced no detectable morphological injury to the renal parenchyma when using clinical treatment parameters and produced injury comparable in size to SWL when using excessive treatment parameters
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