cssi/SciSciGPT-SciSciNet huggingface dataset:
The Chandra Deep Survey of the Hubble Deep Field North Area. IV. An Ultradeep Image of the HDF-N

We present results from a 479.7 ks Chandra exposure of the Hubble Deep Field North (HDF-N) and its immediate vicinity. In this X-ray image, the deepest ever reported with a 0.5¨2.0 keV —ux limit of B4.9 ] 10~17 ergs cm~2 s~1, four new HDF-N X-ray sources are detected, bringing the total number of such sources to 12. The new sources include two optically bright (R \ 18.3¨18.8) low-redshift (z \ 0.15) galaxies, a FanaroU-Riley I radio galaxy, and an edge-on spiral galaxy hosting either a powerful starburst and/or a low-luminosity active galactic nucleus (AGN). Notably, X-ray emission has now been detected from all luminous galaxies with z \ 0.15 known in the HDF-N. We have also (M V \ [18) detected the remarkable microjansky radio source VLA J123642.09]621331.4, which is located just outside the HDF-N and has a likely redshift of z \ 4.424. The observed X-ray emission supports the
The rank and minimal border strip decompositions of a skew partition

The rank of an ordinary partition of a nonnegative integer n is the length of the main diagonal of its Ferrers or Young diagram. Nazarov and Tarasov gave a generalization of this definition for skew partitions and proved some basic properties. We show the close connection between the rank of a skew partition λ/µ and the minimal number of border strips whose union is λ/µ. A general theory of minimal border strip decompositions is developed and an application is given to the evaluation of certain values of irreducible characters of the symmetric group.
State health insurance market reforms and access to insurance for high-risk employees.

A specific focus for state regulations of the small group insurance market was to increase offers and stabilize premiums for firms with high-risk workers. We examine the effect of reforms implemented from 1993 through 1996 on the likelihood of employer sponsored insurance coverage. We find that packages of reforms that included both guaranteed issue of some products and some form of rate variance restriction had significant positive effects on ESI coverage for high-risk compared with low-risk workers within small firms and a small negative effect on low-risk workers in small compared with large firms. (Davidoff, Amy, Blumberg, Linda and Nichols, Len. 2005. State Health Insurance Market Reforms and Access to Insurance for High-Risk Employees. Journal of Health Economics 24(4): 725-750.)
On the Enumerability of the Determinant and the Rank

We investigate the complexity of enumerative approximation of two elementary problems in linear algebra, computing the rank and the determinant of a matrix. In particular, we show that if there exists an enumerator that, given a matrix, outputs a list of constantly many numbers, one of which is guaranteed to be the rank of the matrix, then it can be determined in AC0 (with oracle access to the enumerator) which of these numbers is the rank. Thus, for example, if the enumerator is an FL function, then the problem of computing the rank is in FL. The result holds for matrices over any commutative ring whose size grows at most polynomially with the size of the matrix. The existence of such an enumerator also implies a slightly stronger collapse of the exact counting logspace hierarchy. For the determinant function we establish the following two results: (1) If the determinant is poly-enumerable in logspace, then it can be computed exactly in FL. (2) For any prime p, if computing the determinant modulo p is (p-1)-enumerable in FL, then computing the determinant modulo p can be done in FL. This gives a new perspective on the approximability of many elementary linear algebra problems equivalent to computing the rank or the determinant.
Unbiased Cultural Transmission in Time-Averaged Archaeological Assemblages

Neutral models are foundational in the archaeological study of cultural transmission. Applications have assumed that archaeological data represent synchronic samples, despite the accretional nature of the archaeological record. Using numerical simulations, I document the circumstances under which time-averaging alters the distribution of model predictions. Richness is inflated in long-duration assemblages, and evenness is “flattened” compared to unaveraged samples. Tests of neutrality, employed to di erentiate between biased and unbiased models, su er serious problems with Type I error under time-averaging. Estimation of populationlevel innovation rates, which feature in many archaeological applications, are biased even without time averaging, but have sharply increased bias given longer assemblage durations. Finally, the time scale over which time averaging alters predictions is determined by the mean trait lifetime, providing a way to evaluate the impact of these e ects upon archaeological samples.
Laboratory simulations of controlled energetic electron-beam-plasma interactions in space

