203 research outputs found

    Robust Stackelberg Equilibria in Extensive-Form Games and Extension to Limited Lookahead

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    Stackelberg equilibria have become increasingly important as a solution concept in computational game theory, largely inspired by practical problems such as security settings. In practice, however, there is typically uncertainty regarding the model about the opponent. This paper is, to our knowledge, the first to investigate Stackelberg equilibria under uncertainty in extensive-form games, one of the broadest classes of game. We introduce robust Stackelberg equilibria, where the uncertainty is about the opponent's payoffs, as well as ones where the opponent has limited lookahead and the uncertainty is about the opponent's node evaluation function. We develop a new mixed-integer program for the deterministic limited-lookahead setting. We then extend the program to the robust setting for Stackelberg equilibrium under unlimited and under limited lookahead by the opponent. We show that for the specific case of interval uncertainty about the opponent's payoffs (or about the opponent's node evaluations in the case of limited lookahead), robust Stackelberg equilibria can be computed with a mixed-integer program that is of the same asymptotic size as that for the deterministic setting.Comment: Published at AAAI1

    Metal Organic Materials as Biomimetic Heme Catalysts

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    Stereoselective radical C–H alkylation with acceptor/acceptor-substituted diazo reagents via Co(II)-based metalloradical catalysis

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    Co(II)-based metalloradical catalysis has, for the first time, been successfully applied for asymmetric intramolecular C–H alkylation of acceptor/acceptor-substituted diazo reagents. Through the design and synthesis of a new D2-symmetric chiral amidoporphyrin as the supporting ligand, the Co(II)-based metalloradical system, which operates at room temperature, is capable of 1,5-C–H alkylation of α-methoxycarbonyl-α-diazosulfones with a broad range of electronic properties, providing the 5-membered sulfolane derivatives in high yields with excellent diastereoselectivities and enantioselectivities. In addition to complete chemoselectivity toward allylic and allenic C–H bonds, the Co(II)-based metalloradical catalysis for asymmetric C–H alkylation features a remarkable degree of functional group tolerance

    Pengaruh Sosialisasi Perpajakan, Pengetahuan Perpajakan, dan Kualitas Pelayanan terhadap Kepatuhan Wajib Pajak dengan Kesadaran Wajib Pajak sebagai Variabel Intervening (Studi pada Kantor Pelayanan Pajak Pratama Pekanbaru Senapelan)

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    The purpose of this research are to analyze the influence of taxpayer socialization, taxpayer knowledge, and quality of service to taxpayer compliance, directly or indirectly, by usingtaxpayer awareness as an intervening variable.The sample of this research from of 100 correspondences who are as taxpayers listed in KPP Pratama Pekanbaru Senapelan.The method of sampling using convenience sampling. The data were analysed using the path analysis with SPSS version 19.0. The results of the research showed that the tax socialization did have effect to the tax awareness. Secondly, the tax knowledge did have effect to the tax awareness. Third, quality of service did have effect to the tax awareness.Fourth, the tax socialization did have effect tothe tax compliance. Fifth, the tax knowledge did have effect tothe tax compliance. Sixth, quality of service did have noteffect tothe tax compliance. Seventh, the tax awareness did have effect tothe tax compliance. Eighth, the tax awareness incapable as an intervening variable tax socialization to tax compliance. Ninth, the tax awareness incapable as an intervening variable tax knowledge to tax compliance. Tenth, the tax awareness able as an intervening variable quality of service to tax compliance

    Texture-Governed Cell Response to Severely Deformed Titanium

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    The phenomenon of superior biological behavior , r it observed in titanium processed by an unconventional severe plastic deformation method, that is, hydrostatic extrusion, has been described within the present study. In doing so, specimens varying significantly in the crystallographic orientation of grains, yet exhibiting comparable grain refinement, were meticulously investigated. The aim was to find the clear origin of enhanced biocompatibility of titanium-based materials, having microstructures scaled down to the submicron range. Texture, microstructure, and surface characteristics, that is, wettability, roughness, and chemical composition, were examined as well as protein adsorption tests and cell response studies were carried out. It has been concluded that, irrespective of surface properties and mean grain size, the (10 (1) over bar0) crystallographic plane favors endothelial cell attachment on the surface of the severely deformed titanium. Interestingly, an enhanced albumin, fibronectin, and serum adsorption as well as dearly directional growth of the cells with preferentially oriented cell nuclei have been observed on the surfaces having (0001) planes exposed predominantly. Overall, the biological response of titanium fabricated by severe plastic deformation techniques is derived from the synergistic effect of surface irregularities, being the effect of refined microstructures, surface chemistry, and crystallographic orientation of grains rather than grain refinement itself

    Synthesis and Optical Properties of One Year Air-Stable Chiral Sb(III) Halide Semiconductors

