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As an emerging wireless communication technology, narrowband Internet of Things is widely used in various scenarios, but it also brings new security problems, especially the group authentication between terminal devices and servers. In narrowband Internet of Things, terminal devices are often deployed in unattended environments, which are vulnerable to various attacks and controlled by adversaries, resulting in identity information leakage. Secondly, a large number of terminal devices send authentication request information to the server at the same time, which is easy to cause network signaling congestion, and the centralized calculation mode of the server will cause a large delay in the authentication process. To solve these problems, we propose an edge-assisted group authentication scheme for narrowband Internet of Things. Firstly, a lightweight encryption algorithm LCHAOSAES was used to encrypt the terminal device identity to prevent the terminal device identity information leakage. Then, the edge computing method was used to add an edge network layer to the NB-IoT system architecture to assist in completing the group authentication of massive terminal devices, and the edge assistance could realize decentralization and reduce the load of centralized processing of the server. The Burrows Abadi Needham logic verification, informal security analysis and performance analysis show that the proposed scheme is robust under malicious attacks such as replay attack, man-in-the-middle attack and insider attack, and has less signaling overhead and delay. [ABSTRACT FROM AUTHOR]

Facing the continuous improvement of war complexity under the trend of system-of-systems confrontation, this paper introduces MBSE to the modeling design of complex system-of-systems combat. Adopting Unified Architecture Framework, a modeling method based on scenes is proposed by sorting out the modeling needs and internal mechanisms of system operations. Taking the task that searching and attacking multiple target as an example, various kinds of view is constructed including strategic, operating, resources and services. Then, logic verification is carried out based on the model. This method can provide a reference for system-of-system combat design and UAF application. [ABSTRACT FROM AUTHOR]

Facing the continuous improvement of war complexity under the trend of system-of-systems confrontation, this paper introduces MBSE to the modeling design of complex system-of-systems combat. Adopting Unified Architecture Framework, a modeling method based on scenes is proposed by sorting out the modeling needs and internal mechanisms of system operations. Taking the task that searching and attacking multiple target as an example, various kinds of view is constructed including strategic, operating, resources and services. Then, logic verification is carried out based on the model. This method can provide a reference for system-of-system combat design and UAF application. [ABSTRACT FROM AUTHOR]

How can we empower social media users to better discern the veracity of news and share less false news? This survey experiment (N  =   636) assessed the effectiveness of two interventions—signing a Pro-Truth Pledge and utilizing a Fact-Checking Guide. Results showed that utilizing the Fact-Checking Guide increased skepticism of news posts, likelihood to verify news posts, verification engagement, and reduced intention to share news without regard to news veracity. Before and after comparisons indicated that after verification engagement activities, truth and sharing discernment improved with higher factual accuracy ratings for true news, lower accuracy ratings for false news, and a greater likelihood to share true news compared to false news. Individual's engagement in verification was identified as a crucial mechanism through which the Fact-Checking Guide intervention led to better truth and sharing discernment. The study could inform social media designs that promote a truthful news environment. [ABSTRACT FROM AUTHOR]

In The Gay Science §341, the thought of eternal return is introduced as the announcement of a "demon." Two possible hearers are described: one is crushed by the demon's speech, while the other is overjoyed. This article argues that these responses are different because they are responses to different messages. One is conveyed in plain words by the demon's speech; the other is implied by a final reference to "this ultimate eternal confirmation and sealing." While that confirmation is provided by what the demon says, not everyone will be aware of it: rather, only someone for whom the value of life has become problematic will be aware of it. Further, it seems that the demon does not understand his own message, since he personifies a will to knowledge that is indifferent to such concerns. Thus, only a human being can gain insight into the value and meaning of life from the thought of eternal return. [ABSTRACT FROM AUTHOR]