Abstract : Recent laboratory investigations of space simulated electron beam plasma interactions have concentrated on the transition from single particle behavior to collective plasma processes with emphasis on the beam plasma discharge. The plasma has been characterized with respect to its spatial distributions in density, temperature and density fluctuation power spectra. The latter results have been further classified in terms of amplitude and spectral distributions. The overall results include: (i) detailed radial profiles of plasma density as a function of beam parameters; (ii) the association of low frequency large amplitude fluctuations with ion acoustic, ion cyclotron and drift wave modes; (iii) the identification and spatial mapping of suprathermal electrons in the beam core; and (iv) the experimental definition of a density dependent criterion for the ignition of the beam plasma discharge. The data provide a synoptic perspective on accumulated rocket observations and meaningfully contribute to planning activities for future space borne applications of artificially injected energetic electron beams.
Simple, rapid procedure for the synthesis of chloromethyl methyl ether and other chloro alkyl ethers.

Zinc(II) salts catalyze the reaction between acetals and acid halides to provide haloalkyl ethers in near-quantitative yield. Reactions from millimole to mole scale are typically complete in 1−4 h with 0.01 mol % catalyst. The solutions of haloalkyl ethers thus obtained can be utilized directly in reactions in which the presence of the ester byproduct does not interfere. Excess haloalkyl ether is destroyed on workup, thereby minimizing exposure to this class of carcinogenic compounds.
Product quality, advertising intensity and market size

We develop a model of product differentiation in which firms strategically compete in product quality and advertising intensity. Products exhibit a combination of vertical and horizontal differentiation. A consumer’s utility has a stochastic relationship with quality, but they are more likely to prefer a higher quality good. Consumers face a trade-off between higher quality goods and price. Increased competition leads to less advertising, but may result in higher or lower quality products offered in the market.
Experiments on rigid body-based controllers with input preshaping for a two-link flexible manipulator

Dynamics of multi-link flexible manipulators are highly nonlinear. Furthermore, the vibrational frequencies of these manipulators are configuration-dependent. Therefore, any feedforward or feedback algorithm has to deal with these frequency variations. In this paper, an inner-loop nonlinear controller based on feedback linearization of O(1) dynamics derived from an asymptotic expansion is utilized. It is shown that this control scheme significantly reduces the frequency variations due to the geometric configuration of the arm and cancels some of the nonlinearities due to Coriolis and centripetal effects. The advocated control law is compared and contrasted to an independent joint-based PD controller. However, since the aforementioned controllers are joint-based control schemes, significant vibrations are still induced at the end-effector. To this end, these control schemes are augmented with an input preshaper for vibration suppression. The objective is to preshape the reference input signals so that a vibration free output is achieved. The input preshaping scheme is shown to be effective when the plant dynamics are linear and time-invariant. These assumptions do not hold for the multi-link flexible manipulators as alluded to above. Application of an inner-loop nonlinear control to cancel some of the nonlinearities and to reduce configuration dependence of structural frequencies enhances the performance of the advocated input preshaping scheme or any other outer-loop linear control design. Experimental and simulation results for a two-link flexible manipulator are provided to validate the effectiveness of the advocated controllers. >
Water and Health - are we Concerned Enough?

From a historical point of view, man's concern about the health and protection of water supply is the history of the dramatic reduction in acute communicable diseases due to water-borne micro-organisms. Now that these have been essentially eliminated, there has been a great reduction in concern by scientists and the medical profession with the health aspects of contaminated water. This, in spite of the fact that many concerned people and national advisory groups have reminded us that an increasing number of possible chemical and other hazards find their way into our water supplies and expose human populations to contaminants at low concentration levels without reliable knowledge as to their health effects. Too little research is being done on the health effects of chemicals, pesticides, and viruses. The fact that large populations are being exposed to these possible hazards raises legal and public policy questions. Persons who are largely ignorant of the possible harm of these substances are being exposed to them without consent. Often low level exposure to environmental contaminants is not known or not discovered until considerable time has passed. This raises the question concerning the burden which should be imposed on industry and others who introduce new substances in the environment. The best approach in solving this problem is to prohibit the new substance from being introduced into the environment until it has been shown by reliable studies that even low level exposure is not likely to harm human health.
Modeling and characterization of erbium:ytterbium glass waveguide lasers

