End Games Research Articles

Fast Payoff Matrix Sparsification Techniques for Structured Extensive-Form Games

The practical scalability of many optimization algorithms for large extensive-form games is often limited by the games' huge payoff matrices. To ameliorate the issue, Zhang and Sandholm recently proposed a sparsification technique that factorizes the payoff matrix A into a sparser object A = Â + UVᵀ, where the total combined number of nonzeros of Â, U, and V, is significantly smaller. Such a factorization can be used in place of the original payoff matrix in many optimization algorithm, such as interior-point and second-order methods, thus increasing the size of games that can be handled. Their technique significantly sparsifies poker (end)games, standard benchmarks used in computational game theory, AI, and more broadly. We show that the existence of extremely sparse factorizations in poker games can be tied to their particular Kronecker-product structure. We clarify how such structure arises and introduce the connection between that structure and sparsification. By leveraging such structure, we give two ways of computing strong sparsifications of poker games (as well as any other game with a similar structure) that are i) orders of magnitude faster to compute, ii) more numerically stable, and iii) produce a dramatically smaller number of nonzeros than the prior technique. Our techniques enable—for the first time—effective computation of high-precision Nash equilibria and strategies subject to constraints on the amount of allowed randomization. Furthermore, they significantly speed up parallel first-order game-solving algorithms; we show state-of-the-art speed on a GPU.

Making and remaking the Galaxy Far, Far Away

This article examines West End Games’ Star Wars: The Roleplaying Game, first published in 1987, and its foundational role in the worldbuilding process of the Star Wars franchise (1977-). In producing the game, West End Games contributed significantly to defining and organizing the storyworld, refining and expanding the scope of Star Wars by integrating some earlier transmedial extensions while excluding others. Coming at an early point in the franchise’s history, before Lucasfilm exerted as much control over its licensees, The Roleplaying Game offers an opportunity to examine the role that licensed game designers can play as architects and gatekeepers of transmedia worldbuilding, codifying what is and is not remembered within the storyworld. The Roleplaying Game has often been reduced to a footnote in both the popular and academic history of Star Wars transmedia, but beyond adapting the Galaxy Far, Far Away to a setting for imaginative tabletop roleplaying, The Roleplaying Game is also a foundational document for the last three decades of the Star Wars franchise, serving as the early ‘story bible’ for the Expanded Universe, the intercon­nected network of Star Wars paratexts codified by the licensing department of Lucasfilm during the 1990s. The hundreds of Star Wars novels, comics, games and other transmedia productions that came with the franchise’s dramatic rebirth in the 1990s bear the stamp of the worldbuilding labour of West End Games.

Investigation and Analysis on Game Players’ Preferences—Take Xi’an as an Example

This investigation was conducted by means of personal contact. The interviewees were selected from universities and Internet cafes in Xi'an. In addition to the investigation of crowd characteristics of game players, there are two aspects involved in the investigation of preferences. One is the investigation of game style preferences. and the other is a survey of the habits and preferences of game players. The survey of game style preference includes the preference of drawing style, the preference of overall style, the preference basis of game characteristics and the influencing factors of game experience. According to the analysis of survey data, game players like Chinese style games with good visual perception, strong sense of substitution and easy to use in terms of style preference. In terms of the investigation on the habits of game players, according to the analysis of the investigation data, it is more likely to attract the players when the game starts to design charging items about half an hour; in addition to strengthening the competitiveness in terms of the game content and plot, it is also necessary to strengthen the competitive situation setting in the lower stage of the game, strengthen the sense of bringing in, and design equipment or other items with low price The key point of the design is to attract the players to go deep; the plot design of the game after half an hour and the longer time to attract the players are very important. In 2018, China's game market revenue reached 203.61 billion yuan, with mobile games accounting for 57%. The revenue of mobile games exceeded 100 billion yuan, while the revenue of end games continued to grow, with an increase of 11.4%. The revenue of page games is only 15.6 billion, showing negative growth for two consecutive years. The market revenue of e-games exceeds 70 billion, and the revenue of mobile e-games grows rapidly. IP game revenue reached 74.56 billion, accounting for 64.2% of mobile game revenue. The revenue of plane games reached 15.98 billion with an increase of 45%. In order to know which games will be more attractive to the game players and which embedded consumption items will be more attractive to the game players, a preference survey is carried out for the game players in order to understand the consumption characteristics of the main consumer groups of the game and provide reference for the majority of game companies to make games and design charging items.

