Restricted Version Research Articles

Once-Marking and Always-Marking 1-Limited Automata

Single-tape nondeterministic Turing machines that are allowed to replace the symbol in each tape cell only when it is scanned for the first time are also known as [Formula: see text]-limited automata. These devices characterize, exactly as finite automata, the class of regular languages. However, they can be extremely more succinct. Indeed, in the worst case, the size gap from [Formula: see text]-limited automata to one-way deterministic finite automata is double exponential. Here we introduce two restricted versions of [Formula: see text]-limited automata, once-marking[Formula: see text]-limited automata and always-marking[Formula: see text]-limited automata, and study their descriptional complexity. We prove that once-marking [Formula: see text]-limited automata still exhibit a double exponential size gap to one-way deterministic finite automata. However, their deterministic restriction is polynomially related in size to two-way deterministic finite automata, in contrast to deterministic [Formula: see text]-limited automata, whose equivalent two-way deterministic finite automata in the worst case are exponentially larger. For always-marking [Formula: see text]-limited automata, we prove that the size gap to one-way deterministic finite automata is only a single exponential. The gap remains exponential even in the case the given machine is deterministic. We obtain other size relationships between different variants of these machines and finite automata and we present some problems that deserve investigation.

Sparse and inconsistent reporting of pre- and post-operative radiographic angles of total knee arthroplasty using true unrestricted kinematic alignment: An umbrella review and secondary meta-analysis.

To identify, synthesise and critically appraise findings of systematic reviews and meta-analyses on pre- and post-operative radiographic angles (lateral distal femoral angle [LDFA], medial proximal tibial angle [MPTA] and hip-knee-ankle [HKA] angle) of unrestricted kinematic alignment versus mechanical alignment in total knee arthroplasty (TKA). Two authors searched MEDLINE, EMBASE and Epistemonikos for systematic reviews, with or without meta-analyses, that reported on TKA outcomes using unrestricted kinematic alignment. The methodological quality of the included systematic reviews and meta-analyses was independently assessed using A MeaSurement Tool to Assess systematic Reviews (AMSTAR-2). The effect size with its 95% confidence interval (CI) for radiographic angles was extracted from the systematic reviews and meta-analyses. The characteristics of clinical studies included in systematic reviews were listed and tabulated. Pre- and post-operative MPTA, LDFA and HKA angles were summarised using meta-analytic random-effects models. Nineteen records were eligible for data extraction. Systematic reviews and meta-analyses included 44 clinical studies, of which 31 were on unrestricted kinematic alignment and 13 were on restricted versions of kinematic alignment. None of the included systematic reviews or meta-analyses fulfiled all seven critical AMSTAR-2 domains. Few comparative studies reported both pre- and post-operative angles (LDFA, n = 3; MPTA, n = 4; and HKA angle, n = 10). Mean pre- and post-operative LDFAs were 88.0° (range, 83-94°) and 88.0° (range, 80-96°) for the kinematic alignment group, and 88.2° (range, 83-95°) and 90.2° (range, 84-97°) for the mechanical alignment group. Mean pre- and post-operative MPTAs were 86.0° (range, 78-93°) and 87.1° (range, 78-94°) for the kinematic alignment group and 86.4° (range, 77-94°) and 89.6° (range, 84-95°) for the mechanical alignment group. Mean pre- and post-operative HKA angles were -3.3° (range, -24° to 24°) and -0.3° (range, -10° to 8°) for the kinematic alignment group and -6.9° (range, -25° to 7°) and -0.9° (range, -8° to 7°) for the mechanical alignment group. Most systematic reviews and meta-analyses that report outcomes of TKA using kinematic alignment do not distinguish between the different versions of kinematic alignment. The clinical studies included in systematic reviews are limited and inconsistent in their reporting of radiographic angles. Different alignment strategies are often grouped under the umbrella term of kinematic alignment, which contributes to conflicting reports, confusion and unresolved questions regarding the efficacy of true unrestricted kinematic alignment. Level IV.

A Note on Gödel’s First Disjunct Formalised in DTK System

This note clarifies the significance of the proof of Gödel’s first disjunct obtained through the formalisation of Penrose’s second argument within the DTK system. It analyses two formulations of the first disjunct – one general and the other restricted – and dwells on the demonstration of the restricted version, showing that it yields the following result: if by F we denote the set of propositions derivable from any formalism and by K the set of mathematical propositions humanly knowable, then, given certain conditions, F necessarily differs from K. Thus it is possible that K surpasses F but also, on the contrary, that F surpasses K. In the latter case, however, the consistency of F is humanly undecidable.