Summary form only given. Erbium-ytterbium (Er/sup 3+/-Yb/sup 3+/) codoped glass is an attractive system for short, efficient lasers and amplifiers operating in the long-haul telecommunications range. The pump absorption near 980 nm is increased, and efficient energy transfer between the Yb/sup 3+/ and Er/sup 3+/ ions enables the operation of compact laser devices with low erbium concentrations. We present simple methods that can be used to model the Er/sup 3+/-Yb/sup 3+/ codoped glass system and predict laser performance. Experimental results for fabricated waveguide laser devices are discussed.
Computer assisted instruction in the diagnosis of cardiac arrhythmias

Disorders of heart rhythm, known as cardiac arrhythmias, are most accurately diagnosed from selected electrocardiographic (EKG) tracings. Their interpretation is necessary for the correct treatment, sometimes on an emergency basis, of a large number of patients with heart disease. Analysis of the contour and sequencing of component waveforms taken with the knowledge of the set of denned electrophysiologic mechanisms allows categorization and in most instances specific identification of the rhythm. Most of these diagnoses depend upon the specification of the site or sites of electrical impulse generation in the heart and its subsequent spread through specialized conduction pathways. The logical process leading to the diagnosis is inferential because the tissues involved in impulse generation and specialized conduction are of such small mass as to have no direct electrical representation on standard EKG leads. Only the electrical activation of larger masses of cardiac tissue as a resultant of those fundamental mechanistic events produces the component waveforms of the clinical electrocardiogram.
Indigenous ethnicity and entrepreneurial success in Africa : some evidence from Ethiopia

Researchers have recently been asking why Asian and European minorities in Africa seem to be more successful in business than are people of indigenous ethnicity. The author draws attention to the significant disparity in business ownership and performance that seems to exist among African ethnic groups as well. After analyzing a random selection of small to medium-size manufacturers in Ethiopia, he finds that establishments owned by an indigenous minority ethnic group, the Gurage, typically perform better than those owned by other (major or minority) groups. Other things being equal, Gurage-owned businesses are normally large, partly because they are bigger as start-ups and partly because they grow faster. And yet Gurage business owners are the least educated ethnic group in the sample. Because the size and growth rate of a business also increases with the entrepreneur's education, the performance of other businesses would have been even worse if their owners hadn't been better educated than the Gurage. Indeed, dropping education variables from the size determination equation drastically reduces the estimated advantage of Gurage-run businesses. This suggests that the observed effect of ethnicity could be indicative of intergroup differences in unmeasured ability. More important, it means that whether or not the effect will persist in the long run will depend on the trend in interethnic differences in investment in education.
Sharing computer network logs for security and privacy: a motivation for new methodologies of anonymization

Logs are one of the most fundamental resources to any security professional. It is widely recognized by the government and industry that it is both beneficial and desirable to share logs for the purpose of security research. However, the sharing is not happening or not to the degree or magnitude that is desired. Organizations are reluctant to share logs because of the risk from exposing sensitive information to potential attackers. In this paper we survey current attempts at sharing logs and current log anonymization tools. We further define the problem and describe a roadmap to solve the issues that have to date inhibited large scale log sharing.
Visible light photocatalysis of [2+2] styrene cycloadditions by energy transfer.

