Verification Of Descriptions Research Articles

A Research Landscape on Formal Verification of Software Architecture Descriptions

One of the many different purposes of software architecture descriptions is contributing to an early analysis of the architecture with respect to quality attributes. The critical nature of many software systems calls for formal approaches aiming at precisely verifying if their designed architectures can meet important properties such as consistency, completeness, and correctness. In this context, it is worthwhile investigating the role of architecture descriptions to support the formal verification of software architectures to ensure their quality, as well as how such a process happens and is supported by existing languages and verification tools. To evaluate the research landscape on this subject, we have carried out a systematic mapping study in which we collected and analyzed studies available at the literature on formal verification of architecture descriptions. This work contributes with (i) a structured overview and taxonomy of the current state of the art on this topic and (ii) the elicitation of important issues to be addressed in future research.

Построение компактных тестов для функциональной верификации VHDL-описаний конечных автоматов

Построение компактных тестов для функциональной верификации VHDL-описаний конечных автоматов

Morphology and identification of first instar larvae of Australian blowflies of the genus Chrysomya of forensic importance

Light microscopy photographs, line illustrations and scanning electron microscopy micrographs are provided for first instar larvae of six Australian species of Chrysomya. All species have confirmed or potential in forensic investigations given their carrion-breeding habits. Morphology of the first instar larvae of Ch. nigripes, Ch. rufifacies, Ch. saffranea and Ch. varipes is revised, while larvae of Ch. incisularis and Ch. latifrons are described for the first time. The following morphological structures are documented: pseudocephalon, antennal complex, maxillary palpus, facial mask, thoracic and abdominal spinulation, spiracular field, posterior spiracles and cephaloskeleton. New diagnostic features of the cephaloskeleton and the spinulation of the abdominal segments are described. Verification of earlier descriptions revealed major discrepancies between published data, especially in the case of Ch. nigripes. The present results allow clarification, correction and, especially, complementation of the existing information provided by numerous authors. Finally, an identification key for first instar larvae of Australian necrophagous Chrysomya is presented.

Knowledge to action for solving complex problems: insights from a review of nine international cases.

Solving complex problems such as preventing chronic diseases introduces unique challenges for the creation and application of knowledge, or knowledge to action (KTA). KTA approaches that apply principles of systems thinking are thought to hold promise, but practical strategies for their application are not well understood. In this paper we report the results of a scan of systems approaches to KTA with a goal to identify how to optimize their implementation and impact. A 5-person advisory group purposefully selected 9 initiatives to achieve diversity on issues addressed and organizational forms. Information on each case was gathered from documents and through telephone interviews with primary contacts within each organization. Following verification of case descriptions, an inductive analysis was conducted within and across cases. The cases revealed 5 guidelines for moving from conceiving KTA systems to implementing them: (1) establish and nurture relationships, (2) co-produce and curate knowledge, (3) create feedback loops, (4) frame as systems interventions rather than projects, and (5) consider variations across time and place. Results from the environmental scan are a modest start to translating systems concepts for KTA into practice. Use of the strategies revealed in the scan may improve KTA for solving complex public health problems. The strategies themselves will benefit from the development of a science that aims to understand adaptation and ongoing learning from policy and practice interventions, strengthens enduring relationships, and fills system gaps in addition to evidence gaps. Systems approaches to KTA will also benefit from robust evaluations.

Investigation of simulation-based verification methods for descriptions with functional indeterminacy

The problem of verification of logical descriptions of combinational devices is considered for incompletely functionally defined initial descriptions represented as systems of partially defined Boolean functions on intervals of input variable values. Verification methods based on simulation of combinational circuits for cases of input stimuli represented by ternary and Boolean vectors are investigated.