Review

Review

Secular studies come of age

In this essay I review three important volumes for the field of secular studies: Varieties of Secularism in a Secular Age, Rethinking Secularism, and The Power of Religion in the Public Sphere. All three volumes explore the nature of the secular and the status, role, and possible futures of religion in our late modern, globalized world. The volumes present 34 essays by 30 authors representing seven disciplines, and at least six end games. For some, questions of religion-secular entanglement are a historical matter and the task is to map intellectual and ideological trajectories. A second purpose is to empirically document the complexities of particular religion-secular entanglements in particular socio-cultural locations. For others, the remit is theoretical, to discern a conceptual agenda for the ongoing study of religion-secular entanglements. Others are more philosophical, chasing the existential consequences of secularity. A fifth end game is applied in nature: reflections on how political actors might best engage the religious and the secular in acts of governance and international relations. Finally, there are normative voices, those seeking to name what a good, productive religion-secular entanglement ought to look like. Taken together, the volumes mark a thriving, mature field of scholarly inquiry: secular studies has come of age.

Proceedings of the 2nd People that Deliver (2nd PtD) Global Conference on Human Resources in Supply Chain Management.

Background While much attention is on relatively near-term goals (eg Family Planning (FP) 2020), there is growing interest in and a need to address longer term, in-a-generation “end games” (e.g., to 2035), as well as post-2015 Millennium Development Goals (MDGs). The health supply systems of today need to prepare themselves to take advantage of future trends and opportunities. The next generation will see a number of changes (known and unknown) that will both challenge the ability of public health supply systems to function effectively as they are currently designed and create opportunities for increased efficiency.

End Games. Notes about Hejduk's architecture

L’autore si interroga sul “senso complessivo” del lavoro di uno dei più importanti architetti della seconda metà del '900, tentando una lettura unitaria delle diverse fasi di cui si compone la sua opera: una prima fase tutta centrata sulla rivisitazione e lo sviluppo di canoni linguistici modernisti; una seconda di stampo “urbanistico”; quella successiva, della prima metà degli anni '90 più poetica, autenticamente creativa e immaginifica fino all'ultima tutta intrisa di religiosa spiritualità.

Beginning and End Games

Beginning and End Games

On Constructing Static Evaluation Function using Temporal Difference Learning

Programming computers to play board games against human players has long been used as a measure for the development of artificial intelligence. The standard approach for computer game playing is to search for the best move from a given game state by using minimax search with static evaluation function. The static evaluation function is critical to the game playing performance but its design often relies on human expert players. This paper discusses how temporal differences (TD) learning can be used to construct a static evaluation function through self-playing and evaluates the effects for various parameter settings. The game of Kalah, a non-chance game of moderate complexity, is chosen as a testbed. The empirical result shows that TD learning is particularly promising for constructing a good evaluation function for the end games and can substantially improve the overall game playing performance in learning the entire game.DOI:Â 10.18495/comengapp.21.175184

Evolved to Win (Sipper, M.; 2011) [Book Review

This book contains 12 chapters, of which 8 are descriptions of how the author used genetic programming to solve different games. In order, the games Prof. Sipper describes are lose checkers, chess end games, search algorithms for regular chess, backgammon, simulated Robocode,simulated racing cars, the puzzle Rush Hour, and the puzzle FreeCell. Each chapter, and one additional detailed chapter for lose checkers, gives a comprehensive description on how the author solved the game using genetic programming. The reader can get a good understanding of the work and approach used to solve the game before delving deeper into the original conference and journal papers published by the author for more rigorous descriptions and empirical results.

What comes next after recession? – Airline industry scenarios and potential end games

While airline managers learned lessons from the 2001/2003 “double dip” economic crisis, the post 2008 downturn has been more extreme. Airlines reacted quickly in 2008 and adjusted capacities and cost levels but recovery in profits has been slow for many airlines. The dynamics of the downturn has enlarged the gap between successful and less successful business models, and fostered shakeouts of the latter. Furthermore, the occurrence of new business models has accelerated. In 2001, it was the European continental low cost model; this time, we may see new attempts to change the rules of the game in international long-haul traffic. Long-term non-cyclical trends such as deregulation or consolidation will also shape potential end game scenarios, We briefly examine the differences between the last (2001/03) and the recent (2008/09) aviation crises, and evaluate the impact on different types of carriers.