Hip to be square: Styrenes participate in [2+2] cycloadditions upon irradiation with visible light in the presence of an iridium(III) polypyridyl complex. In contrast to previous reports of visible light photoredox catalysis, the mechanism of this process involves photosensitization by energy transfer and not electron transfer.
Fractional power control for decentralized wireless networks

We consider a new approach to power control in decentralized wireless networks, termed fractional power control (FPC). Transmission power is chosen as the current channel quality raised to an exponent -s, where s is a constant between 0 and 1. The choices s = 1 and s = 0 correspond to the familiar cases of channel inversion and constant power transmission, respectively. Choosing s isin (0,1) allows all intermediate policies between these two extremes to be evaluated, and we see that usually neither extreme is ideal. We derive closed-form approximations for the outage probability relative to a target SINR in a decentralized (ad hoc or unlicensed) network as well as for the resulting transmission capacity, which is the number of users/m2 that can achieve this SINR on average. Using these approximations, which are quite accurate over typical system parameter values, we prove that using an exponent of s* = 1/2 minimizes the outage probability, meaning that the inverse square root of the channel strength is a sensible transmit power scaling for networks with a relatively low density of interferers. We also show numerically that this choice of s is robust to a wide range of variations in the network parameters. Intuitively, s* = 1/2 balances between helping disadvantaged users while making sure they do not flood the network with interference.
Sequenced Reactions with Samarium(II) Iodide. Sequential Nucleophilic Acyl Substitution/Ketyl Olefin Coupling Reactions for the Preparation of Oxygen Heterocycles

Samarium(II) iodide has been employed to promote a sequential intramolecular nucleophilic acyl substitution/intramolecular ketyl olefin coupling cyclization sequence to provide bicyclic, tricyclic, and spiro-fused oxygen heterocycles in excellent yield and with high diastereoselectivity.
Resynthesis and peephole transformations for the optimization of large-scale asynchronous systems

Several approaches have been proposed for the syntax-directed compilation of asynchronous circuits from high-level specification languages, such as Balsa and Tangram. Both compilers have been successfully used in large real-world applications; however, in practice, these methods suffer from significant performance overheads due to their reliance on straightforward syntax-directed translation.This paper introduces a powerful new set of transformations, and an extended channel-based language to support them, which can be used an optimizing back-end for Balsa. The transforms described in this paper fall into two categories: resynthesis and peephole. The proposed optimization techniques have been fully integrated into a comprehensive asynchronous CAD package, Balsa. Experimental results on several substantial design examples indicate significant performance improvements. supported by NSF ITR Award No. NSF-CCR-0086036 and NSF Award No. CCR-99-88241, and by a grant from the New York State Microelectronics Design Center.
Spherical self-similar solutions in Einstein-multi-scalar gravity

Abstract We consider a general nonlinear sigma model coupled to Einstein gravity and show that in spherical symmetry and for a simple realization of self-similarity, the spacetime can be completely determined. We also examine some more specific matter models and discuss their relation to critical collapse.
Three-dimensional imaging utilizing energy discrimination. II.

A new algorithm for three-dimensional image reconstruction in nuclear medicine in which scattered radiation rather than multiple projected images is used for determination of the source depth within the body is proposed. Images taken from numerous energy windows are combined for the reconstruction of the source distribution in the body. In the first paper of this series Gunter et al. [ IEEE Trans. Nucl. Sci.37, 1300 ( 1990)] examined simple linear algorithms for recovering source depth information from scattered radiation. These linear algorithms were unsuccessful because the scattering process produces little signal in the low-energy images at high spatial frequencies. As a result, the reconstructed source distributions exhibited nodal patterns and blurring. The scattering kernel that was measured and reported in the first paper is now examined more carefully. The singular-value decomposition of the kernel matrices is used to break the reconstruction problem into distinct channels that relate energy spectra to source depth distributions. Based on this analysis, a new nonlinear reconstruction algorithm that avoids the earlier problems is proposed. The new algorithm does not degrade spatial resolution in the imaging plane and provides depth resolution with a standard deviation of 4 cm for point sources without requiring any camera motion. The algorithm also provides significant attenuation correction and, therefore, improved quantitation of the source distribution.
Coresets, sparse greedy approximation, and the Frank-Wolfe algorithm