In this paper, the graph theory model of the kinematics of the double internal meshing planetary gear is established by splitting the k value of the planetary gear, the system matrix of the dual-state logic planetary gear transmission is assembled, the logic characteristics of the dual-state logic planetary gear transmission control are analyzed, the logic characteristic table of the 32-gear control is established, and the system model of the kinematics analysis and calculation of the entire planetary gear transmission is established. The expressions of rotational speed and transmission ratio of each component (including planetary gear) of the planetary gear in 32 gears are solved and obtained. The efficiency expression of each gear is derived through the Kleinas method, the calculation of the transmission ratio and efficiency of the 32 gears is completed, and the system efficiency diagram is drawn, which provides a reliable basis for the structural design, shift dynamic simulation analysis, and test verification of the dual-state logic planetary transmission. [ABSTRACT FROM AUTHOR]

The aim of this paper is to argue for a revised and precisified version of the infamous Verifiability Criterion for the meaningfulness of declarative sentences. The argument is based on independently plausible premises concerning probabilistic confirmation and meaning as context-change potential, it is shown to be logically valid, and its ramifications for potential applications of the criterion are being discussed. Although the paper is not historical but systematic, the criterion thus vindicated will resemble the original one(s) in some important ways. At the same time, it will also be more modest insofar as meaningfulness will turn out to be relativized linguistically and probabilistically, and different choices of the linguistic and probabilistic parameters may lead to different verdicts on meaningfulness. [ABSTRACT FROM AUTHOR]

In previous work, summarized in this paper, we proposed an operation of parallel composition for rewriting-logic theories, allowing compositional specification of systems and reusability of components. The present paper focuses on compositional verification. We show how the assume/guarantee technique can be transposed to our setting, by giving appropriate definitions of satisfaction based on transition structures and path semantics. We also show that simulation and equational abstraction can be done componentwise. Appropriate concepts of fairness and deadlock for our composition operation are discussed, as they affect satisfaction of temporal formulas. We keep in parallel a distributed and a global view of composed systems. We show that these views are equivalent and interchangeable, which may help our intuition and also has practical uses as, for example, it allows global-style verification of a modularly specified system. Under consideration in Theory and Practice of Logic Programming (TPLP). [ABSTRACT FROM AUTHOR]

Designs inspired by nature are used in several areas as automotive, aerospace and defence industry. In studies on the axial crushing analysis of thin-walled structures such as crashworthiness, a critical role of developments of design aspects have been achieved by the bioinspired perspective. The energy absorption performance of the crashworthiness which shapes the basis of the crushing analysis is the main aspects of the numerical and experimental solution methods. In order to verification of finite element model, the energy absorption characteristic specifications were performed the square tube under axial loads. Using the proposed of lotusinspired design performances of axial load condition, the newly design was prepared square tube included lotus bifurcation as called "bio-hybrid". To compare the axial and oblique loads performances of the L (lotus) and BH (bio-hybrid) structures, forcedeformation curves was evaluated with characteristic properties as EA, CFE, SEA, MCF and PCF. The numerical analysis showed that the square outer frame included lotus bifurcation of crashworthiness is suitable than natural circular lotus configuration under oblique loads. However, the lotus-inspired configuration is determined advantageous under axial loads. [ABSTRACT FROM AUTHOR]

In the context of reinforcement learning (RL), ensuring both safety and performance is crucial, especially in real-world scenarios where mistakes can lead to severe consequences. This study aims to address this challenge by integrating temporal logic constraints into RL algorithms, thereby providing a formal mechanism for safety verification. We employ a combination of theoretical and empirical methods, including the use of temporal logic for formal verification and extensive simulations to validate our approach. Our results demonstrate that the proposed method not only maintains high levels of safety but also achieves comparable performance to traditional RL algorithms. Importantly, our approach fills a critical gap in the existing literature by offering a solution that is both mathematically rigorous and empirically validated. The study concludes that the integration of temporal logic into RL offers a promising avenue for developing algorithms that are both safe and efficient. This work lays the foundation for future research aimed at generalizing this approach to various complex systems and applications. [ABSTRACT FROM AUTHOR]