Algorithms for the thief orienteering problem on directed acyclic graphs

We consider the scenario of routing an agent called a thief through a weighted graph G=(V,E) from a start vertex s to an end vertex t. A set I of items each with weight wi and profit pi is distributed among V∖{s,t}. The thief, who has a knapsack of capacity W, must follow a simple path from s to t within a given time T while packing in the knapsack a set of items taken from the vertices along the path of total weight at most W and maximum profit. The travel time across an edge depends on the edge length and current knapsack load.The thief orienteering problem (ThOP) is a generalization of the orienteering problem, the longest path problem, and the 0-1 knapsack problem. We prove that there exists no approximation algorithm for ThOP with constant approximation ratio unless P=NP, and we present a polynomial-time approximation scheme (PTAS) for a relaxed version of ThOP when G is directed and acyclic that produces solutions that use time at most T(1+ϵ) for any constant ϵ>0. We also present a fully polynomial-time approximation scheme (FPTAS) for ThOP on arbitrary undirected graphs where the travel time depends only on the lengths of the edges and T is the length of a shortest path from s to t plus a constant K. Finally, we present a FPTAS for a restricted version of the problem where the input graph is a clique.

Long-Run Impacts of an Early-life Nutrition Program: Evidence from the Introduction of the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC).

To study how access to the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) during the prenatal and early childhood periods affects long-term health outcomes of the affected cohorts. In order to identify the effects of the WIC program, we exploit variations in the timing of its introduction in different counties and analyze future health indicators of affected cohorts. We use the restricted version of the Panel Study of Income Dynamics, which includes county-level identifiers through the interview year 2019. Our findings suggest that extending WIC access by one month correlates with a 0.2-0.3% point decrease in asthma incidence (p < 0.1 to p < 0.01) of affected cohorts. Although the connection between WIC and asthma is not fully understood, existing studies suggest potential pathways. Micronutrient deficiencies during early life can impact immune function and inflammation, both relevant to asthma. Moreover, adopting healthier dietary habits may improve microbiome composition, lowering asthma risk. Other indirect benefits of WIC, such as increased use of preventive healthcare services, may also contribute to the prevention of asthma. Despite uncertainties, these estimates remain robust across various model specifications. Our study implies that early-life nutritional support programs such as WIC may alleviate the burden of asthma, although the specific mechanisms and effect sizes remain unclear. Given the substantial impact of asthma in the U.S., our findings underscore the potential long-term benefits of early-life nutritional support programs for lifelong health.

Assessing the Effectiveness of an mHealth Intervention to Support Men Who Have Sex With Men Engaging in Chemsex (Budd): Single-Case and Pre-Post Experimental Design Study.

This study focuses on the Budd app, a mobile health intervention designed for gay, bisexual, and other men who have sex with men who participate in chemsex. Chemsex, the use of psychoactive drugs in a sexual context, presents substantial health risks including increased HIV transmission and mental health issues. Addressing these risks requires innovative interventions tailored to the unique needs of this population. This study aims to evaluate the effectiveness of the Budd app in promoting drug harm reduction practices among its users, focusing on knowledge, behavioral intention, risk behavior awareness, and self-efficacy. The study used a mixed methods approach, combining a single-case experimental design and a pre-post study. A total of 10 participants from an outpatient clinic were recruited, and each attended the clinic 3 times. During the first visit, participants installed a restricted version of the Budd app, which allowed them to report daily mood and risk behavior after chemsex sessions. Phase A (baseline) lasted at least 2 weeks depending on chemsex participation. In the second visit, participants gained full access to the Budd app, initiating phase B (intervention). Phase B lasted at least 6 weeks, depending on chemsex participation, with identical data input as phase A. Participants completed pre- and postintervention surveys assessing behavioral determinants during the first and third visit. The study observed an increased knowledge about chemsex substances postintervention, with a mean percentage improvement in knowledge scores of 20.59% (SD 13.3%) among participants. Behavioral intention and self-efficacy showed mixed results, with some participants improving while others experienced a decrease. There was also a variable impact on awareness of risk behavior, with half of the participants reporting a decrease postintervention. Despite these mixed results, the app was generally well-received, with participants engaging with the app's features an average of 50 times during the study. The Budd app showed effectiveness in enhancing knowledge about chemsex substances among gay, bisexual, and other men who have sex with men. However, its impact on safe dosing behavior, behavioral intention, self-efficacy, and risk behavior awareness was inconsistent. These findings suggest that while educational interventions can increase knowledge, translating this into behavioral change is more complex and may require more participants, a longer follow-up period, and additional strategies and support mechanisms.

