A Rule Set to Detect Interference of Runtime Enforcement Mechanisms

Runtime enforcement aims at verifying the active execution trace of executing software against formally specified properties of the software, and enforcing the properties in case that they are violated in the active execution trace. Enforcement mechanism of individual properties may interfere with each other, causing the overall behavior of the executing software to be erroneous. As the number and the complexity of the properties to be enforced increase, manual detection of the inferences becomes an error-prone and effort-consuming task. Hence, we aim at providing a framework for automatic detection of interferences. As the initial steps to create such a framework, in this paper we first provide formal definitions of an enforcement mechanism and enforcement operators. Second, we define a rule set to detect the interference among properties

A Pointcut Language for Setting Advanced Breakpoints

In interactive debugging, it is an essential task to set breakpoints specifying where a program should be suspended at runtime to allow interaction. A debugging session may use multiple logically related breakpoints so that the sequence of their (de)activations leads to the expected suspension with the least irrelevant suspensions. A (de)activation is sometimes decided by some runtime context values related to that breakpoint. However, existing breakpoints, which are mainly based on line locations, are not expressive enough to describe the logic and the collaboration. Programmers have to manually perform some repeated tasks, thus debugging efficiency is decreased. In this paper, we identify five frequently encountered debugging scenarios that require to use multiple breakpoints. For such scenarios, it is often easier than using the traditional debugger to write pointcuts in an aspect-oriented language, and to suspend the execution at the selected join points. However, existing languages cannot handle the scenarios neatly and uniformly. Therefore, we design and implement a breakpoint language that uses pointcuts to select suspension times in the program. Our language allows programmers to use comprehensible source-level abstractions to define breakpoints. Also, multiple breakpoints can be freely composed to express their collaboration. In this way, an expected suspension can be expressively programmed and reached with less or even no irrelevant suspensions

Non-metallic brush seals for gas turbine bearings

A non-metallic brush seal has been developed as an oil seal for use in turbomachinary. Traditionally labyrinth-type seals with larger clearances have been used in such applications. Labyrinth seals have higher leakage rates and can undergo excessive wear in case of rotor instability. Brush seals reduce leakage by up to an order of magnitude and provide compliance against rotor instabilities. Brush seals are compact and are much less prone to degradation associated with oil sealing. This paper describes the benefits and development of the nonmetallic brush seals for oil sealing application

Increased serum neuregulin 4 levels in women with polycystic ovary syndrome: A case-control study

Neuregulin 4 (NRG4) is an adipokine that is synthesized in many tissues and has been shown to be associated with the development of obesity and metabolic disorders in animals and humans. The aim of this study is to investigate the relationship between serum NRG4 levels and various metabolic parameters in women with PCOS. This cross-sectional study included 40 women with PCOS and 40 age- and BMI-matched controls without PCOS. NRG4, fasting blood glucose (FBG), insulin, hs-CRP, LDL-C, HDL-C, SHBG, DHEA-SO4 and total-testosterone levels were measured in all the participants. HOMA-IR was used to calculate the insulin resistance. Serum NRG4 levels were higher in women with PCOS than in healthy women (24.89 ± 9.32 [ng/mL] vs. 18.98 ± 6.40 [ng/mL], p = 0.002). FBG, LDL-C, HDL-C, LH, SHBG, FAI, DHEA-SO4, insulin, hs-CRP, HOMA-IR and total-testosterone levels were significantly higher in women with PCOS than controls. Circulating NRG4 levels were positively correlated with HOMA-IR, insulin and hs-CRP for both groups. There was a positive correlation between NRG4 and FBG in the PCOS group. HOMA-IR and hs-CRP were associated with NRG4. The high concentration of circulating NRG4 in PCOS may be associated with insulin resistance and low-grade chronic inflammation

NITRIC OXIDE AND LACTATE RESPONSES TO MAXIMAL INTERMITTENT ACUTE EXERCISE

Abstract. Nitric oxide (NO) is a gas with vasodilator and metabolic regulator properties. The present study aimed to examine the relation between NO and lactic acid, and NO difference in acute anaerobic and aerobic loads in aerobic and anaerobic exercise groups. Three groups participated in this study; each group consisted of 11 men with similar physical characteristics. The groups consisted of swimmers as the aerobic group (AeG), volleyball players as the anaerobic group (AnG), and control group (CG). Participants were given 3 acute exercise phases in the scope of lactate minimum speed test (LMSt). NO and lactic acid measurements were taken at particular phases in LMSt. Lactate minimum speed values of AeG (11.5±1.1 km·h-1) were significantly higher than those of the CG (p0.05; 9.2%) than the base NO. Additionally, contrary to the AnG, an increase was observed in ΔNOlevel during active recovery and in NO level after the reloading phase in AeG. Also, lactate elimination level of the aerobic group was higher than the other groups. As a result; these findings show the role of a more active lactate elimination capacity since NO levels in the aerobic group are higher than the other groups following a maximal intermittent exercise.Key words: Nitric oxide, lactate minimum, performance, aerobic, anaerobic

Deriving minimal models for resource utilization

We show how compact Resource Utilization Models (RUMs) can be extracted from concrete overly-detailed models of systems or sub-systems in order to model energy-aware software. Using the Counterexample-Guided Abstraction Refinement (CEGAR) approach, along with model-checking tools, abstract models can be generated that help establish key properties relating to energy consumption. This approach is illustrated by the concrete example of a network manager sub-system. This work is part of an overall design methodology for energy-aware software

Optimizing decomposition of software architecture for local recovery

Cataloged from PDF version of article.The increasing size and complexity of software systems has led to an amplified number of potential failures and as such makes it harder to ensure software reliability. Since it is usually hard to prevent all the failures, fault tolerance techniques have become more important. An essential element of fault tolerance is the recovery from failures. Local recovery is an effective approach whereby only the erroneous parts of the system are recovered while the other parts remain available. For achieving local recovery, the architecture needs to be decomposed into separate units that can be recovered in isolation. Usually, there are many different alternative ways to decompose the system into recoverable units. It appears that each of these decomposition alternatives performs differently with respect to availability and performance metrics. We propose a systematic approach dedicated to optimizing the decomposition of software architecture for local recovery. The approach provides systematic guidelines to depict the design space of the possible decomposition alternatives, to reduce the design space with respect to domain and stakeholder constraints and to balance the feasible alternatives with respect to availability and performance. The approach is supported by an integrated set of tools and illustrated for the open-source MPlayer software