Showing papers presented at "Conference on Computability in Europe in 2011"
01 Jul 2011
TL;DR: The game here proposed collects and processes information about the accessibility of city roads to build paths that may be approached by people with impairments and is rewarded by gaining points and positions in the game ranking for each reliable piece of information they provide.
Abstract: Computer games today represent one of the most important businesses in the IT industry, as well as one of the prominent means of entertainment chosen by children and adults. Their popularity in the contemporary world society has led many researchers to think how they could be put to good use to improve the education of players engaged in a game. In this work we present a game that goes beyond this paradigm, which is centered on single persons and pervasively relies on players to pursue a service that may be useful to a community as a whole. The game we here propose collects and processes information about the accessibility of city roads to build paths that may be approached by people with impairments. Players that join the game are rewarded by gaining points and positions in the game ranking for each reliable piece of information they provide. Accessible paths, built taking into account such information, can be accessed through a Google Maps-like service which computes the shortest and safest path, for a person with a certain degree of disability, between any two given origin-destination points.
41 citations
01 Apr 2011
TL;DR: The CALSIUM framework to elicit children's contributions and perspectives in the design of an online game for enhancing social skills of children was described and the children's cognitive understanding of social knowledge was enhanced, evident from the design artifacts produced.
Abstract: In this article we describe the CALSIUM framework to elicit children's contributions and perspectives in the design of an online game for enhancing social skills of children This study advocates a participatory design approach that emphasizes the active involvement of users at the early part of the design process The children play-tested the game prototype and participated in focus group discussions Using storyboarding, a low-fidelity prototyping technique, they developed design concepts and ideas which were translated into design directions for the development of the game The data collected were used to glean insights into the likes and dislikes of children and to analyze the opportunities and challenges in engaging children as users, testers, informants, and design partners Besides stretching children's creativity and critical thinking on the game design, the children's cognitive understanding of social knowledge was enhanced, evident from the design artifacts produced
41 citations
27 Jun 2011
TL;DR: This work investigates whether the same is true in the probabilistic case of cellular automata, which consists of an bi-infinite array of identical cells, each of which may take one of a finite number of possible sstates.
Abstract: Cellular automata (CAs) consist of an bi-infinite array of identical cells, each of which may take one of a finite number of possible sstates. The entire array evolves in discrete time steps by iterating a global evolution G. Further, this global evolution G is required to be shift-invariant (it acts the same everywhere) and causal (information cannot be transmitted faster than some fixed number of cells per time step). At least in the classical [7], reversible [11] and quantum cases [1], these two top-down axiomatic conditions are sufficient to entail more bottom-up, operational descriptions of G. We investigate whether the same is true in the probabilistic case.
20 citations
01 Jul 2011
TL;DR: Liquid Interfaces uses the physical qualities of ferromagnetic fluids in combination with capacitive, multi-touch technology, to produce a 3D,Multi-touch interface where actuation, representation, and self-configuration occur through the malleable liquid, ferromeagnetic fluid.
Abstract: We present a new methodology based on ferromagnetic fluids in which the user can have direct interaction (input/output) through a tangible and malleable interface. Liquid Interfaces uses the physical qualities of ferromagnetic fluids in combination with capacitive, multi-touch technology, to produce a 3D, multi-touch interface where actuation, representation, and self-configuration occur through the malleable liquid, ferromagnetic fluid. This, combined with the ability to produce sound, enables users to create musical sculptures that can be morphed in real time by interacting directly with the ferromagnetic fluid.
20 citations
01 Apr 2011
TL;DR: A large-scale study for CAPTCHAs' usability without the resource overhead required by traditional survey-based studies is conducted and a consistent and reliable metric for assessing usability is proposed.