The problem of maximizing a concave function f(x) in the unit simplex Δ can be solved approximately by a simple greedy algorithm. For given k, the algorithm can find a point x(k) on a k-dimensional face of Δ, such that f(x(k) ≥ f(xa) − O(1/k). Here f(xa) is the maximum value of f in Δ, and the constant factor depends on f. This algorithm and analysis were known before, and related to problems of statistics and machine learning, such as boosting, regression, and density mixture estimation. In other work, coming from computational geometry, the existence of ϵ-coresets was shown for the minimum enclosing ball problem by means of a simple greedy algorithm. Similar greedy algorithms, which are special cases of the Frank-Wolfe algorithm, were described for other enclosure problems. Here these results are tied together, stronger convergence results are reviewed, and several coreset bounds are generalized or strengthened.
Searching for clues to premature aging.

Hutchinson-Gilford Progeria syndrome is a rare developmental disorder affecting most of the organ systems in a manner that mimics natural aging but at a markedly accelerated rate. A recent workshop at the NIH, aimed at further understanding the aging process, took an in-depth look at this complex syndrome.
The Intrinsic Value of Obeying a Law: Economic Analysis of the Internal Viewpoint

Economic theory distinguishes sharply between what a person wants and what he can have. “Preferences” describe what a person wants, and “constraints” describe the limits of what he can have. The collision of preferences and constraints yields the choices that economists study. The meaning of both terms is broad and flexible. Preferences and constraints help to distinguish between the internal and external viewpoints that H. L. A. Hart made famous. The internal viewpoint concerns preferences to perform legal obligations. A person who prefers to obey a law is willing to give up something to perform his legal obligation. The preference is intrinsic, not an instrument for securing something else of value. Conversely, a person who is indifferent to a legal obligation takes a purely instrumental approach towards obedience—he obeys only when doing so secures something else of value. What explains the distribution of preferences among people to obey a law? I will sketch part of the answer that emerges from economic and psychological studies. Finding an answer is important because when laws are reasonably just and many citizens intrinsically prefer to obey them, government is easier, and life is better than when most citizens are indifferent towards obeying the law.
Tune measurement in the APS rings

The APS system will contain three rings. The first is a positron accumulator ring(PAR). Its function is to coalesce 24, 30-ns-long positron bunches into one 290-ps bunch. The second is the injector synchrotron (IS). It accelerates the 450-MeV positron bunches to 7 GeV for injection into the storage ring(SR). Five IS bunches are accumulated into one SR bucket to produce 17.5-nC, 60-ps bunches. Twenty buckets will be filled in the SR to give a current of 100 mA. >
Stochastic optimization in continuous time

List of figures Preface 1. Probability theory 2. Wiener processes 3. Stochastic calculus 4. Stochastic dynamic programming 5. How to solve it 6. Boundaries and absorbing barriers Appendix. Miscellaneous applications and exercises Bibliography Index.
Ebb: A DSL for Physical Simulation on CPUs and GPUs

Designing programming environments for physical simulation is challenging because simulations rely on diverse algorithms and geometric domains. These challenges are compounded when we try to run efficiently on heterogeneous parallel architectures. We present Ebb, a Domain-Specific Language (DSL) for simulation, that runs efficiently on both CPUs and GPUs. Unlike previous DSLs, Ebb uses a three-layer architecture to separate (1) simulation code, (2) definition of data structures for geometric domains, and (3) runtimes supporting parallel architectures. Different geometric domains are implemented as libraries that use a common, unified, relational data model. By structuring the simulation framework in this way, programmers implementing simulations can focus on the physics and algorithms for each simulation without worrying about their implementation on parallel computers. Because the geometric domain libraries are all implemented using a common runtime based on relations, new geometric domains can be added as needed, without specifying the details of memory management, mapping to different parallel architectures, or having to expand the runtime’s interface.We evaluate Ebb by comparing it to several widely used simulations, demonstrating comparable performance to handwritten GPU code where available, and surpassing existing CPU performance optimizations by up to 9 × when no GPU code exists.
A Simulated Annealing-Based Approach to Three-Dimensional Component Packing