Strategic insights from playing quantum tic-tac-toe

In this paper, we perform a minimalistic quantization of the classical game of tic-tac-toe, by allowing superpositions of classical moves. In order for the quantum game to reduce properly to the classical game, we require legal quantum moves to be orthogonal to all previous moves. We also admit interference effects, by squaring the sum of amplitudes over all moves by a player to compute his or her occupation level of a given site. A player wins when the sum of occupations along any of the eight straight lines we can draw in the 3 × 3 grid is greater than or equal to 3. We play the quantum tic-tac-toe first randomly, and then deterministically, to explore the impact different opening moves, end games and different combinations of offensive and defensive strategies have on the outcome of the game. In contrast to the classical tic-tac-toe, the deterministic quantum game does not always end in a draw. In contrast also to most classical two-player games of no chance, it is possible for player 2 to win. More interestingly, we find that player 1 enjoys an overwhelming quantum advantage when he opens with a quantum move, but loses this advantage when he opens with a classical move. We also find the quantum blocking move, which consists of a weighted superposition of moves that the opponent could use to win the game, to be very effective in denying the opponent his or her victory. We then speculate what implications these results might have on quantum information transfer and portfolio optimization.

Total Syntheses of Amphidinolide X and Y

Concise total syntheses of the cytotoxic marine natural products amphidinolide X (1) and amphidinolide Y (2) as well as of the nonnatural analogue 19-epi-amphidinolide X (47) are described. A pivotal step of the highly convergent routes to these structurally rather unusual secondary metabolites consists of a syn-selective formation of allenol 17 by an iron-catalyzed ring opening reaction of the enantioenriched propargyl epoxide 16 (derived from a Sharpless epoxidation) with a Grignard reagent. Allenol 17 was then cyclized with the aid of Ag(I) to give dihydrofuran 19 containing the (R)-configured tetrasubstituted sp3 chiral center at C.19, which was further elaborated into tetrahydrofuran 25 representing the common heterocyclic motif of 1 and 2. The aliphatic chain of amphidinolide X featuring an anti-configured stereodiad at C.10 and C.11 was generated by a palladium-catalyzed, Et2Zn-promoted addition of the enantiopure propargyl mesylate 29 to the functionalized aldehyde 28. The preparation of the corresponding C.1-C.12 segment of amphidinolide Y relies on asymmetric hydrogenation of an alpha-ketoester, a diastereoselective boron aldol reaction, and a chelate-controlled addition of MeMgBr in combination with suitable oxidation state management for the elaboration of the tertiary acyloin motif. Importantly, the end games of both total syntheses follow similar blueprints, involving key fragment coupling processes via the "9-MeO-9-BBN" variant of the alkyl-Suzuki reaction and final Yamaguchi esterifications to forge the 16-membered macrodiolide ring of amphidinolide X and the 17-membered macrolide frame of amphidinolide Y, respectively. This methodological convergence ensures high efficiency and an excellent overall economy of steps for the entire synthesis campaign.

Growth Factor Withdrawal and Apoptosis: The Middle Game

In this issue of Molecular Cell, detail molecular events that trigger apoptosis following growth factor withdrawal, linking irreversible mitochondrial permeabilization to activation of GSK-3 and subsequent phosphorylation, ubiquitinylation, and degradation of the antiapoptotic BCL-2 family member MCL-1.