Abstract: CAPTCHA is an effective and widely used solution for preventing computer programs (i.e., bots) from performing automated but often malicious actions, such as registering thousands of free email accounts or posting advertisement on Web blogs. To make CAPTCHAs robust to automatic character recognition techniques, the text in the tests are often distorted, blurred, and obscure. At the same time, those robust tests may prevent genuine users from telling the text easily and thus distribute the cost of crime prevention among all the users. Thus, we are facing a dilemma, that is, a CAPTCHA should be robust enough so that it cannot be broken by programs, but also needs to be easy enough so that users need not to repeatedly take tests because of wrong guesses. In this article, we attempt to resolve the dilemma by proposing a human computation game for quantifying the usability of CAPTCHAs. In our game, DevilTyper, players try to defeat as many devils as possible by solving CAPTCHAs, and player behavior in completing a CAPTCHA is recorded at the same time. Therefore, we can evaluate CAPTCHAs' usability by analyzing collected player inputs. Since DevilTyper provides entertainment itself, we conduct a large-scale study for CAPTCHAs' usability without the resource overhead required by traditional survey-based studies. In addition, we propose a consistent and reliable metric for assessing usability. Our evaluation results show that DevilTyper provides a fun and efficient platform for CAPTCHA designers to assess their CAPTCHA usability and thus improve CAPTCHA design.
16 citations
27 Jun 2011
TL;DR: Here it is proved that recognizing synchronizing automata whose language of synchronizing words is finitely generated as a two-sided ideal in Σ*.
Abstract: A deterministic finite-state automaton A is said to be synchronizing if there is a synchronizing word, i.e. a word that takes all the states of the automaton A to a particular one. We consider synchronizing automata whose language of synchronizing words is finitely generated as a two-sided ideal in Σ*. Answering a question stated in [1], here we prove that recognizing such automata is a PSPACE-complete problem.
15 citations
01 Nov 2011
TL;DR: This work will share general but important experiences with Unity, particularly interesting for game developers in beginner's level, and emphasize some general principles, particularly with respect to rapid game development and constrained graphics.
Abstract: In this work, we describe our experiences with FunCopter, a casual game we have designed and implemented using Unity engine, suitable for portable devices. We emphasize some general principles, particularly with respect to rapid game development and constrained graphics. In addition to that, we present the main activities realized in each software engineering phase and the lessons we learned during its development. These descriptions include details from the initial concept to the fully realized, playable game. This work will share general but important experiences with Unity, particularly interesting for game developers in beginner's level.
14 citations
14 Nov 2011
TL;DR: New forms of user interaction must support personalized access to the content on the TV, that they must support security and privacy, and that they should enable new forms of connectivity for all devices used in the living room.
Abstract: The success of the next-generation of interactive TV systems will depend on the type and form of user interaction these systems can support. New services like social TV, direct image, and data up- and download from the set-top box, connectivity of the iTV system to the PC and other mobile media devices, pose the question of how to support security, privacy, and personalization. To investigate the (sometimes naive) concepts of users of what changes an interactive TV system will bring for their living room behaviors in terms of security and privacy, and how to support these aspects regarding user interaction, we set up two ethnographic studies. Study one investigated users' assumptions and ideas on the concepts of security, privacy, and personalization in households that did currently not use interactive TV. This allowed us to understand possible problems in terms of security and privacy before the introduction of interactive TV. Study two investigated current practices and usages of media and devices, to understand what type of interaction concept would support the practices of the user best. The results show that new forms of user interaction must support personalized access to the content on the TV, that they must support security and privacy, and that they should enable new forms of connectivity for all devices used in the living room.
13 citations
01 Apr 2011
TL;DR: It is shown that a relatively simple sensor network configuration can enforce proper form and ensure that the player is actively participating in the game context, while a larger configuration can be used in training applications.
Abstract: We have created and tested a wearable sensor network that detects a user's body position and motion as input for interactive applications. It is envisioned to take game experiences such as Dance Dance Revolution, Wii Fit, and other active play scenarios to a whole new level, augmenting or replacing the binary foot-pad and balance board with a more immersive, full-body input system. We describe the design and functionality of the sensor network to characterize and verify body pose and position, perform experiments, and report on the capabilities and limitations of such a system. Our experience shows that a distributed set of sensors around the body prevents the player from cheating the system by using motion of the device alone to trick the system. In this work we show that a relatively simple sensor network configuration can enforce proper form and ensure that the player is actively participating in the game context, while a larger configuration can be used in training applications.
12 citations
27 Jun 2011
TL;DR: The structure of Wadge degrees of ω-regular k-partitions is characterized, the decidability of any level of the corresponding hierarchy is proved, and coincidence of the reducibilities by continuous functions and by functions computed by finite automata on the ω, regular k- partitions is established.