A pattern-based approach for the verification of business process descriptions

ContextEmpirical studies indicate that companies mostly adopt business process management to support organizational concerns. Consequently, descriptions of business processes usually rely on natural languages or tables. Nevertheless, many companies also intend to support process execution using software (e.g. ERP systems, databases, office applications). This involves significant implementation effort, and therefore the underlying business process description should be correct. ObjectiveThis paper presents an approach for verifying business process descriptions that can be presented in any style, e.g. as text, tables or graphical process model created with some or other process modelling language. MethodBecause of its generality and the availability of tools, model checking is used here to verify business process descriptions. In particular, the SPIN model checker was chosen because it is well-established and continuously improved. The proposed composition-based approach permits the semi-automatic implementation of any kind of business process description in the SPIN tool and the verification of numerous correctness properties, which refer to workflow control flow patterns, safety and liveness. ResultsBecause of systemizing, the proposed approach represents all 43 workflow control-flow patterns by 20 basic ones, six fragments and their relationships. For the basic patterns and fragments, PROMELA inline-constructs are provided, and the set of applicable correctness properties is suggested. The correctness properties are specified as templates in linear temporal logic. Implementing a business process description consists of assembling the inline-constructs and associating business semantics with the symbols in the logical formulae of the correctness properties. For verification, the SPIN algorithms are used. ConclusionBy using the approach presented, business process descriptions can be checked for correctness even if the original business process description is vague. The control structures allowed in the business process descriptions are not restricted, and the verifiable correctness properties go beyond soundness.

Morphology and identification of first instars of the European and Mediterranean blowflies of forensic importance. Part I: Chrysomyinae

Light microscopy photographs, line illustrations and scanning electron micrographs are provided for first instars of Chrysomya albiceps (Wiedemann), Chrysomya megacephala (Fabricius) and Protophormia terraenovae (Robineau-Desvoidy) (all: Diptera: Calliphoridae). The following morphological structures are documented: pseudocephalon; antennal complex; maxillary palpus; facial mask; thoracic and abdominal spinulation; spiracular field; posterior spiracles, and cephaloskeleton. New diagnostic features of the cephaloskeleton and the spinulation of abdominal segments are described. Verification of earlier descriptions revealed major discrepancies among published data. The present results allow for the clarification, correction and, especially, complementation of existing information provided by numerous authors. Finally, an identification key for first-instar larvae of European and Mediterranean Chrysomyinae of forensic importance is presented.

Formal verification of logical descriptions with functional uncertainty based on logarithmic encoding of conditions

We consider the implementability testing problem for a description with functional uncertainty represented with a system of partial Boolean functions (PBF) given by a combinatorial circuit. Implementability testing is based on a formal approach in which we construct a conjunctive normal form (CNF) based on encoding multi-output intervals from the domain of this system. We propose a method for CNF construction related to a system of PBFs which is based on logarithmic encoding of multi-output intervals from the domain of this system and lets one reduce the number of auxiliary variables introduced in the resulting CNF.

СТіЙКіСТЬ МУЛЬТИФРАКТАЛЬНИХ СПЕКТРіВ ВіДНОСНО ЗМіНИ ЯСКРАВОСТі, ПОВОРОТУ і МАСШТАБУ ЗОБРАЖЕННЯ

Verification of multifractal spectra descriptions is conducted in relation to transformation of image: change a brightness, turn in relation to a center and down-scaling. The graphs of firmness are rotined in relation to each of transformations.

113 複雑構造物での解析SEAパラメータのFEMによる検証(解析・動設計,OS-9 モード解析とその応用関連技術,総合テーマ「伝統を,未来へ!」)

This paper verifies the expressions for power input and subsystem energy by modal density of subsystem in Statistical Energy Analysis (SEA) by means of FEM calculation. First, it is shown that the SEA main parameters which include power input, energy of the subsystem and coupling loss factor can be expressed mainly by the modal density. In order to verify their modal density descriptions, FEM calculations are performed to compute subsystem energies, power input and coupling loss factors on four kinds of structures with different non-uniform shapes with the equivalent modal densities. The analytical SEA predictions are also compared with the FEM calculation results.