Copyright of Systems Engineering & Electronics is the property of Journal of Systems Engineering & Electronics Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This article brings a broad array of works, which pertain to different research areas of international relations (IR), into contact with each other via a graphic method, systemism, to obtain insights that otherwise might prove elusive. Completion of these tasks is anticipated to exemplify how the systemist approach can enhance communication throughout IR. Systemism is introduced as a graphic technique for communicating arguments. Systemist graphics are used to convey the contents of (a) two studies that focus on theory per se and (b) a range of topics—foreign policy analysis, forecasting, and conflict processes. Systematic synthesis focusing on the two works about theory and bricolagic bridging that is based on all five studies reveal the contributions of a systemist approach, respectively, to the logics of confirmation and discovery. Value added from the systemist approach is confirmed for both IR research and pedagogy. [ABSTRACT FROM AUTHOR]

Copyright of Study on Optical Communications / Guangtongxin Yanjiu is the property of Study on Optical Communications Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Currently, Internet of Medical Things (IoMT) gained popularity because of an ongoing pandemic. A few developed countries plan to deploy the IoMT for improving the security and safety of frontline workers to decrease the mortality rates of COVID‐19 patients. However, IoMT devices share the information through an open network which leads to increased vulnerability to various attacks. Hence, electronic health management systems remain many security challenges, like recording sensitive patient data, secure communication, transferring patient information to other doctors, providing the data for future medical diagnosis, collecting data from WBAN, etc. In addition, the sensor devices attached to the human body are resource‐limited and have minimal power capacity. Hence, to protect the medical privacy of patients, confidentiality and reliability of the system, the register sensor, doctor and server need to authenticate each other. Therefore, rather than two factors, in this work, a multifactor authentication protocol has been proposed to provide more secure communication. The presented scheme uses biometric and fuzzy extractors for more security purposes. Furthermore, the scheme is proved using informal and formal security verification BAN logic, ProVerif and AVISPA tools. The ProVerif simulation result of the suggested scheme shows that the proposed protocol achieves session key secrecy and mutual authentication [ABSTRACT FROM AUTHOR]

Organizations often use smart card-based user authentication for remote access. The research community has put forward dynamic identity based remote user authentication schemes for distributed multi-server environment to safeguard the connection between user and server. Recently, Qiu et al. proposed an efficient smart card based remote user authentication scheme for the multi-server environment, in which they uphold their scheme provides mutual authentication and key agreement, user-anonymity, resistance against various kind of attacks. This paper will manifest that if the adversary is successful in stealing a smart card, then their schemes are vulnerable to masquerade attack, server spoofing attack, and password guessing attack. We overcome their flaws and propose an enhanced anonymous scheme where whenever the user wants to log into a server, the user identity is changed dynamically before login. And also, the scheme resists all possible attacks. We compared our scheme with respect to the related scheme, used BAN logic for verification of correctness of mutual key agreement and AVISPA to prove scheme is safe. We have provided formal security proofs for our scheme. [ABSTRACT FROM AUTHOR]

This article proposes a new logic synthesis and verification paradigm based on circuit simulation. In this paradigm, high quality, expressive simulation patterns are pregenerated to be reused in multiple runs of optimization and verification algorithms, resulting in reduced time-consuming Boolean computations such as satisfiability (SAT) solving. Methods to generate expressive simulation patterns are presented and compared, and a bit-packing technique to compress them is integrated into the implementation. The generated patterns are shown to be reusable across different algorithms and after network function modifications. A logic synthesis algorithm, Boolean resubstitution, and a verification algorithm, combinational equivalence checking, are two examples of using this paradigm. In simulation-guided Boolean resubstitution, simulation patterns are used for efficient filtering of optimization choices, leading to a lower cost in expanding the search space. By adopting the proposed paradigm, we achieve a 5.9% reduction in the number of AIG nodes, compared to 3.7% by a state-of-the-art resubstitution algorithm, within comparable runtime. In simulation-guided equivalence checking, the number of SAT solver calls is reduced by 9.5% with the use of the expressive simulation patterns accumulated in earlier logic synthesis stages. [ABSTRACT FROM AUTHOR]