Abstract: We develop the theory of ω-regular k-partitions (for arbitrary k ≥ 2) that extends the theory around the Wagner hierarchy of regular ω-languages. In particular, we characterize the structure of Wadge degrees of ω-regular k-partitions, prove the decidability of any level of the corresponding hierarchy, establish coincidence of the reducibilities by continuous functions and by functions computed by finite automata on the ω-regular k-partitions.
11 citations
27 Jun 2011
TL;DR: The present work studies the learnability of automatic families by automatic learners which, in each round, output a hypothesis and update a long term memory, depending on the input datum, via an automatic function, that is, via a function whose graph is recognised by a finite automaton.
Abstract: Automatic classes are classes of languages for which a finite automaton can decide whether a given element is in a set given by its index. The present work studies the learnability of automatic families by automatic learners which, in each round, output a hypothesis and update a long term memory, depending on the input datum, via an automatic function, that is, via a function whose graph is recognised by a finite automaton. Many variants of automatic learners are investigated: where the long term memory is restricted to be the just prior hypothesis whenever this exists, cannot be of size larger than the size of the longest example or has to consist of a constant number of examples seen so far. Furthermore, learnability is also studied with respect to queries which reveal information about past data or past computation history; the number of queries per round is bounded by a constant. These models are generalisations of the model of feedback queries, given by Lange, Wiehagen and Zeugmann.
27 Jun 2011
TL;DR: In this article, a simpler algorithm based on a new partitioning scheme was proposed to test the consecutive ones property in time O(Σi=1m|ri|), all being involved.
Abstract: Let C be a finite set of n elements and R = {r1, r2, ..., rm} a family of m subsets of C. The family R verifies the consecutive ones property if there exists a permutation P of C such that each ri in R is an interval of P. Several algorithms have been proposed to test this property in time O(Σi=1m|ri|), all being involved. We present a simpler algorithm, based on a new partitioning scheme.
27 Jun 2011
TL;DR: This paper illustrates how the effectivity of the ergodic decomposition allows one to easily extend results from theErgodic case to the non-ergodic one (namely Poincare recurrence theorem) and shows that in some cases the er godic measures can be computed from the typical realizations of the process.
Abstract: The interaction between algorithmic randomness and ergodic theory is a rich field of investigation. In this paper we study the particular case of the ergodic decomposition. We give several positive partial answers, leaving the general problem open. We shortly illustrate how the effectivity of the ergodic decomposition allows one to easily extend results from the ergodic case to the non-ergodic one (namely Poincare recurrence theorem). We also show that in some cases the ergodic measures can be computed from the typical realizations of the process.
01 Nov 2011
TL;DR: A theoretical model developed, Playability for Acceptance and Adoption Model (PAAM) for conciseness, linking the antecedents into the key factors using information acquired from an extended literature review and a survey of online gamers showed that the “perceived benefits” construct is dependent on whether online games met gamers' goals for entertainment or leisure activities, in-game experiences, and out-game needs.
Abstract: New game technologies are changing the way people learn, play, socialize and participate in civic life. However, designing good games is challenging and expensive. While technologies have been improving swiftly, game design guidelines have evolved slowly. This article proposes a theoretical approach to study the key factors leading to successful online games. We first developed a theoretical model, Playability for Acceptance and Adoption Model (PAAM) for conciseness, linking the antecedents into the key factors using information acquired from an extended literature review. We then undertook a survey of 201 online gamers to investigate key factors affecting players' acceptance of online games. Through structural equation modeling, our findings showed that the “perceived benefits” construct is dependent on whether online games met gamers' goals for entertainment or leisure activities, in-game experiences, and out-game needs, while the “perceived ease of use” construct is determined by game design and facilitating conditions. We believe our theoretical model and results are useful to designers and developers of software companies when creating online games that will satisfy gamers' goals, in-game experiences, and out-game needs for playability.
27 Jun 2011
TL;DR: A number of theories of strength that of Π11- CA0 are identified, including the theory that the set of points attracted to the origin in a generalised transfinite dynamical system of any n-dimensional integer torus exists.
Abstract: We identify a number of theories of strength that of Π11- CA0. In particular: (a) the theory that the set of points attracted to the origin in a generalised transfinite dynamical system of any n-dimensional integer torus exists; (b) the theory asserting that for any Z ⊆ ω and n, the halting set HnZ of infinite time n-register machine with oracle Z exists.
