Formal Justification Research Articles

Formal models and justifications of democracy

Recently, some epistemic democrats have taken a result from Hong and Page (Proc Natl Acad Sci 101(46):16385–16389, 2004) to help justify the virtues of deliberative democracy. In this paper, I present novel computational models and show that the result fails to be robust in ways that undermine it as evidence for justifying the virtues of deliberative democracy. In particular, the same model lauded by epistemic deliberative democrats can also be used to support certain kinds of epistocracy.

Bootstrap inference on a factor model based average treatment effects estimator

We propose a novel bootstrap procedure for conducting inference for factor model-based average treatment effects estimators. Our method overcomes bias inherent to existing bootstrap procedures and substantially improves upon existing large sample normal inference theory in small sample settings. The finite sample improvements arising from the use of our proposed procedure are illustrated via a set of Monte Carlo simulations, and formal justification for the procedure is outlined.

On Derkachov–Manashov R-matrices for the principal series of unitary representations

In 2001–2013 Derkachov and Manashov with coauthors obtained simple and natural expressions of R-matrices for the principal series of representations of the groups SL(2,C), SL(2,R), SL(n,C), SO(1, n). The Yang–Baxter identities for these intertwining operators are kinds of multivariate hypergeometric transformations. Derivations of the identities are based on calculations “of physical level of rigor” with divergent integrals. Our purpose is a formal mathematical justification of these results.

Numerical Covariance Evaluation for Linear Structures Subject to Non-Stationary Random Inputs

Random vibration analysis is a mathematical tool that offers great advantages in predicting the mechanical response of structural systems subjected to external dynamic loads whose nature is intrinsically stochastic, as in cases of sea waves, wind pressure, and vibrations due to road asperity. Using random vibration analysis is possible, when the input is properly modeled as a stochastic process, to derive pieces of information about the structural response with a high quality (if compared with other tools), especially in terms of reliability prevision. Moreover, the random vibration approach is quite complex in cases of non-linearity cases, as well as for non-stationary inputs, as in cases of seismic events. For non-stationary inputs, the assessment of second-order spectral moments requires resolving the Lyapunov matrix differential equation. In this research, a numerical procedure is proposed, providing an expression of response in the state-space that, to our best knowledge, has not yet been presented in the literature, by using a formal justification in accordance with earthquake input modeled as a modulated white noise with evolutive parameters. The computational efforts are reduced by considering the symmetry feature of the covariance matrix. The adopted approach is applied to analyze a multi-story building, aiming to determine the reliability related to the maximum inter-story displacement surpassing a specified acceptable threshold. The building is presumed to experience seismic input characterized by a non-stationary process in both amplitude and frequency, utilizing a general Kanai–Tajimi earthquake input stationary model. The adopted case study is modeled in the form of a multi-degree-of-freedom plane shear frame system.

User Experience Techniques Adopted by Brazilian Game Development Studios: An Exploratory Study

Game development studios deal with numerous challenges to achieve the publication of games that are acclaimed by the public. The difficulties range from a simple choice of color for a particular object within the game to mechanics and narratives. In this way, user experience (UX) techniques provide a better perception of the player’s experience. UX techniques are consolidated in the context of software engineering industries and literature. However, few works in the literature (which will be presented in this work) address this knowledge and treat digital games as a specific type of software. In this sense, we aim to explore and present innovative approaches and best techniques adopted by game development studios to integrate UX into their processes. The research included the participation of 41 digital game development studios from all regions of Brazil, of which 31 were interviewed and 10 chose to participate via questionnaire. The analysis revealed that many participants work in small companies (up to five employees) and apply UX techniques intuitively without formal knowledge and justification for using them. Furthermore, we noticed that many studios are unclear about their techniques and confuse them with game design. However, most understand that UX is fundamental for designing a successful game with community support and buy‐in. In addition, most of the justifications for not using UX techniques converged on a lack of knowledge. Finally, we developed a visual scheme to assist studios and future research, capable of consolidating the information extracted from participants about the UX techniques adopted, the benefits and challenges of applying them to the development process, the justifications for not adopting UX techniques (when not adopted), the test instruments implemented, and the UX dimensions evaluated by them.