Various methods are used to obtain a superior palmprint recognition system. After selecting a palmprint image filter, using Gabor orientation scale pairs is an option to support the refinement of the verification process. Many researchers use the [8×5] pair for the value of the Gabor orientation scale in the field of palmprint recognition. However, from the experiments conducted, other Gabor pairs have more impact on system improvement. The problem is to get the most suitable value pairs for palmprint applications, so in this study, a comparison of seven kinds of Gabor pairs is carried out. This Gabor pair being compared applies using original images, PCA dimension reduction, and the Euclidean method. From the research that has been done, the pair of Gabor orientation scale [8 × 7] or image expansion of 56 will have the most significant impact compared to other pairs. Suppose the result of this Gabor pair is [8×7] by using other improvement systems, namely the 3W filter instead of the original image, KPCA to replace the PCA, and the cosine method in the matching method. In that case, it will increase the verification value by 99.611%. The trial value obtained can be an alternative method of choice for improving palmprint recognition. [ABSTRACT FROM AUTHOR]

Due to the infrastructure provided by the GLOobal MObility NETwork, mobile users are able to access many network services anytime and anywhere, even in a roaming environment. Although, a strong authentication scheme with sufficient security requirements is necessary while accessing such services. Recently, Gope et al. discussed a symmetric key based authentication protocol in this regard. However, we find that their protocol exhibits various shortfalls like privileged insider attack, offline password guessing attack, stolen smart card attack, session key compromised attack, unverified login phase, imperfect forward secrecy, improper mutual authentication, excessive database maintenance cost, synchronization problem and no password changing phase. In this article, we put forward a certificate-less anonymous two-factor authentication protocol based on Elliptic Curve Cryptography (ECC). We use BAN logic for formal verification of the protocol. Moreover, the robustness of the protocol under several security attacks is ensured using AVISPA tool-based automated security validation. The proposed protocol can provide increased security and design properties than many other recently existing schemes. [ABSTRACT FROM AUTHOR]

We present the Software Tool for the Analysis of Robustness in the unKnown environment (Stark), our Java tool for the specification, analysis and verification of robustness properties of Cyber-Physical Systems (CPSs). Stark includes: (i) a specification language for systems behaviour, perturbations, distances on systems behaviours, and requirements on systems behaviour expressed in the Robustness Temporal Logic (RobTL), a temporal logic for the specification and verification of properties on the evolution of distances between the behaviours of CPSs, and thus also of robustness properties; (ii) a module for the simulation of system behaviours and their perturbed versions; (iii) a module for the evaluation of distances between behaviours; (iv) a statistical model checker for RobTL formulae. [ABSTRACT FROM AUTHOR]

Copyright of Railway Signalling & Communication Engineering is the property of Railway Signalling & Communication Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In three experiments, we used a masked prime in a verification task to investigate the processing stages occurring during multiplication fact retrieval. We aimed to investigate the retrieval process by overlapping its execution with the processing of a masked prime consisting of a number. Participants evaluated the correctness of multiplication equations, where the result was preceded by a masked prime (presented for 30 ms, with different stimulus onset asynchrony between the operands and the prime). Decade consistency and relatedness of the prime were manipulated. For example, given the equation 4 x 7 = 28, the prime could be: a neighbor either decade consistent (24) or inconsistent (32), or an unrelated number either decade consistent (23) or inconsistent (31). We expected that the feature of the prime (relatedness or decade consistency) that generates interference depends on the processing stage reached when the prime is processed. Although Experiment 1 showed promising results, Experiments 2 and 3 suggest that the pattern found in Experiment 1 was a false positive. Overall, the paradigm used in this study (i.e., masked prime with a verification ask) does not seem to produce a stable interference during the retrieval process. [ABSTRACT FROM AUTHOR]