This paper introduces a simulated annealing-based approach to three-dimensional component packing that employs simulated annealing to generate optimal solutions. Simulated annealing has been used extensively for two-dimensional layout of VLSI circuits; this research extends techniques developed for two-dimensional layout optimization to three-dimensional problems which are more representative of mechanical engineering applications. This research also provides a framework in which to solve general component layout problems.
Singular values and eigenvalues of tensors: a variational approach

We propose a theory of eigenvalues, eigenvectors, singular values, and singular vectors for tensors based on a constrained variational approach much like the Rayleigh quotient for symmetric matrix eigenvalues. These notions are particularly useful in generalizing certain areas where the spectral theory of matrices has traditionally played an important role. For illustration, we will discuss a multilinear generalization of the Perron-Frobenius theorem
Momentum constraint relaxation

Full relativistic simulations in three dimensions invariably develop runaway modes that grow exponentially and are accompanied by violations of the Hamiltonian and momentum constraints. Recently, we introduced a numerical method (Hamiltonian relaxation) that greatly reduces the Hamiltonian constraint violation and helps improve the quality of the numerical model. We present here a method that controls the violation of the momentum constraint. The method is based on the addition of a longitudinal component to the traceless extrinsic curvature ˜ Aij , generated by a vector potential wi ,a s outlined by York. The components of wi are relaxed to solve approximately the momentum constraint equations, slowly pushing the evolution towards the space of solutions of the constraint equations. We test this method with simulations of binary neutron stars in circular orbits and show that it effectively controls the growth of the aforementioned violations. We also show that a full numerical enforcement of the constraints, as opposed to the gentle correction of the momentum relaxation scheme, results in the development of instabilities that stop the runs shortly.
Decoherence without dissipation

The prototypical Schrodinger cat state, i.e., an initial state corresponding to two widely separated Gaussian wave packets, is considered. The decoherence time is calculated solely within the framework of elementary quantum mechanics and equilibrium statistical mechanics. This is at variance with common lore that irreversible coupling to a dissipative environment is the mechanism of decoherence. Here, we show that, on the contrary, decoherence can in fact occur at high temperature even for vanishingly small dissipation.  2001 Elsevier Science B.V. All rights reserved.
Analysis of young, small firms that have closed: delineating successful from unsuccessful closures

Abstract This study of small businesses created between 1989 and 1992, and then closed down between 1993 and 1996, reveals that owners often described their firms as “successful” when the closure decision was made. Decisions to discontinue operations of young firms are shaped by intertwined factors including opportunity costs, switching costs, and noneconomic considerations. Empirical investigation is undertaken to explain the seeming paradox of successful small-business closure. Alternative opportunities are identified as a key reason for choosing to discontinue successful firms: If something more attractive comes along, the owner may close down.
Analysis of the ultra-fast switching dynamics in a hybrid MOSFET/Driver

The turn-on dynamics of a power MOSFET during ultra-fast, ∼ ns, switching are discussed in this paper. The testing was performed using a custom hybrid MOSFET/Driver module, which was fabricated by directly assembling die-form components, power MOSFET and drivers, on a printed circuit board. By using die-form components, the hybrid approach substantially reduces parasitic inductance, which facilitates ultra-fast switching. The measured turn on time of the hybrid module with a resistive load is 1.2 ns with an applied voltage of 1000 V and drain current of 33 A. Detailed analysis of the switching waveforms reveals that switching behavior must be interpreted differently in the ultra-fast regime. For example, the gate threshold voltage to turn on the device is observed to increase as the switching time decreases. Further analysis and simulation of MOSFET switching behavior shows that the minimum turn on time scales with the product of the drain-source on resistance and drain-source capacitance, R DS(on) C OSS . This information will be useful in power MOSFET selection and gate driver design for ultra-fast switching applications.
DG quotients of DG categories

Abstract Keller introduced a notion of quotient of a differential graded category modulo a full differential graded subcategory which agrees with Verdier's notion of quotient of a triangulated category modulo a triangulated subcategory. This work is an attempt to further develop his theory.
Gold(I)-catalyzed amination of allylic alcohols with cyclic ureas and related nucleophiles.