LTL-specification for development and verification of control programs

This work continues the series of articles on development and verification of control programs based on the LTL-specification. The essence of the approach is to describe the behavior of programs using formulas of linear temporal logic LTL of a special form. The developed LTL-specification can be directly verified by using a model checking tool. Next, according to the LTL-specification, the program code in the imperative programming language is unambiguously built. The translation of the specification into the program is carried out using a template. The novelty of the work consists in the proposal of two LTL-specifications of a new form — declarative and imperative, as well as in a more strict formal justification for this approach to program development and verification. A transition has been made to a more modern verification tool for finite and infinite systems — nuXmv. It is proposed to describe the behavior of control programs in a declarative style. For this purpose, a declarative LTL-specification is intended, which defines a labelled transition system as a formal model of program behavior. This method of describing behavior is quite expressive — the theorem on the Turing completeness of the declarative LTL-specification is proved. Next, to construct program code in an imperative language, the declarative LTL-specification is converted into an equivalent imperative LTL-specification. An equivalence theorem is proved, which guarantees that both specifications specify the same behavior. The imperative LTL-specification is translated into imperative program code according to the presented template. The declarative LTL-specification, which is subject to verification, and the control program built on it are guaranteed to specify the same behavior in the form of a corresponding transition system. Thus, during verification, a model is used that is adequate to the real behavior of the control program.

The Accuracy of Computational Results from Wolfram Mathematica in the Context of Summation in Trigonometry

This article explores the accessibility of symbolic computations, such as using the Wolfram Mathematica environment, in promoting the shift from informal experimentation to formal mathematical justifications. We investigate the accuracy of computational results from mathematical software in the context of a certain summation in trigonometry. In particular, the key issue addressed here is the calculated sum ∑n=044tan⁡1+4n°. This paper utilizes Wolfram Mathematica to handle the irrational numbers in the sum more accurately, which it achieves by representing them symbolically rather than using numerical approximations. Can we rely on the calculated result from Wolfram, especially if almost all the addends are irrational, or must the students eventually prove it mathematically? It is clear that the problem can be solved using software; however, the nature of the result raises questions about its correctness, and this inherent informality can encourage a few students to seek viable mathematical proofs. In this way, a balance is reached between formal and informal mathematics.

Scrutinizing the Expanding Scope of Geographical Indication Protection: A Critical Analysis of the Justifications for the Anti-Evocation Measures

AbstractThe global trend towards heightened protection for geographical indications (GIs) has been bolstered by the incorporation of anti-evocation provisions in various bilateral and regional trade agreements, primarily led by the European Union (EU). While these anti-evocation measures have raised GI protection to an unprecedented level, they also place limitations on the freedom of expression and competition for other market players. This article conducts a critical analysis of the necessity of those restrictions by evaluating the justifications for implementing anti-evocation protection. Specifically, the analysis centres on the formal justifications put forth by law enforcement authorities and their direct contribution to enforcement errors and inconsistencies. Furthermore, inherent limitations within these justifications are also identified. Clarifying the rationale for anti-evocation protection and establishing a clearly defined scope of protection, substantiated by sound justifications, could effectively mitigate errors and inconsistencies in law enforcement and minimize any undue impact on the public interest. Countries that have adopted or are considering adopting anti-evocation protection, following the EU's lead, should exercise caution to avoid similar pitfalls.

Market selection and learning under model misspecification

This paper studies market selection in an Arrow-Debreu economy with complete markets where agents learn over misspecified models. In this setting, standard Bayesian learning loses its formal justification and biased learning processes may provide a selection advantage. Studying two cases of model misspecification and four learning processes, our analysis reveals that, differently from correctly specified settings, the ecology of traders populating the market crucially affects selection dynamics and, thus, long-run asset valuation. In fact, model misspecification implies a general difficulty in ranking learning behaviors with respect to their survival prospects. For instance, prediction averaging shows an advantage when the true data generating process belongs to the same family of models that agents use to learn. This advantage partially disappears when the true model belongs to a more general class, as a trade off emerges between approximating the projection of the true model on the space on which the agents learn and adapting to the part of the true model that cannot be represented in that space. Rules that guarantee survival are possible, but they exploit imitative mechanisms that require information about all the other market participants.

Argumentation and explanation in the law.

This article investigates the conceptual connection between argumentation and explanation in the law and provides a formal account of it. To do so, the methods used are conceptual analysis from legal theory and formal argumentation from AI. The contribution and results are twofold. On the one hand, we offer a critical reconstruction of the concept of legal argument, justification, and explanation of decision-making as it has been elaborated in legal theory and, above all, in AI and law. On the other hand, we propose some definitions of explanation in the context of formal legal argumentation, showing a connection between formal justification and explanation. We also investigate the notion of stable normative explanation developed elsewhere in Defeasible Logic and extend some complexity results. Our contribution is thus mainly conceptual, and it is meant to show how notions of explanation from literature on explainable AI and legal theory can be modeled in an argumentation framework with structured arguments.

