On Formal Specification of Maple Programs

This paper is an example-based demonstration of our initial results on the formal specification of programs written in the computer algebra language MiniMaple (a substantial subset of Maple with slight extensions). The main goal of this work is to define a verification framework for MiniMaple. Formal specification of MiniMaple programs is rather complex task as it supports non-standard types of objects, e.g. symbols and unevaluated expressions, and additional functions and predicates, e.g. runtime type tests etc. We have used the specification language to specify various computer algebra concepts respective objects of the Maple package DifferenceDifferential developed at our institute

Sound and Complete Runtime Security Monitor for Application Software

Conventional approaches for ensuring the security of application software at run-time, through monitoring, either produce (high rates of) false alarms (e.g. intrusion detection systems) or limit application performance (e.g. run-time verification). We present a runtime security monitor that detects both known and unknown cyber attacks by checking that the run-time behavior of the application is consistent with the expected behavior modeled in application specification. This is crucial because, even if the implementation is consistent with its specification, the application may still be vulnerable due to flaws in the supporting infrastructure (e.g. the language runtime system, libraries and operating system). This runtime security monitor is sound and complete, eliminating false alarms, as well as efficient, so that it does not limit runtime application performance and so that it supports real-time systems. The security monitor takes as input the application specification and the application implementation, which may be expressed in different languages. The specification language of the application software is formalized based on monadic second order logic and event calculus interpreted over algebraic data structures. This language allows us to express behavior of an application at any desired (and practical) level of abstraction as well as with high degree of modularity. The security monitor detects every attack by systematically comparing the application execution and specification behaviors at runtime, even though they operate at two different levels of abstraction. We define the denotational semantics of the specification language and prove that the monitor is sound and complete. Furthermore, the monitor is efficient because of the modular application specification at appropriate level(s) of abstraction

Technique detection software for Sparse Matrices

Sparse storage formats are techniques for storing and processing the sparse matrix data efficiently. The performance of these storage formats depend upon the distribution of non-zeros, within the matrix in different dimensions. In order to have better results we need a technique that suits best the organization of data in a particular matrix. So the decision of selecting a better technique is the main step towards improving the system's results otherwise the efficiency can be decreased. The purpose of this research is to help identify the best storage format in case of reduced storage size and high processing efficiency for a sparse matrix

Effect of Leverage on Stock Returns and Systematic Risk: Evidence from Pakistani Industries

This paper evaluates the effect of leverage on stock returns and systematic risk in the corporate sector of Pakistan. It determines the relationship between leverage and systematic risk. Data was collected from eight industries such as; Cotton, Engineering, Chemicals, Sugar and Allied, Cement, Fuel and Energy, and transport and Communications. High leverage was experienced which leaded to high level of systematic risk and volatility in the stock prices

Modeling of Dielectric Resonator Antennas using Numerical Methods Applied to EPR

This chapter presents an inclusive analysis of notable techniques carried out on modeling of dielectric resonator (DR)-antenna using numerical methods in last more than two decades. Dielectric resonator antenna (DRA) has created its individual existence in antenna engineering because of its captivating characteristics like; small size, low loss, high efficiency, wide bandwidth, three-dimensional design flexibility as compared to conventional antennas, etc. The DR antennas are being widely modeled using numerical methods nowadays. The triple-folded intention of this chapter is to: (1) give an overview on DRA modeling using single and hybrid numerical methods, (2) give a compressive review of notable numerical modeling researches carried out on DRAs and (3) give some favorable future concentration for the antenna researchers in order to apply the numerical methods on some innovative geometries of DRAs

On the Formal Semantics of the Cognitive Middleware AWDRAT

The purpose of this work is two fold: on one hand we want to formalize the behavior of critical components of the self generating and adapting cognitive middleware AWDRAT such that the formalism not only helps to understand the semantics and technical details of the middleware but also opens an opportunity to extend the middleware to support other complex application domains of cybersecurity; on the other hand, the formalism serves as a prerequisite for our proof of the behavioral correctness of the critical components to ensure the safety of the middleware itself. However, here we focus only on the core and critical component of the middleware, i.e. Execution Monitor which is a part of the module "Architectural Differencer" of AWDRAT. The role of the execution monitor is to identify inconsistencies between run-time observations of the target system and predictions of the System Architectural Model. Therefore, to achieve this goal, we first define the formal (denotational) semantics of the observations (run-time events) and predictions (executable specifications as of System Architectural Model); then based on the aforementioned formal semantics, we formalize the behavior of the "Execution Monitor" of the middleware

Securing industrial cyber-physical systems: A run-time multi-layer monitoring

Industrial Cyber-Physical Systems (ICPSs) are widely deployed in monitoring and control of the nation's critical industrial processes such as water distribution networks and power grids. ICPSs are the tight integration of cyber (software) and physical entities connected via communication networks. Communication networks are typically realised via wireless channels to reduce the cost of wires and installation. However, they are also inherently unreliable, easy to disrupt and subvert, which makes them a potential target for cyber attacks. The failure of communication can cause data loss or delays, which can compromise system functionality and have catastrophic consequences due to the strict real-time requirements of ICPSs. Current run-time security monitors protect ICPSs either at communication level (through network intrusion monitors) or application level (through threat detection monitors). Such monitors are layer-specific and thus fail to detect advanced threats arising from the multi-layer disruption. In this paper, we present a multi-layer run-time security monitor that can detect discrepancies caused by interdependent application and communication layer attacks and prevent their propagation into the system's control loops. We demonstrate the effectiveness of the approach via an example of the ICPS used for control and monitoring of a water distribution network

Comparative Analysis of Flexural Capacity of Bamboo Reinforced and Conventional Steel Reinforced Concrete Beams Through Numerical Evaluation

Steel reinforcement bars are commonly used in the building industry, but their production contributes to toxic waste and emissions. Bamboo is being marketed as a sustainable alternative due to its low cost and tensile strength. It is a readily available natural material that can potentially replace steel as a conventional reinforcement. The idea of hybrid beams (50% bamboo and 50% steel) was developed to get equal outcomes in terms of the structural reaction, and ABAQUS was used to develop a set of beams. By using conventional dimensions and material qualities, a total of five beams were modeled. According to the analysis, the maximum displacements for each beam would be different. The load-displacement curve of five beams was obtained and it was determined that when combined with steel, bamboo may partially replace it

High-Temperature Annealing of AlGaN

In the past few years, high-temperature annealing of AlN has become a proven method for providing AlN layers with low dislocation densities. Herein, the example of Al0.77Ga0.23N is used to investigate whether annealing can also improve the material quality of the ternary alloy. A detailed analysis of the influence of annealing temperature on structural and optical material properties is presented. It is found that with increasing annealing temperature, the threading dislocation density can be lowered from an initial value of 6.0 × 109 down to 2.6 × 109 cm−2. Ga depletion at the AlGaN surface and Ga diffusion into the AlN buffer layer are observed. After annealing, the defect luminescence between 3 and 4 eV is increased, accompanied by an increase in the oxygen concentration by about two orders of magnitude. Furthermore, due to annealing optical absorption at 325 nm (3.8 eV) occurs, which increases with increasing annealing temperature. It is assumed that the reason for this decrease in ultraviolet (UV) transmittance is the increasing number of vacancies caused by the removal of group-III and N atoms from the AlGaN lattice during annealing