The degree of word-expansion of lexicalized RRWW-automata — A new measure for the degree of nondeterminism of (context-free) languages

Restarting automata can be seen as analytical variants of classical automata as well as of regulated rewriting systems. We study a measure for the degree of nondeterminism of (context-free) languages in terms of deterministic restarting automata that are (strongly) lexicalized. This measure is based on the number of occurrences of auxiliary symbols (categories) used for recognizing a language as the projection of its characteristic language onto its input alphabet. This type of recognition is typical for analysis by reduction, a method used in linguistics for the creation and verification of formal descriptions of natural languages. Our main results establish a hierarchy of classes of context-free languages and two hierarchies of classes of non-context-free languages that are based on the expansion factor of a language.

Dependence Graph Based Verification and Synthesis of Hardware/Software Co-Designs with SAT Related Formulation

Program slicing is a software-analysis technique that generates System Dependence Graphs (SDGs) by which dependencies among program statements can be identified through their traversal. We have developed a program slicing tool for SpecC, a C-based system level design language for hardware/software co-designs, on top of a program slicer for C/C++. This program slicing tool can generate SDGs from any combined descriptions in C, C++, and SpecC, and can be used to analyze design descriptions for hardware/software co-designs uniformly and smoothly in all the combined descriptions. In this paper, after reviewing our program slicer that generates SDGs, we present verification and synthesis techniques for hardware/software co-designs through various analyses on SDGs and generations of SAT/ILP problems from them. For analysis and verification of the combined descriptions, we examine SDGs statically by traversing them with SAT/ILP solvers as verification engines. With this method, many static checks can be efficiently realized even if the target design descriptions are fairly large. We first present techniques for checking synchronization among concurrent processes described in SpecC through symbolic analysis on SDGs. The techniques could verify the synchronization of MPEG4 descriptions with about 48,000 lines within 10 seconds. The techniques can be applied to automatic conversions between sequential and parallel computations. One such application to automatic program serialization is presented. By using the technique for automatic program serialization, we could serialize Vocoder descriptions with about 10,000 lines in around 1 minute. As for synthesis from the combined descriptions, we present an optimal code generation method based on SAT formulation. It can generate codes for reconfigurable processors with minimum code lengths. The sizes of problems as SAT formulation range from 10,000 to 100,000 variables and 100,000 to 500,000 clauses for the largest configurations. With appropriate uses of the state-of-the-art SAT solvers and related tools, we show that fairly practical sizes of verification and synthesis problems can be solved by analyzing SDGs generated from the combined descriptions.

Verification of Modal Density Descriptions of Analytical SEA Parameters for Structure-Borne Sound by Using FEM

This paper verifies the expressions for power input and subsystem energy by modal density of subsystem in Statistical Energy Analysis (SEA) by means of FEM calculation. First, vibration response in the modal form is used to derive their expressions. It is shown that the employment of average in space and frequency for the power input and subsystem energy of the subsystem can be expressed mainly by the modal density. Coupling loss factor between plate subsystems is also analytically estimated by using the wave theory and is determined mainly by the modal density. In order to verify their modal density descriptions, FEM calculations are performed to compare subsystem energies, power inputs and coupling loss factors on three kinds of structures with different subsystem shapes with the same modal densities. The analytical SEA predictions are also compared with the FEM calculation results.

A Rewriting Semantics for a Software Architecture Description Language

Distributed and concurrent application invariably have coordination requirements. The design of those applications, composed by several (possibly distributed) components, has to consider coordination requirements comprising inter-component interaction styles, and intra-component concurrency and synchronization aspects. In our approach coordination aspects are treated in the software architecture level and can be specified in high-level contracts in CBabel ADL. A rewriting logic semantics for the software architecture description language CBabel is given, revisiting and extending previous work by some of the authors, which now includes a revision of the previous semantics and the addition of new features covering all the language. The CBabel tool is also presented. The CBabel tool is a prototype executable environment for CBabel, that implements the given CBabel's rewriting logic semantics and allows the execution and verification of CBabel descriptions in the Maude system, an implementation of rewriting logic. In this way, software architectures describing complex applications can be formally verified regarding properties such as deadlock and synchronization consistency in the software architecture design phase of its life cycle.