27 Jun 2011
TL;DR: It is shown that a single application of the noncomputable operator EC, which transforms enumerations of sets to their characteristic functions, suffices to compute the Radon-Nikodym derivative dµ/dλ of a finite measure µ, which is absolutely continuous w.r.t. the σ-finite measure λ.
Abstract: We show that a single application of the noncomputable operator EC, which transforms enumerations of sets (in N) to their characteristic functions, suffices to compute the Radon-Nikodym derivative dµ/dλ of a finite measure µ, which is absolutely continuous w.r.t. the σ-finite measure λ. We also give a condition on the two measures (in terms of computability of the norm of a certain linear operator involving the two measures) which is sufficient to compute the derivative.
01 Nov 2011
TL;DR: The findings demonstrate that Mimi's visual interface offers musicians the opportunity to anticipate and to review decisions, thus making it an ideal performance and pedagogical tool for improvisation.
Abstract: This article describes the design and implementation of the Multimodal Interactive Musical Improvisation (Mimi) system. Unique to Mimi is its visual interface, which provides the performer with instantaneous and continuous information on the state of the system, in contrast to other human-machine improvisation systems, which require performers to grasp and intuit possible extemporizations in response to machine-generated music without forewarning. In Mimi, the information displayed extends into the near future and reaches back into the recent past, allowing the performer awareness of the musical context so as to plan their response accordingly. This article presents the details of Mimi's system design, the visual interface, and its implementation using the formalism defined by Francois' Software Architecture for Immersipresence (SAI) framework. Mimi is the result of a collaborative iterative design process. We have recorded the design sessions and present here findings from the transcripts that provide evidence for the impact of visual support on improvisation planning and design. The findings demonstrate that Mimi's visual interface offers musicians the opportunity to anticipate and to review decisions, thus making it an ideal performance and pedagogical tool for improvisation. It allows novices to create more contextually relevant improvisations and experts to be more inventive in their extemporizations.
27 Jun 2011
TL;DR: A new optimum-time synchronization algorithm that can synchronize any two-dimensional rectangle arrays of size m×n with a general at one corner in m+n+max(m, n)-3 steps is proposed.
Abstract: The firing squad synchronization problem on cellular automata has been studied extensively for more than fifty years, and a rich variety of synchronization algorithms have been proposed for not only one-dimensional arrays but two-dimensional arrays. In the present paper, we propose a new optimum-time synchronization algorithm that can synchronize any two-dimensional rectangle arrays of size m×n with a general at one corner in m+n+max(m, n)-3 steps. The algorithm is based on a simple recursive halving marking schema which helps synchronization operations on two-dimensional arrays. A proposed computer-assisted implementation of the algorithm gives a description of a two-dimensional cellular automaton in terms of a finite 384-state set and a local 112690- rule set.
14 Nov 2011
TL;DR: The approach makes use of social networks as a mechanism for providing social awareness to individual users of an IPTV system to facilitate an intuitive and simple media selection mechanism when considering vast amounts of live TV channels and on-demand content.
Abstract: Internet Television (IPTV) is emerging as a new delivery method for offering access to digital TV and interactive services which potentially merge the “lean back” broadcast experience with more bidirectional “lean forward” interactivity. Within these environments, there is a significant growth in the volume and variety of content being offered which increases the difficulty and burden for the end-user in locating relevant content and finding something to watch. In this article we detail the design, implementation, and evaluation of a production IPTV service which operates on our University campus network. Our approach makes use of social networks as a mechanism for providing social awareness to individual users of an IPTV system. The goal is to facilitate an intuitive and simple media selection mechanism when considering vast amounts of live TV channels and on-demand content. Ultimately, we seek to explore whether social awareness can or does influence user behavior.
01 Apr 2011
TL;DR: A robust, lightweight, low-profile, and fully restorable display system that can be easily and quickly installed for use in existing public buildings, and considerably reduced the number of physical components and the system weight.
Abstract: The use of large visual displays in public spaces such as large buildings has become increasingly popular. Public art can make use of the characteristics and context of the site. However, it is difficult to install new displays in existing buildings because of the large, rigid hardware associated with such displays. In this article, we describe a robust, lightweight, low-profile, and fully restorable display system that can be easily and quickly installed for use in existing public buildings. We considerably reduced the number of physical components and the system weight with our proposed method, which can be optimized for any planned content. We describe the technical design and implementation of the display system and discuss some of its applications for public audiences. We then report a three-month field trial that we conducted at an airport terminal building. We discuss the advantages and effectiveness of this system in light of the field trial results.