An argument for moral evidentialism

AbstractMoral evidentialism is the view that one ought morally to believe only what is suggested by the evidence at one's disposal. As announced in the title, an argument for (a slightly restricted version of) this view is presented. The argument crucially relies on two specific links between belief and assertion, namely that one should not believe what one must not assert, and that one must not assert what is not suggested by the evidence at one's disposal. In both cases, the normativity involved is moral. The links are established, and it is shown how to deal with seemingly apparent counterexamples.

Automatic for the (tax) people: information sharing and cross-border investment in tax havens

Summary This paper examines the impact of international automatic exchange of information (AEOI) treaties on cross-border investments in tax havens. Using a restricted version of the BIS Locational Banking Statistics, we find that AEOIs significantly reduced cross-border deposits. A sectoral breakdown assessment reveals that households were the key driving force behind this contraction. However, we also document evidence of households’ deposits shifting to non-AEOI haven countries and larger deposits by non-bank financial institutions between tax haven countries, suggesting an increased use of shell corporation networks since AEOI introduction. Extending the analysis to portfolio and direct investment, we observe that changes in investment patterns vis-à-vis tax havens are consistent with a significant impact of AEOI treaties on these forms of cross-border investment.

An Efficient Algorithm for Solving the 2-MAXSAT Problem

In the maximum satisfiability (MAXSAT) problem, we are given a set V of m variables and a collection C of n clauses over V. We will seek a truth assignment to maximize the number of satisfied clauses. This problem is NP-hard even for its restricted version, the 2-MAXSAT problem, in which every clause contains at most two literals. In this paper, we discuss an efficient algorithm to solve this problem. Its worst-case time complexity is bounded by . In the case that log2 nm is bounded by a constant, our algorithm is a polynomial algorithm. In terms of Garey and Johnson, any satisfiability instance can be transformed to a 2-MAXSAT instance in polynomial time. Thus, our algorithm may lead to a proof of P = NP.

A Simple Perspective on Simultaneous Column and Row Generation

To solve a linear programming problem with many variables and constraints, a simultaneous column and row generation algorithm can be used. Such an algorithm iteratively solves a restricted version of a linear programming problem including only a subset of the variables and constraints. In each iteration, it might simultaneously add both a new variable and constraint, as opposed to non-simultaneous column and row generation algorithms that only add either a new variable or constraint. In this paper, a simple perspective is provided to indicate the relevance of simultaneous column and row generation and to make it more accessible. Particular emphasis is put on an optimality condition for linear programming which is perhaps a particular source of confusion in this context. It is argued that optimality can be achieved using non-simultaneous column and row generation algorithms, while an example is provided illustrating the potential computational gains of using simultaneous column and row generation algorithms.

Dynamic retrieval of events and associations from memory: An integrated account of item and associative recognition.

Memory theories distinguish between item and associative information, which are engaged by different tasks: item recognition uses item information to decide whether an event occurred in a particular context; associative recognition uses associative information to decide whether two events occurred together. Associative recognition is slower and less accurate than item recognition, suggesting that item and associative information may be represented in different forms and retrieved using different processes. Instead, I show how a dynamic model (Cox & Criss, 2020; Cox & Shiffrin, 2017) accounts for accuracy and response time distributions in both item and associative recognition with the same set of representations and processes. Item and associative information are both represented as vectors of features. Item and associative recognition both depend on comparing traces in memory with probes of memory in which item and associative features gradually accumulate. Associative features are slower to accumulate, but largely because they emerge from conjunctions of already-accumulated item features. I apply the model to data from 453 participants, each of whom performed an item and performed associative recognition following identical study conditions (Cox et al., 2018). Comparisons among restricted versions of the model show that its account of associative feature formation, coupled with limits on the rate at which features accumulate from multiple items, explains how and why the dynamics of associative recognition differ from those of item recognition even while both tasks rely on the same underlying representations. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

On the sources of the aggregate risk premium: Risk aversion, bubbles or regime-switching?