Program verification consists in finding a formal proof that the program satisfies a given specification. This specification can be described as assertions about the input and output a correct program must satisfy. Assertions and programs are traditionally specified in terms of classical first order logic (FOL). FOL reasoners (inference systems) automatically find the correspondent program correctness proof, if any. However, verification of programs with mutable data structures, such as pointers, is currently a major challenge for the FOL assertion based approach. Mutable data structures are often written in terms of syntactically unrelated expressions, whose specification represents a significant defiance for FOL. Separation logics are a family of formal languages with specially-purposed constructors designed to model mutable data structures. In this paper, we formally verify a database management system using separation logics. We focused on the verification of libraries containing programs about heap manipulation. Several detected bugs are described in detail, respective solutions are also provided. [ABSTRACT FROM AUTHOR]

Traditional logical equivalence checking (LEC), which plays a major role in the entire chip design process, faces challenges of meeting the requirements demanded by the many emerging technologies that are based on logic models different from the standard complementary metal oxide semiconductor (CMOS). In this article, we propose an LEC framework to be employed in the verification process of superconducting electronics (SCE). Our LEC framework is compatible with the existing CMOS technologies and can also check features and capabilities that are unique to SCE. For instance, the performance of nonresistively biased single-flux quantum (SFQ) circuits benefits from ultradeep pipelining, and verification of such circuits requires new models and algorithms. We, therefore, present the multicycle input dependency circuit model which is a novel model representation of design to explicitly capture the dependency of primary outputs of the circuit on sequences of internal signals and inputs. Embedding the proposed circuit model and several structural checking modules, the process of verification can be independent of the underlying technology and signaling. We benchmark the proposed framework on postsynthesis SFQ and 4-phase adiabatic quantum flux parametron netlists. Results show a comparative verification time of SFQ circuit benchmark, including 16-bit integer divider and ISCAS’85 circuits with respect to the ABC tool for similar CMOS circuits. [ABSTRACT FROM AUTHOR]

A puzzle arises when combining two individually plausible, yet jointly incompatible, norms of inquiry. On the one hand, it seems that one should not inquire into a question while believing an answer to that question. But, on the other hand, it seems rational to inquire into a question while believing its answer, if one is seeking confirmation. Millson (2021) , who has recently identified this puzzle, suggests a possible solution, though he notes that it comes with significant costs. I offer an alternative solution, which does not involve these costs. The best way to resolve the puzzle is to reject the prohibition on inquiring into a question while believing an answer to it. Resolving the puzzle in this way makes salient two fruitful areas in the epistemology of inquiry that merit further investigation. The first concerns the nature of the inquiring attitudes and the second concerns the aim(s) of inquiry. [ABSTRACT FROM AUTHOR]

A. J. Ayer's empiricist criterion of meaning was supposed to have sorted all statements into nonsense on the one hand, and tautologies or genuinely factual statements on the other. Unfortunately for Ayer, it follows from classical logic that his criterion is trivial—it classifies all statements as either tautologies or genuinely factual, but none as nonsense. However, in this paper, I argue that Ayer's criterion of meaning can be defended from classical proofs of its triviality by the adoption of a relevant logic—an idea which is motivated because, according to Ayer, the genuinely factual statements are those which observation is relevant to. [ABSTRACT FROM AUTHOR]

According to Goldman and Olsson's so‐called conditional probability solution to the extra‐value‐of‐knowledge problem, knowledge is more valuable than mere true belief because having the former makes the acquisition of further similar true beliefs in the future more likely than having the latter does. Unfortunately, however, several philosophers have rejected the comparative probability claim Goldman and Olsson's solution is based on. In this paper, I present a new argument in defence of this claim. More precisely, I point out a highly plausible necessary and sufficient condition for the latter and argue for its truth by bringing together confirmation‐theoretic and reliabilist considerations. I also explain where a number of objections against Goldman and Olsson's probabilistic claim seem to go wrong. [ABSTRACT FROM AUTHOR]