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    Chiral hybrid metal-halide semiconductors (MHS) pose as ideal candidates for spintronic applications owing to their strong spin-orbit coupling (SOC), and long spin relaxation times. Shedding light on the underlying structure-property relationships is of paramount importance for the targeted synthesis of materials with an optimum performance. Herein, we report the synthesis and optical properties of 1D chiral ( -/ -THBTD)SbBr (THBTD = 4,5,6,7-tetrahydro-benzothiazole-2,6-diamine) semiconductors using a multifunctional ligand as a countercation and a structure directing agent. ( -/ -THBTD)SbBr feature direct and indirect band gap characteristics, exhibiting photoluminescence (PL) light emission at RT that is accompanied by a lifetime of a few ns. Circular dichroism (CD), second harmonic generation (SHG), and piezoresponse force microscopy (PFM) studies validate the chiral nature of the synthesized materials. Density functional theory (DFT) calculations revealed a Rashba/Dresselhaus (R/D) spin splitting, supported by an energy splitting ( ) of 23 and 25 meV, and a Rashba parameter (α ) of 0.23 and 0.32 eV·Å for the and analogs, respectively. These values are comparable to those of the 3D and 2D perovskite materials. Notably, ( -THBTD)SbBr has been air-stable for a year, a record performance among chiral lead-free MHS. This work demonstrates that low-dimensional, lead-free, chiral semiconductors with exceptional air stability can be acquired, without compromising spin splitting and manipulation performance

    One-Year Water-Stable and Porous Bi(III) Halide Semiconductor with Broad-Spectrum Antibacterial Performance

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    Hybrid metal halide semiconductors are a unique family of materials with immense potential for numerous applications. For this to materialize, environmental stability and toxicity deficiencies must be simultaneously addressed. We report here a porous, visible light semiconductor, namely, (DHS)Bi2I8 (DHS = [2.2.2] cryptand), which consists of nontoxic, earth-abundant elements, and is water-stable for more than a year. Gas- and vapor-sorption studies revealed that it can selectively and reversibly adsorb H2O and D2O at room temperature (RT) while remaining impervious to N2 and CO2. Solid-state NMR measurements and density functional theory (DFT) calculations verified the incorporation of H2O and D2O in the molecular cages, validating the porous nature. In addition to porosity, the material exhibits broad band-edge light emission centered at 600 nm with a full width at half-maximum (fwhm) of 99 nm, which is maintained after 6 months of immersion in H2O. Moreover, (DHS)Bi2I8 exhibits bacteriocidal action against three Gram-positive and three Gram-negative bacteria, including antibiotic-resistant strains. This performance, coupled with the recorded water stability and porous nature, renders it suitable for a plethora of applications, from solid-state batteries to water purification and disinfection

    Decarboxylative Amination: Diazirines as Single and Double Electrophilic Nitrogen Transfer Reagents

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    The ubiquity of nitrogen-containing small molecules in medicine necessitates the continued search for improved methods for C–N bond formation. Electrophilic amination often requires a disparate toolkit of reagents whose selection depends on the specific structure and functionality of the substrate to be aminated. Further, many of these reagents are challenging to handle, engage in undesired side reactions, and function only within a narrow scope. Here we report the use of diazirines as practical reagents for the decarboxylative amination of simple and complex redox-active esters. The diaziridines thus produced are readily diversifiable to amines, hydrazines, and nitrogen-containing heterocycles in one step. The reaction has also been applied in fluorous phase synthesis with a perfluorinated diazirine.</p

    Practical and Scalable Installation of Neglected S(VI) Functionality with Applications to the Enantiospecific Synthesis of Pharmaceuticals

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    Sulfoximines and related sulfonimidoyl groups have been largely ignored for decades until their value was demonstrated in biological settings. The realization of their importance has ushered in a new wave of discovery and pharmaceutical applications. In attempts to remove the “neglected” description of the lesser-known S(VI) groups, a practical and modular approach for a-substituted heterocycles bearing sulfonimidoyl functional groups was developed. A variety of sulfoximines containing diverse functionality and complexity were rapidly introduced in an enantiospecific fashion with good to excellent yields. Pharmaceutically important heterocyclic scaffolds were shown to undergo the facile nucleophilic substitution, while sulfoximines, sulfonimidamides and sulfondiimines were all demonstrated to be compatible nucleophiles. The utility and practicality of the method was exhibited in target- and diversity-oriented syntheses of four sulfoximine-containing pharmaceuticals including ceralasertib, an ATR inhibitor currently in clinical trials. The introduction of underexplored sulfur functionality to common heterocyclic pharmacophores provides a practical platform for rapid analog development that is expected to aid future efforts in the discovery sciences.</p

    Crystal Structure of Ethyl 4-[(E)-(4-hy-droxy-3-meth-oxy-benzyl-idene)amino]-benzoate: a p-hy-droxy Schiff Base

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    The title p-hy-droxy Schiff base, C17H17NO4, was synthesized via the condensation reaction of benzocaine with vanillin. The benzyl-idine and benzoate rings are inclined to one another by 24.58 (8)°, and the conformation about the C=N bond is E. In the crystal, mol-ecules are linked by O-H⋯N hydrogen bonds, forming zigzag chains propagating along [010]. Adjacent chains are linked by C-H⋯π and weak offset π-π inter-actions [inter-centroid distance = 3.819 (1) Å], forming sheets parallel to (10-2)
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