Simple interpolations of inflation expectations

In this paper, I address the issue of using fixed-event forecasts to track the evolution of rolling-event forecasts. This paper supplies a formal justification for the procedure of approximating rolling-event forecasts by averaging two fixed-event forecasts. I illustrate the methods with the computation of inflation expectations at various horizons.

ЕФЕКТИВНІСТЬ ЗАХИСТУ ПРАВ ТА ІНТЕРЕСІВ ОСІБ СУДАМИ У СФЕРІ ФІНАНСОВОГО КОНТРОЛЮ ЯК ПІДСТАВА ОБМЕЖЕННЯ СУДОВОЇ ЮРИСДИКЦІЇ

The tasks of the article are to characterize the main law enforcement positions on the certain issues of financial control in Ukraine and to identify both positive and negative consequences for the formulation of scientifically based proposals for amendments. The judicial practice of Ukraine in law enforcement consistently defends the principle of «self-limitation» of jurisdiction by recognizing as not subject to consideration and resolution by the courts a number of lawsuits, the applied methods of protection in which will not ensure effective protection of the rights, freedoms and interests of individuals. The formal justification of this concept in the field of state financial control does not provide sufficient grounds for unquestionably agreeing with its application, because as a result, a person is in legal uncertainty for a long time regarding the final legal assessment of the results of his/her activities by a supervisory body, with which he/she does not agree. The idea of gradually postponing the resolution of the dispute about the results of control activities at the next stages of the procedure in practice turns into the lack of an opportunity for operational protection of the person, the complication of the subject of proof in the framework of court proceedings, which does not correspond to the principles of procedural economy. It is in these conditions that a violation of the guarantees of the right to an effective means of protection in the national legal system (Article 13 of the Convention for the Protection of Human Rights and Fundamental Freedoms) should be established, since the exclusion of the court’s jurisdiction leads to the actual leveling of the content of the right to a fair trial and legal protection. And therefore, at least in the above categories of cases (regarding acts or other documents drawn up as a result of inspection (control) measures; claim of controlling authority for the compensation for damages as a result of the measures of state financial control; about factual and documentary grounds for carrying out the measures of state control in the financial sphere after admission to the inspection) there are normative and factual prerequisites for changing the practice in favor of the possibility of filing appropriate lawsuits and their consideration by administrative courts.

Game System Models: Toward Semantic Foundations for Technical Game Analysis, Generation, and Design

Game system models introduce abstractions over games in order to support their analysis, generation, and design. While excellent, models to date leave tacit what they abstract over, why they are ontologically adequate, and how they would be realized in the engine underlying the game. In this paper we model these abstraction gaps via the first-order modal mu-calculus. We use it to reify the link between engines to our game interaction model, a player-computer interaction framework grounded in the Game Ontology Project. Through formal derivation and justification, we contend our work is a useful code studies perspective that affords better understanding the semantics underlying game system models in general.

Active neck orthosis for musculoskeletal cervical disorders rehabilitation using a parallel mini-robotic device

This work presents the design, construction, simulation, instrumentation, and implementation of a closed chain robotic active neck orthosis with four degrees of freedom satisfying a similar configuration to a four-legged Stewart platform. The dynamics of the device is regulated by a robust control strategy with state restrictions based on a first sliding mode controller with state dependent gains that operates as a divergent function as the states approach the state restrictions. The formal justification about the application of the controller on the proposed orthosis, the finite-time convergence to a sliding surface and the effect of the constraints is proven. The orthosis is also controlled with a traditional state feedback strategy to evaluate the tracking error concerning an external disturbance and compare its performances against the proposed control strategy. A graphical interface based on computer vision is developed to select the type of therapy and assess the patient’s range of motion while wearing the orthosis. The system is tested in some selected volunteers subjects, managing to limit the range of motion within a pre-established area based on the range of motion reported by patients with cervicalgia and whiplash syndrome found in the literature. The developed system offers a novel method to deal with the treatment of neck illnesses based on a novel mechatronic device.

Volume extrapolation via eigenvector continuation

We develop an extension of eigenvector continuation (EC) that makes it possible to extrapolate simulations of quantum systems in finite periodic boxes across large ranges of box sizes. The formal justification for this approach, which we call finite-volume eigenvector continuation (FVEC), is provided by matching periodic functions at different box sizes. As concrete FVEC implementation we use a discrete variable representation based on plane-wave states and present several applications calculated within this framework.

Integrating rational functions of sine and cosine using the rules of Bioche

For integrals consisting of rational functions of sine and cosine a set of little known rules known as the Bioche rules are considered. The rules, which consist of testing the differential form of the integral for invariance under one of three simple substitutions , and , allow one to decide which of the three trigonometric substitutions of: , or would be most appropriate for finding the integral. In seeking to not only bring these simple rules to the attention of a wider audience, formal justification of the rules is provided and two examples illustrating the use of the rules given.