Threshold logic (TL) circuits gain increasing attention due to their feasible realization with emerging technologies and strong bind to neural network applications. In this work, we devise techniques for automatic synthesis and verification of TL circuits based on constraint solving. For synthesis, we formulate a fundamental operation to collapse TL functions, and derive a necessary and sufficient condition of collapsibility for linear combination of two TL functions. An approach based on solving the subset sum problem is proposed for fast circuit transformation. For verification, we propose a procedure to convert a TL function to a multiplexer (MUX) tree and to pseudo-Boolean (PB) constraints for formal Boolean and PB reasoning, respectively. Experiments on synthesis show that the collapse operation further reduces gate counts of synthesized TL circuits by an average of 18%. Experiments on verification demonstrate good scalability of the MUX-based method for equivalence checking of synthesized TL circuits, and efficiency of PB constraint conversion in cases where the conjunctive normal form (CNF) formula conversion and MUX tree conversion suffer from memory explosion. [ABSTRACT FROM AUTHOR]

Creating computing systems able to address our ever-increasing needs, especially as we reach the end of CMOS transistor scaling, will require truly novel methods of computing. However, the traditional logic abstractions and the digital design patterns we understand so well have coevolved with the hardware technology that has embodied them. As we look past CMOS, there is no reason to think that those same abstractions best serve to encapsulate the computational potential inherent to emerging devices. We posit that a new and radically more efficient foundation for computing lies at the intersection of superconductor electronics and delay-coded computation. Building on recent work in race logic, we show that superconducting circuits can naturally compute directly over temporal relationships between pulse arrivals; that the computational relationships between those pulse arrivals can be formalized through a functional extension to a temporal predicate logic used in the verification community; and that the resulting architectures can operate asynchronously and describe real and useful computations. We verify our hypothesis through a combination of detailed analog circuit models and layout designs, a formal analysis of our abstractions, and an evaluation of several superconducting temporal accelerators. [ABSTRACT FROM AUTHOR]

The article talks about our design of ultrasound-based localization system. The designed system is primarily intended for mobile robotics. The second part of this article is focused on the initial verification of the basic characteristics and accuracy of the position measurement. This location system is currently still in the process of improving the functions required for usage in mobile robotics. We are currently working on removing some types of interferences. [ABSTRACT FROM AUTHOR]

Writing correct programs for weak-memory models such as the C11 memory model is challenging because of the weak consistency guarantees these models provide. The first program logics for the verification of such programs have recently been proposed, but their usage has been limited thus far to manual proofs. Automating proofs in these logics via first-order solvers is non-trivial, due to features such as higher-order assertions, modalities and rich permission resources. In this paper, we provide the first encoding of a weak-memory program logic using existing deductive verification tools. Our work enables, for the first time, the (unbounded) verification of C11 programs at the level of abstraction provided by the program logics; the only necessary user interaction is in the form of specifications written in the program logic and, in rare cases, ghost operations. We tackle three recent program logics: Relaxed Separation Logic and two forms of Fenced Separation Logic, and show how these can be encoded using the Viper verification infrastructure. In doing so, we illustrate several novel encoding techniques which could be employed for other logics. Our work is implemented, and has been evaluated on examples from existing papers as well as the Facebook open-source Folly library. [ABSTRACT FROM AUTHOR]

Providing Privacy and security for aggregated data in wireless sensor networks has drawn the attention of practicing engineers and researchers globally. Several cryptographic methods have been already proposed to solve security and data integrity problems for aggregated data. Matrix cryptography is a better option for creating secure encryption/decryption algorithms to counter quantum attack. However, these algorithms have higher computational cost and increased communication overhead. Hence, a new technique of loss-less secure data aggregation in Clustered Wireless Sensor Networks is presented. The proposed method uses integer matrices as keys for data security and data integrity. Matrix operations are carried out in finite field Zp. Loss-less secure data aggregation is extended for homomorphic summation while the cipher text expansion ratio is kept substantially low. The proposed algorithm has inbuilt fast and efficient signature verification facility. The execution time of our signature verification mechanism is found to be approximately 50 percent less compared to a couple of standard existing signature verification schemes. [ABSTRACT FROM AUTHOR]