27 Jun 2011
TL;DR: A new model of fe-Systems is presented in which fe-systems define single languages (fe-languages) based on forbidden and enforced subwords, and how an fe- system can generate the solution to the k-colorability problem and model splicing is described.
Abstract: Motivated by biomolecular computing, forbidding-enforcing systems (fe-systems) were first used to define classes of languages (fefamilies) based on boundary conditions. This paper presents a new model of fe-systems in which fe-systems define single languages (fe-languages) based on forbidden and enforced subwords. The paper characterizes well-known languages by fe-systems, investigates the relationship between fefamilies and fe-languages, and describes how an fe-system can generate the solution to the k-colorability problem and model splicing.
01 Jul 2011
TL;DR: An affective audio system for Lovotics which will act as an active participant in a bidirectional nonverbal communication process with humans and offer new possibilities for exploring the concept and possibilities of human-robot love.
Abstract: The aim of the "Lovotics" (Love + Robotics) research is to accomplish an amicable relationship between humans and robots to create a sentimental robotic system that is engaged in a reciprocal affective interaction with humans. This article will outline the part of the project focus which is to develop an affective audio system for Lovotics which will act as an active participant in a bidirectional nonverbal communication process with humans. This interactive audio system is capable of synthesizing real-time audio output based on eight parameters, namely, pitch, number of harmonics, amplitude, tempo, sound envelope, chronemics, proximity, and synchrony. In addition to the first five common parameters, we focused on comprehensive research and user testing on the chronemics, proximity, and synchrony (C.P.S. effect) and aimed to find out how these three factors enhance positive feelings in the human-robot interaction. These factors were determined through our study and were found to have a positive effect on the emotional interaction between humans and robots. Thus, an interactive feedback audio system is implemented which allows sentimental interaction between humans and robots. The aim of such a system is to offer new possibilities for exploring the concept and possibilities of human-robot love.
27 Jun 2011
TL;DR: This work studies computability theoretic properties of computable injection structures and the complexity of isomorphisms between these structures.
Abstract: We study computability theoretic properties of computable injection structures and the complexity of isomorphisms between these structures.
01 Nov 2011
TL;DR: Results show that the Games@Large (GaL) distributed-gaming system has a high potential at Internet cafes, in particular when playing a casual genre game, and provide recommendations for deploying such systems in terms of social setting and technical aspects.
Abstract: Distributed gaming enables access to interactive media from devices based on different platforms. It facilitates users to enjoy video games in various environments without the need for using a single device or operating system. Understanding the potential and limitations of such gaming-on-demand systems is key for their adoption and further growth in public places. This paper presents an in-depth, quantitative study performed with the Games@Large (GaL) distributed-gaming system and its potential users at an Internet cafe in Genoa, Italy. The approach of the study was multilevel, covering the player experience and user acceptance aspects as well as technical performance peculiarities. Results show that the GaL system has a high potential at Internet cafes, in particular when playing a casual genre game. Furthermore, results provide recommendations for deploying such systems in terms of social setting and technical aspects. The methodology and findings of the GaL system tests can be applied to similar game streaming systems and used as input for theories on social digital game play.
27 Jun 2011
TL;DR: For theories T containing a sufficiently rich part of true arithmetic, ConT is characterized as the minimal extension of T proving for some algorithm that it decides Q0 as fast as any algorithm B with the property that T proves that B decisions Q0.
Abstract: Assume that the problem Q0 is not solvable in polynomial time. For theories T containing a sufficiently rich part of true arithmetic we characterize T ∪{ConT} as the minimal extension of T proving for some algorithm that it decides Q0 as fast as any algorithm B with the property that T proves that B decides Q0. Here, ConT claims the consistency of T. Moreover, we characterize problems with an optimal algorithm in terms of arithmetical theories.
27 Jun 2011
TL;DR: The main theorem uses the MRCA model to give a natural characterization of the computability of sets in Euclidean space, provided that their boundaries are computably nowhere dense.
Abstract: This paper introduces multi-resolution cellular automata (MRCA), a multi-resolution variant of cellular automata. Cells in an MRCA are allowed to "fission" one or more times during the course of execution. At any given time, the MRCA may thus be carrying out computations on a variety of spatial scales. Our main theorem uses the MRCA model to give a natural characterization of the computability of sets in Euclidean space, provided that their boundaries are computably nowhere dense.