Efficient coverage analysis metric for HDL design validation

Simulation is still the primary approach for the functional verification of register-transfer level circuit descriptions written in hardware description language (HDL). The major problem of the simulation approach is to choose a good metric to gauge the quality of the test patterns. The finite state machine (FSM) coverage test can find most of the design errors in a FSM. However, it is impractical for large designs because of the state explosion problem. In the paper, a higher-level FSM model is proposed to replace the conventional FSM model in the coverage test. The state transition graph can be significantly reduced in the model so that the complexity of the test sets becomes acceptable, even for large designs. This higher-level FSM model, called the semantic finite state machine (SFSM) model, can be easily extracted from the original HDL code automatically with little computation overhead. The advantages of using this model instead of the conventional FSM model in HDL design validation are thoroughly discussed. The implementation results show that it is indeed a promising functional coverage metric.

Localized verification of modular designs

This paper describes a verification technique that 1) enables a designer to verify properties of a partial design where some parts have not yet been completed, 2) yields a number of verification conditions growing linearly with the size of the design description. The technique was developed as part of work aimed at providing high-level tools for specification, verification, analysis, and synthesis of circuit descriptions written in a design language calledSynchronized Transitions [18]. The verification is supported by the mechanical theorem proverlp [5, 10].

Formal verification of VHDL descriptions in the Prevail environment

Prevail, a formal verification environment for proving the equivalence of two very-high-speed integrated circuit hardware description language (VHDL) design architectures, is described. For simple bit-level combinational descriptions, the environment calls upon a tautology checker. For parameterized repetitive structures and for more abstract sequential designs, the program translates descriptions into recursive functions according to predefined templates and generates a theorem acceptable to the Bover-Moore theorem prover. The specification, implementation, and functional representation of a sequential example are presented. >

An Inductive Assertion Method for Register Transfer Level Design Verification

This paper extends Floyd's inductive assertion method to formal verification of register transfer level (RTL) hardware descriptions. An RTL description with imbedded assertions about machine state will be the input to the verifier. The formal semantics of an RTL language for synchronous designs are defined, to make mechanical generation of verification conditions (VC's) possible. These VC's are to be fed to a theorem prover. Proof of all the VC's constitutes complete verification. The semantic rules define how time advances, in addition to how machine variables change. These rules make possible verification of real-time performance as well as logical correctness. Such real-time performance verification is important for some hardware designs. The paper also emphasizes the differences between software and hardware verification. An example is given to illustrate the formal verification method.

Biosystematics of Trichogramma and Trichogrammatoidea Species

erepresent a large group of minute parasitic wasps which attack eggs of various insects, many of which are of economic importance. The small size of trichogrammatids and the relatively uniform morphology of species within each genus have made taxonomic studies difficult, and this has resulted in many nomenclatorial problems. Descriptions of species have often been rather vague, frequently based on one sex, and, in the absence of good type specimens, verification of descriptions has not always been possible. The most recent and comprehensive revisionary study of the family has been made by Doutt & Viggiani (6) , who not only developed an excellent key for separation of the 70-odd genera and subgenera, but have also synonymized many of these groups. These authors have observed that the minuteness of these winged insects has apparently increased their chances of dispersion by wind, and as a result they are even found on remote isolated oceanic islands. Moreover, they are unique in that they occupy all kinds of habitats, from swampy marshlands to hot dry deserts, and occur on low-lying vegetation or in strictly arboreal habitats.

Perceptual coding strategies in the formation and verification of descriptions

Three experiments were carried out to study the "picture coding" process implicit both in making up descriptions of pictures and in verifying descriptions against pictures. In the first experiment, Ss were asked simply to describe pictures of one object above another; some pictures were symmetrical vertically and some were not. In the other two experiments, other Ss were timed as they judged whether sentences likeStar isn't below line were true or false of such pictures. According to the results, Ss comply to three ordered "preference" rules in describing the two objects, rules that are conditional on characteristics of the picture and demands of the task. Furthermore, Ss in the verification task comply to the same three rules when they view and encode the picturebefore they read the sentence to be verified, but to only one of the rules when they view the pictureafter they read the sentence. The results also reconfirm two recently proposed models for the process of verifying sentences against pictures.