Verifying the correctness of a system as a whole requires establishing that it satisfies a global specification. When it does not, it would be helpful to determine which modules are incorrect. As a consequence, specification decomposition is a relevant problem from both a theoretical and practical point of view. Until now, specification decomposition has been independently addressed by the control theory and verification communities through natural projection and partial model checking, respectively. We prove that natural projection reduces to partial model checking and, when cast in a common setting, the two are equivalent. Apart from their foundational interest, our results build a bridge whereby the control theory community can reuse algorithms and results developed by the verification community. Furthermore, we extend the notions of natural projection and partial model checking from finite-state to symbolic transition systems and we show that the equivalence still holds. Symbolic transition systems are more expressive than traditional finite-state transition systems, as they can model large systems, whose behavior depends on the data handled, and not only on the control flow. Finally, we present an algorithm for the partial model checking of both kinds of systems that can be used as an alternative to natural projection. [ABSTRACT FROM AUTHOR]

In this paper, a new set of configurations are proposed to implement simple and highly compact photonic crystal based all-optical logic AND and OR gates. These newly designed logic gates operate at the telecommunication wavelength of 1550 nm and consume very low power compared to the existing designs. The basic all-optical logic gates are cascaded to operate as the universal gates NAND and NOR. The various parameters such as response time, contrast ratio and footprint are analyzed and optimized based on structure parameters such as radius and lattice constant. The proposed structures have very low power consumption in the range of 1 μ W with a footprint of 168 μ m 2 for the AND gate and 150 μ m 2 for the OR gate respectively. The value of contrast ratio for the proposed AND gate is 8.45 dB. The response time for OR gate is 0.4 ps and that of AND gate is 0.16 ps resulting in bitrates up to 6.25 Tbps. The contrast ratio obtained for the cascaded operation of NAND and NOR gates are 5.29 dB and 5.3 dB respectively. The band gap diagram for the proposed gates are attained using Plane Wave Expansion method and their performance is studied using Finite Difference Time Domain technique. Further, the realization of De Morgan's law is achieved by cascading the proposed all-optical logic gates and hence verifying the truth tables for the same. [ABSTRACT FROM AUTHOR]

We propose a general system that combines the powerful features of modal logic and many-sorted reasoning. Its algebraic semantics leads to a many-sorted generalization of boolean algebras with operators, for which we prove the analogue of the Jónsson-Tarski theorem. Our goal was to deepen the connections between modal logic and program verification, while also testing the expressiveness of our system by defining a small imperative language and its operational semantics. [ABSTRACT FROM AUTHOR]

The Alternating-time Temporal Logic (ATL) is a temporal logic for formal verification of open systems, which supports selective quantification over paths. The open system can be represented as a game where the system and the environment pick their moves in turn or simultaneously. The ATL model checker Mocha has been developed by using Binary Decision Diagrams (BDDs), and successfully employed for open system verification. However, since Mocha symbolically manipulates a set of states by a BDD, it is hard to generate a winning strategy as a witness or a counter-example. In this paper, we propose a novel algorithm to efficiently construct a winning strategy tree and report that our technique has been successfully implemented on Mocha. [ABSTRACT FROM AUTHOR]

SAT solvers decide the satisfiability of Boolean formulas in conjunctive normal form. They are commonly used for software and hardware verification. Modern SAT solvers are highly complex and optimized programs. As a single bug in the solver may invalidate the verification of many systems, SAT solvers output certificates for their answer, which are then checked independently. However, even certificate checking requires highly optimized non-trivial programs. This paper presents the first SAT solver certificate checker that is formally verified down to the integer sequence representing the formula. Our tool supports the full DRAT standard, and is even faster than the unverified state-of-the-art tool drat-trim, on a realistic set of benchmarks drawn from the 2016 and 2017 SAT competitions. An optional multi-threaded mode further reduces the runtime, in particular for big certificates. [ABSTRACT FROM AUTHOR]