We develop and estimate a consumption-based asset pricing model that uses historical US financial data and assumes recursive utility, allowing for priced regime-switching risk and intrinsic bubbles. We also estimate several restricted versions, including only a subset of these features. Priced regime-switching risk is essential to the equity risk premium, explaining more than fifty per cent of it. Furthermore, a model that does not consider regime switching would overestimate the public's risk aversion, mistakenly assigning the observed risk premium to high-risk aversion instead of priced regime-switching. We also find that intrinsic bubbles are statistically significant, and even though they are not crucial in explaining the risk premium, they substantially improve the model's fit at the end of the sample.

Collective Knowledge and the Limits of the Expanded Identification Doctrine

Abstract The Economic Crime and Corporate Transparency Act 2023 expanded the identification doctrine in welcome ways, but, I argue, does not go far enough. Specifically, I contend that the Act’s reforms do not sufficiently respond to the threat of senior managers who culpably interfere in the proper flow of information within the company to orchestrate harmful or risky practices by others, all while seeking to avoid liability by preventing any individual from forming the full mens rea of any economic crime. How should the criminal law respond to this gap? I argue it would be problematic to respond by extending individual liability even further—say, by expanding the already ‘disturbingly wide’ inchoate offences in the Serious Crime Act 2007. Instead, the collective knowledge doctrine provides a tailor-made solution to these scenarios. This doctrine would permit courts (in narrow circumstances) to aggregate individuals’ mental states within the company to construct a distinct corporate mens rea. I argue that section 196 of the 2023 Act, which expands the identification doctrine, could be read to incorporate a narrow version of the collective knowledge doctrine—at least if courts are willing to adopt a purposivist orientation aimed at giving effect to the wider aims of Parliament. A restricted version of the collective knowledge doctrine would have normative benefits and so, I suggest, is worth putting to the courts through test litigation.

Synchronous Dynamical Systems on Directed Acyclic Graphs: Complexity and Algorithms

Discrete dynamical systems serve as useful formal models to study diffusion phenomena in social networks. Several recent articles have studied the algorithmic and complexity aspects of some decision problems on synchronous Boolean networks, which are discrete dynamical systems whose underlying graphs are directed, and may contain directed cycles. Such problems can be regarded as reachability problems in the phase space of the corresponding dynamical system. Previous work has shown that some of these decision problems become efficiently solvable for systems on directed acyclic graphs (DAGs). Motivated by this line of work, we investigate a number of decision problems for dynamical systems whose underlying graphs are DAGs. We show that computational intractability (i.e., PSPACE -completeness) results for reachability problems hold even for dynamical systems on DAGs. We also identify some restricted versions of dynamical systems on DAGs for which reachability problem can be solved efficiently. In addition, we show that a decision problem (namely, Convergence), which is efficiently solvable for dynamical systems on DAGs, becomes PSPACE -complete for Quasi-DAGs (i.e., graphs that become DAGs by the removal of a single edge). In the process of establishing the above results, we also develop several structural properties of the phase spaces of dynamical systems on DAGs.

The (changing) concept of democracy in (transforming) European populist radical right discourses: the case of Polish Law and Justice

ABSTRACT The populist radical right (PRR) has been actively engaged in the discursive struggle over the notion of democracy in Europe and beyond. This article examines how in practice PRR parties discursively construct and manipulate the concept of democracy. By taking a longitudinal comparative perspective on the political discourse of Jarosław Kaczyński, the leader of the Polish Law and Justice (PiS) party, in five consecutive electoral campaigns between 2007 and 2023, the article identifies key discursive strategies used to construct PRR conceptions of democracy. The analysis of PiS’s discourse in government and opposition shows that the PRR strives to fully appropriate the concept of democracy: when in power, the PRR discursively constructs (preserving) democracy as inseparable from the political status quo; while in opposition, it conditions (restoring) democracy with its accession to power. Despite numerous references to majoritarian conceptions of democracy and plebiscitary mechanisms and its claims to promote a radical democratic renewal, the PRR tends not to question the underlying principles of parliamentary representation. In practice, it discursively constructs a severely restricted version of democracy in which democratic participation essentially boils down to participation in elections. Hence, references to democracy are primarily used by the PRR to (emotionally) mobilise voters.