Postconditioning A new link in nature’s armor against myocardial ischemia–reperfusion injury

Reperfusion injury is a complex process involving several cell types (endothelial cells, neutrophils, and cardiomyocytes), soluble proinflammatory mediators, oxidants, ionic and metabolic dyshomeostasis, and cellular and molecular signals. These participants in the pathobiology of reperfusion injury are not mutually exclusive. Some of these events take place during the very early moments of reperfusion, while others, seemingly triggered in part by the early events, are activated within a later timeframe. Postconditioning is a series of brief mechanical interruptions of reperfusion following a specific prescribed algorithm applied at the very onset of reperfusion. This algorithm lasts only from 1 to 3 minutes depending on species. Although associated with re-occlusion of the coronary artery or re-imposition of hypoxia in cell culture, the reference to ischemia has been dropped. Postconditioning has been observed to reduce infarct size and apoptosis as the "end games" in myocardial therapeutics; salvage of infarct size was similar to that achieved by the gold standard of protection, ischemic preconditioning. The cardioprotection was also associated with a reduction in: endothelial cell activation and dysfunction, tissue superoxide anion generation, neutrophil activation and accumulation in reperfused myocardium, microvascular injury, tissue edema, intracellular and mitochondrial calcium accumulation. Postconditioning sets in motion triggers and signals that are functionally related to reduced cell death. Adenosine has been implicated in the cardioprotection of postconditioning, as has e-NOS, nitric oxide and guanylyl cyclase, opening of K(ATP) channels and closing of the mitochondrial permeability transition pore. Cardioprotection by postconditioning has also been associated with the activation of intracellular survival pathways such as ERK1/2 and PI3 kinase - Akt pathways. Other pathways have yet to be identified. Although many of the pathways involved in postconditioning have also been identified in ischemic preconditioning, some may not be involved in preconditioning (ERK1/2). The timing of action of these pathways and other mediators of protection in postconditioning differs from that of preconditioning. In contrast to preconditioning, which requires a foreknowledge of the ischemic event, postconditioning can be applied at the onset of reperfusion at the point of clinical service, i.e. angioplasty, cardiac surgery, transplantation.

Constructing the Olympic Dream: A Future Perfect Strategy of Project Management

In this paper we investigate a uniquely complex organizational context—that of the fast-tracked large-scale project management of a significant piece of Sydney 2000 Olympic infrastructure, which we researched in terms of its management through the “future perfect.” In a grounded analysis we resolved to track how the future perfect developed in the life of one large, complex project whose uniqueness meant that it was unable to be strategically planned in advance. We tracked the use of what we term “future perfect strategy” through analysis of data collected both in leadership meetings of the directing agency, “PALT”—Project Alliance Leadership Team—as well as in individual interviews that we conducted in and around the project, and through analysis of media coverage. Overall, the project was a success, but some problems arose along the way to completion. Largely, these were focused on issues of social rather than technical construction—something even the most strategic of plans cannot account for. As well as identifying some of the specific mechanisms for encouraging future perfect strategy that were used in the project, including encouraging “strange conversations,” “playing end games,” “workshopping,” and “projecting feelings, concerns and issues,” we also suggest some ways that the social construction issues might be handled in the future.

Missile guidance laws based on pursuit–evasion game formulations

The increasing maneuverability potential of tactical ballistic missiles motivates the development of improved interceptor guidance laws. In this paper two guidance laws are compared, both based on a pursuit–evasion differential game formulation. The first game is a linear-quadratic one. The second one is formulated with bounded controls and the miss distance as the performance index. The comparison shows that for the same values of physical parameters the capture zone (guaranteeing zero miss distance) of the guidance law using bounded controls, as well as the control effort associated with it, are larger. However, for short duration end games and for large values of interceptor maneuverability advantage the capture zones nearly coincide.

Missile Guidance Laws Based on Pursuit-Evasion Game Formulations

Two guidance laws are compared, both based on a pursuit-evasion differential game formulation. The first game is a linear-quadratic one. The second one is formulated with bounded controls and the miss distance as the performance index. The comparison shows that for the same values of physical parameters the capture zone of the guidance law using bounded controls is larger. However, for short duration end games and for large interceptor maneuverability advantage the capture zones nearly coincide.