Intuitionistic epistemic logic introduces an epistemic operator to intuitionistic logic, which reflects the intended Brouwer–Heyting–Kolmogorov (BHK) semantics of intuitionism. The fundamental assumption concerning intuitionistic knowledge and belief is that it is the product of verification. The BHK interpretation of intuitionistic logic has a precise formulation in the logic of proofs and its arithmetical semantics. We show here that this interpretation can be extended to the notion of verification upon which intuitionistic knowledge is based, providing the systems of intuitionistic epistemic logic based on verification with an arithmetical semantics too. This confirms that the conception of verification incorporated in these systems reflects the BHK interpretation. [ABSTRACT FROM AUTHOR]

Philosophers such as Goodman (1954), Scheffler (1963) and Glymour (1983) aim to answer the Paradox of the Ravens by distinguishing between confirmation simpliciter and selective confirmation. The latter evidential relation occurs when data not only confirms a hypothesis, but also disconfirms one of its 'rival' hypotheses. The appearance of paradox is allegedly due to a conflation of valid intuitions about selective confirmation with our intuitions about confirmation simpliciter. Theories of evidence, like the standard Bayesian analysis, should only be understood as explications of confirmation simpliciter; when we disambiguate between selective confirmation and confirmation simpliciter, there is no longer a paradox from these theories. Bandyopadhyay and Brittan (2006) have revived this answer within a sophisticated Bayesian analysis of confirmation and severe testing. I argue that, despite the attractive features of the Selective Confirmation Answer, there is no analysis of this evidential relation that satisfactorily answers the Paradox of the Ravens, and the prospects for any answer along these lines are bleak. We must look elsewhere. [ABSTRACT FROM AUTHOR]

Model checking and automated theorem proving are two pillars of formal verification methods. This paper investigates model checking from an automated theorem proving perspective, aiming at combining the expressiveness of automated theorem proving and the complete automaticity of model checking. It places the focus on the verification of temporal logic properties of Kripke models. The main contributions are (i) introducing an extended computation tree logic that allows polyadic predicate symbols; (ii) designing a proof system for this logic, taking Kripke models as parameters; (iii) developing a proof search algorithm for this system and a new automated theorem prover to implement it. The verification process of the new prover is completely automatic and produces either a counterexample when the property does not hold, or a certificate when it does. The experimental results compare well to existing state-of-the-art tools on some benchmarks, and the efficiency is illustrated by the application to an air traffic control problem. [ABSTRACT FROM AUTHOR]

We present a proof of the equivalence between two deductive systems for constructive necessity, namely an axiomatic characterisation inspired by Hakli and Negri's system of derivations from assumptions for modal logic , a Hilbert-style formalism designed to ensure the validity of the deduction theorem, and the judgmental reconstruction given by Pfenning and Davies by means of a natural deduction approach that makes a distinction between valid and true formulae, constructively. Both systems and the proof of their equivalence are formally verified using the state-of-the-art proof assistant Coq. The proof approach taken throughout the paper unveils the use of some alternative proof methods that allow for a smooth transition from the high-level mathematical proofs to their mechanised counterparts. [ABSTRACT FROM AUTHOR]

Reynolds' separation logical system for pointer program verification is investigated. This paper proves its completeness theorem that states that every true asserted program is provable in the logical system. In order to prove the completeness, this paper shows the expressiveness theorem that states the weakest precondition of every program and every assertion can be expressed by some assertion. This paper also introduces an extension of the assertion language with inductive definitions and proves the soundness theorem, the expressiveness theorem, and the completeness theorem. [ABSTRACT FROM AUTHOR]

The authentication properties of a security protocol are specified based on the knowledge gained by the principals that exchange messages with respect to the steps of that protocol. As there are many successful attacks on authentication protocols, different formal systems, in particular epistemic and temporal epistemic logics, have been developed for analyzing such protocols. However, such logics may fail to detect some attacks. To promote the specification and verification power of these logics, researchers may try to construct them in such a way that they preserve some properties such as soundness, completeness, being omniscience-free, or expressiveness. The aim of this paper is to provide an overview of the epistemic and temporal epistemic logics which are applied in the analysis of authentication protocols to find out how far these logical properties may affect analyzing such protocols. [ABSTRACT FROM AUTHOR]