Fixed parameter tractable algorithms for watchman route related problems on line segment arrangements

In this paper, we study the parameterized complexity of some variants of the watchman route problem on line segment arrangements. We show that finding a minimum length Watchman Tree/Route on line Segment arrangements (WTS/WRS) is Fixed Parameter Tractable (FPT) with respect to the number of vertices in the tree/route as the parameter. We then prove that another variant of WTS referred to as Minimum Corridor Connection (MCC), is FPT with respect to the number of regions as the parameter. We also consider WRS with the link distance metric (LWRS) and propose an FPT algorithm for a restricted version in which each line segment in the input arrangement has a bound on the number of intersections it makes with other segments in the arrangement.

Constrained inference in scaled mixed effects models with applications to London Junior School Project data

Multiple outcomes arise frequently in many different settings. Mixed effect models are a useful tool for the analyses of such data. However, when outcomes are measured on different scales, analyses based on any one scale are misleading. Often parameters of the model are subject to known order restrictions. To incorporate heterogeneity across different outcomes, we propose a scaled linear mixed effect model. To estimate parameters, we propose a maximum likelihood estimation procedure based on a restricted version of the expectation-conditional maximization either algorithm. Constrained hypotheses testing procedures are developed using likelihood ratio tests. The empirical significance levels and powers are studied using simulations. This article shows that incorporating the restrictions improves the mean squared errors of the estimates and the power of the tests. The methodology is applied on the London Junior School Project data incorporating known restrictions of patterns of scores. Journal of Statistical Research 2023, Vol 57, No.1-2, pp.81-94

ASYMPTOTICALLY UNIFORMLY MOST POWERFUL TESTS FOR UNIT ROOTS IN GAUSSIAN PANELS WITH CROSS-SECTIONAL DEPENDENCE GENERATED BY COMMON FACTORS

This paper considers testing for unit roots in Gaussian panels with cross-sectional dependence generated by common factors. Within our setup, we can analyze restricted versions of the two prevalent approaches in the literature, that of Moon and Perron (2004, Journal of Econometrics 122, 81–126), who specify a factor model for the innovations, and the PANIC setup proposed in Bai and Ng (2004, Econometrica 72, 1127–1177), who test common factors and idiosyncratic deviations separately for unit roots. We show that both frameworks lead to locally asymptotically normal experiments with the same central sequence and Fisher information. Using Le Cam’s theory of statistical experiments, we obtain the local asymptotic power envelope for unit-root tests. We show that the popular Moon and Perron (2004, Journal of Econometrics 122, 81–126) and Bai and Ng (2010, Econometric Theory 26, 1088–1114) tests only attain the power envelope in case there is no heterogeneity in the long-run variance of the idiosyncratic components. We develop a new test which is asymptotically uniformly most powerful irrespective of possible heterogeneity in the long-run variance of the idiosyncratic components. Monte Carlo simulations corroborate our asymptotic results and document significant gains in finite-sample power if the variances of the idiosyncratic shocks differ substantially among the cross-sectional units.

A variance-based optimization for determining ground and excited N-electron wave functions within the doubly occupied configuration interaction scheme.

This work describes optimizations of N-electron system wave functions by means of the simulated annealing technique within the doubly occupied configuration interaction framework. Using that technique, we minimize the energy variance of a Hamiltonian, providing determinations of wave functions corresponding to ground or excited states in an identical manner. The procedure that allows us to determine electronic spectra can be performed using treatments of restricted or unrestricted types. The results found in selected systems, described in terms of energy, spin, and wave function, are analyzed, showing the performance of each method. We also compare these results with those arising from more traditional approaches that minimize the energy, in both restricted and unrestricted versions, and with those obtained from the full configuration interaction treatment.

Resolving to believe: Kierkegaard's direct doxastic voluntarism

AbstractAccording to a traditional interpretation of Kierkegaard, he endorses a strong form of direct doxastic voluntarism on which we can, by brute force of will, make a “leap of faith” to believe propositions that we ourselves take to be improbable and absurd. Yet most leading Kierkegaard scholars now wholly reject this reading, instead interpreting Kierkegaard as holding that the will can affect what we believe only indirectly. This paper argues that Kierkegaard does in fact endorse a restricted, sophisticated, and plausible version of direct doxastic voluntarism. On Kierkegaard's view, when we take ourselves to be in an epistemically permissive situation, we have the ability to form outright beliefs (but not credences) at will in virtue of our ability to voluntarily 1) open or close inquiry and 2) determine our attitude towards epistemic risk.