Islands of Conscious Power: Law, Norms, and the Self-Governing Corporation

This article provides a theory of the relation between legal and non legally enforceable rules and in the corporation, and then uses that theory to analyze a variety of prominent features of corporate law. In the first part, we draw on recent developments in the theory of the firm to identify key problems facing participants in the firm. In developing this approach, we combine the property strand in the theory of the firm with the transaction cost approach. From this perspective, the main issue is solving the related problems of coordinating activities, choosing the firm's assets, and developing appropriate incentives for specific investments. In part II, we argue that the firm so understood will largely be governed through norms, by which we mean non-legally enforceable rules and standards (NLERS). Indeed, the raison d'etre of firms is to replace legal/contractual governance of relations with NLERS. Using this framework, in part III, we analyze the duty of loyalty. In part IV, we analyze the duty of care and the business judgement rule, and a variety of other puzzling features of corporate law. From our perspective, corporate law can be understood as a remarkably sophisticated mechanism for facilitating governance by NLERS. Centralized management is used to determine the assets over which the corporation must have residual rights of control and to develop a governance structure for protecting the match-investments of insiders in these assets. Legal rules provide the default settings through which centralized management operate and prohibit non pro rata distributions (a combination of ex ante rules and the ex post duty of loyalty), which pushes controlling shareholders to maximize the value of the firm. Having established an incentive compatible legal form that facilitates NLERS governance, the law must be careful not to undermine that governance by midstream interference. Here, the duty of care and the business judgment rule are critical. The business judgement rule acts as a jurisdictional rule that facilitates a self governing NLERS relationship by preventing parties from turning to third party adjudicators. As such, it plays a role very similar to the role of the employment at will doctrine in employment law and for the same reasons. This analysis provides an explanation for why the duty of care, despite its appearance, does not function as a negligence rule, and why liability for directorial malpractice is so much less common than liability for other forms of professional malpractice, such as, legal or medical. The principal contexts in which the BJR does not apply are situations in which NLERS governance breaks down, generally because of last period temptations to defect. The difference in the ability of NLERS to govern midstream and end games provides the key to understanding a variety of corporate law puzzles. These puzzles include: the asymmetry between the legal governing purchases and sales of assets; the asymmetry between judicial review over decisions to resist all bids for control (just say no) versus the review of sales of control; and the demand requirement in derivative litigation.

Islands of Conscious Power: Law, Norms and the Self Governing Corporation

This article provides a theory of the relation between legal and non legally enforceable rules and in the corporation, and then uses that theory to analyze a variety of prominent features of corporate law. In the first part, we draw on recent developments in the theory of the firm to identify key problems facing participants in the firm. In developing this approach, we combine the property strand in the theory of the firm with the transaction cost approach. From this perspective, the main issue is solving the related problems of coordinating activities, choosing the firm's assets, and developing appropriate incentives for specific investments. In part II, we argue that the firm so understood will largely be governed through norms, by which we mean non-legally enforceable rules and standards (NLERS). Indeed, the raison d'etre of firms is to replace legal/contractual governance of relations with NLERS. Using this framework, in part III, we analyze the duty of loyalty. In part IV, we analyze the duty of care and the business judgement rule, and a variety of other puzzling features of corporate law. From our perspective, corporate law can be understood as a remarkably sophisticated mechanism for facilitating governance by NLERS. Centralized management is used to determine the assets over which the corporation must have residual rights of control and to develop a governance structure for protecting the match-investments of insiders in these assets. Legal rules provide the default settings through which centralized management operate and prohibit non pro rata distributions (a combination of ex ante rules and the ex post duty of loyalty), which pushes controlling shareholders to maximize the value of the firm. Having established an incentive compatible legal form that facilitates NLERS governance, the law must be careful not to undermine that governance by midstream interference. Here, the duty of care and the business judgment rule are critical. The business judgement rule acts as a jurisdictional rule that facilitates a self governing NLERS relationship by preventing parties from turning to third party adjudicators. As such, it plays a role very similar to the role of the employment at will doctrine in employment law and for the same reasons. This analysis provides an explanation for why the duty of care, despite its appearance, does not function as a negligence rule, and why liability for directorial malpractice is so much less common than liability for other forms of professional malpractice, such as, legal or medical. The principal contexts in which the BJR does not apply are situations in which NLERS governance breaks down, generally because of last period temptations to defect. The difference in the ability of NLERS to govern midstream and end games provides the key to understanding a variety of corporate law puzzles. These puzzles include: the asymmetry between the legal governing purchases and sales of assets; the asymmetry between judicial review over decisions to resist all bids for control (just say no) versus the review of sales of control; and the demand requirement in derivative litigation.