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TL;DR: A poetry generating system called "Poetry Mix-up" which encourages users to experience the creation of a "remixed" variety of poetry by sending a simple SMS, and shows that Poetrymix-up could be a new form of social and cultural communication in the digital era.
Abstract: Computer technology has become exceedingly integrated with modern culture, which prompted us to introduce and explore the avenues of integrating aesthetics with technology, familiar ground of modern society. With the intention of promoting aesthetic sensibilities generated in poetry, we introduce a poetry generating system called "Poetry Mix-up" which encourages users to experience the creation of a "remixed" variety of poetry by sending a simple SMS. In this system, WordNet-based Word Sense Disambiguating (WSD) and topic summarizing algorithms are implemented to understand the input short messages which will be categorized into several main topics. Based on the topics and the content of the input message, the system creates a new poem by mixing existing poem lines. The preliminary user study shows that Poetry Mix-up could be a new form of social and cultural communication in the digital era.
01 Nov 2011
TL;DR: It seems that the implementation of a personalization and recommendation tool might stimulate the adoption as well as the use diffusion of digital TV in Flanders.
Abstract: Digital television was introduced to the Belgian market in 2005, which is fairly late compared to other European countries. By 2010, in Flanders the 50p penetration threshold of digital television households was surpassed. Considering previous research into the adoption of digital television in Belgium, it can be stated that the “majority segments” have embraced iDTV. However, research suggests that this has not necessarily induced a change in their viewing habits and that interactive applications such as video on demand, time-shifted viewing, voting, email, etc., have remained “underused.” Therefore, the user adoption rate of 50p for iDTV does not automatically imply a 50p use diffusion rate of interactive services. Within the iDTV industry, an important challenge will be to convince the remaining 50p of analog viewers to make the switch to digital television. A review of the literature on the adoption and diffusion processes of technologies shows that these later adopters (laggards and late majority) base their decision on the behavior of peers who have already acquired the technology. As they are the least innovative market segment, they will require some compelling arguments to adopt iDTV. These selling arguments could be related to the added value of interactive services which are currently not being used to their full potential by iDTV subscribers. One of the ideas that is currently explored is personalized television content, recommended to television viewers based on their viewing behavior. This article discusses three important research questions based on quantitative empirical data. Firstly, what is the current state-of-the-art in Flanders regarding the adoption and use diffusion of digital television in Flandersq Secondly, what is the interest in a personalization and recommendation tool for iDTV in Flandersq Thirdly, how would an introduction of this tool affect the adoption and use diffusion of iDTV in Flandersq Based on the results presented in this article, it seems that the implementation of a personalization and recommendation tool might stimulate the adoption as well as the use diffusion of digital TV in Flanders.
27 Jun 2011
TL;DR: This paper proposes a condition for rejecting the input word by an accepting splicing system which is defined by a finite set of forbidding words and shows that the new condition strictly increases the computational power of acceptingSplicing systems.
Abstract: In this paper we propose a condition for rejecting the input word by an accepting splicing system which is defined by a finite set of forbidding words. More precisely, the input word is accepted as soon as a permitting word is obtained provided that no forbidding word has been obtained so far, otherwise it is rejected. Note that in the new variant of accepting splicing system the input word can be rejected if either no permitting word is ever generated (like in [10]) or a forbidding word has been generated and no permitting word had been generated before. We investigate the computational power of the new variants of accepting splicing systems. We show that the new condition strictly increases the computational power of accepting splicing systems. Rather surprisingly, accepting splicing systems considered here can accept non-regular languages, a situation that has never occurred in the case of (extended) finite splicing systems without additional restrictions.
27 Jun 2011
TL;DR: This work investigates structures recognizable by α-automata with running time a limit ordinal α and determines the suprema of the α-automatic ordinals and the ranks of α- automatic linear orders.
Abstract: We investigate structures recognizable by α-automata with running time a limit ordinal α. The domain of such a structure consists of finite α-words with gaps. An α-automaton resembles a finite automaton but has a limit rule which maps the set of states which appear cofinally often before the limit to a limit state. We determine the suprema of the α-automatic ordinals and the ranks of α-automatic linear orders. The power of α-automata increases with every power of ω.