A chemical thermodynamic model of motor enzymes unifies chemical-Fx and powerstroke models

Molecular motors play a central role in many biological processes, ranging from pumping blood and breathing to growth and wound healing. Through motor-catalyzed chemical reactions, these nanomachines convert the chemical free energy from ATP hydrolysis into two different forms of mechanical work. Motor enzymes perform reversible work, wrev, through an intermediate step in their catalyzed reaction cycle referred to as a working step, and they perform Fx work when they move a distance, x, against a force, F. In a powerstroke model, wrev is performed when the working step stretches a spring within a given motor enzyme. In a chemical-Fx model, wrev is performed in generating a conserved Fx potential defined external to the motor enzyme. It is difficult to find any common ground between these models even though both have been shown to account for mechanochemical measurements of motor enzymes with reasonable accuracy. Here, I show that, by changing one simple assumption in each model, the powerstroke and chemical-Fx model can be reconciled through a chemical thermodynamic model. The formal and experimental justifications for changing these assumptions are presented. The result is a unifying model for mechanochemical coupling in motor enzymes first presented by A.V. Hill in 1938 that is consistent with single-molecule structural and mechanical data.

The Epistemology of Machine Learning

This paper argues that machine learning is a knowledge-producing enterprise, since we are increasingly relying on artificial intelligence. But the knowledge discovered by machine is completely beyond human experience and human reason, becoming almost incomprehensible to humans. I argue that standard calls for interpretability that focus on the epistemic inscrutability of black-box machine learning may be misplaced. The problems of transparency and interpretability of machine learning stem from how we perceive the possibility of ‘machine knowledge’. In other words, the justification for machine knowledge does not need to include transparency and interpretability. Therefore, I am going to examine some sort of machine learning epistemology and provide three possible justifications for machine knowledge, which are formal justification, model justification and practical justification.

중학교 증명 수업에서 학생들의 연역적 추론 분석: 의사소통(commognition) 관점을 중심으로1)

This study developed a teaching-learning method by focusing on the deductive reasoning and analyzed the characteristics of mathematical discourse in the light of the framework descriptors of the level of mathematical justification based on Sfard’s commognition perspective, in order to provide the implication for proof teaching by encouraging students to experience deductive reasoning as a thinking process. To achieve the aim, 8 lessons were implemented using the teaching-learning method developed by this study and the students’ features related to deductive reasoning were explored based on the descriptors. As a result, at the lessons about the mathematical justification there was a commognitive conflict between students using empirical justification and deductive justification, in the process of checking premises for deductive justification, students reached axiomatic-formal justification with partial and procedural characteristics. At the lessons of implementing mathematical justification for the properties of parallelogram, the students made a chaining relationships by eliciting conclusions from the premises, connected several steps of justification, and defined by the deductive organization of properties. It can be said that they used the meta-rule of axiomatic- formal justification. The result suggests that deductive reasoning could be taught to middle school students by taking appropriate pedagogical strategies. In the process of justifying, students realized the existence of axiom and its meaning as a promise, understood the chaining relationships derived from axioms. In addition, in the process of justifying visual mediators were used an important tool that drove deductive reasoning and the terms ‘proof’ and ‘definition’ were informally emerged even though have not been taught at the lessons.

Shapley Meets Uniform: An Axiomatic Framework for Attribution in Online Advertising

One of the central challenges in online advertising is attribution, namely, assessing the contribution of individual advertiser actions such as emails, display ads, and search ads to eventual conversion. Several heuristics are used for attribution in practice; however, most do not have any formal justification. The main contribution in this work is to propose an axiomatic framework for attribution in online advertising. We show that the most common heuristics can be cast under the framework and illustrate how these may fail. We propose a novel attribution metric, which we refer to as counterfactual adjusted Shapley value (CASV), which inherits the desirable properties of the traditional Shapley value while overcoming its shortcomings in the online advertising context. We also propose a Markovian model for the user journey through the conversion funnel, in which ad actions may have disparate impacts at different stages. We use the Markovian model to compare our metric with commonly used metrics. Furthermore, under the Markovian model, we establish that the CASV metric coincides with an adjusted “unique-uniform” attribution scheme. This scheme is efficiently implementable and can be interpreted as a correction to the commonly used uniform attribution scheme. We supplement our theoretical developments with numerical experiments using a real-world large-scale data set. This paper was accepted by David Simchi-Levi, revenue management and market analytics.