A 1:1 mixture of [P(t-Bu)2-o-biphenyl]AuCl and AgSbF6 catalyzes the intermolecular amination of allylic alcohols with 1-methylimidazolidin-2-one and related nucleophiles that, in the case of γ-unsubstituted or γ-methyl-substituted allylic alcohols, occurs with high γ-regioselectivity and syn-stereoselectivity.
The Nature and Role of Feedback Text Comments in Online Marketplaces: Implications for Trust Building, Price Premiums, and Seller Differentiation

For online marketplaces to succeed and prevent a market of lemons, their feedback mechanism (reputation system) must differentiate among sellers and create price premiums for trustworthy sellers as returns to their reputation. However, the literature has solely focused on numerical (positive and negative) feedback ratings, alas ignoring the role of feedback text comments. These text comments are proposed to convey useful reputation information about a seller's prior transactions that cannot be fully captured with crude numerical ratings. Building on the economics and trust literatures, this study examines the rich content of feedback text comments and their role in building a buyer's trust in a seller's benevolence and credibility. In turn, benevolence and credibility are proposed to differentiate among sellers by influencing the price premiums that a seller receives from buyers. This paper utilizes content analysis to quantify over 10,000 publicly available feedback text comments of 420 sellers in eBay's online auction marketplace, and to match them with primary data from 420 buyers that recently transacted with these 420 sellers. These dyadic data show that evidence of extraordinary past seller behavior contained in the sellers' feedback text comments creates price premiums for reputable sellers by engendering buyer's trust in the sellers' benevolence and credibility (controlling for the impact of numerical ratings). The addition of text comments and benevolence helps explain a greater variance in price premiums (R2 = 50%) compared to the existing literature (R2 = 20%--30%). By showing the economic value of feedback text comments through trust in a seller's benevolence and credibility, this study helps explain the success of online marketplaces that primarily rely on the text comments (versus crude numerical ratings) to differentiate among sellers and prevent a market of lemon sellers. By integrating the economics and trust literatures, the paper has theoretical and practical implications for better understanding the nature and role of feedback mechanisms, trust building, price premiums, and seller differentiation in online marketplaces.
Cased-Based reasoning by human experts

The central insight that led to the field of Case-Based Reasoning was that human memory appears to be organized around individual episodic experiences (Schank, 1982; Kolodner, 1980). At the time, there were few empirical findings available that shed light on how humans encode, retrieve, and reason about complex experiences. In the twenty years since then, researchers in cognitive science have investigated both everyday autobiographical memory and the performance of human experts who process many individual cases within a domain, such as medical diagnosis. The results identify some important features of the case-based reasoning process in humans, and suggest new approaches to building computational models that may display similar capabilities.
Total Synthesis of Balanol and Designed Analogues

The total synthesis of balanol, a potent protein kinase C inhibitor isolated from the fungus Verticillium balanoides, is described. The hexahydroazepine fragment was prepared from D-serine through a sequence of reactions including the diastereoselective allylboration of a derived amino aldehyde and a base-induced 7-exo-tet ring closure as key steps. The benzophenone fragment was secured through the initial coupling of the two functionalised aromatic components through an ester linkage, followed by intramolecular nucleophilic attack of an aryl lithium derivative to form the desired ketone bridge. After coupling of the two balanol domains, the adoption of benzylderived protecting groups for the latent functionalities then allowed the liberation of balanol in a single step by catalytic hydrogenolysis. Finally, the newly developed synthetic strategy was applied to the synthesis of a variety of designed balanol analogues for biological evaluation.
A light and electron microscopic study of ectopic tendon and ligament formation induced by bone morphogenetic protein-13 adenoviral gene therapy.

Object. Bone morphogenetic proteins (BMPs) are involved in the growth and development of many tissues, but it is their role in skeletal development and their unique ability to induce ectopic and orthotopic osteogenesis that have attracted the greatest interest. Expression of the BMP-13 gene is predominantly localized to hypertrophic chondrocytes in regions of endochondral bone formation during development, as well as in mature articular cartilage in the adult. In addition, the application of BMP-13 on a collagen carrier induces neotendon/neoligament formation when delivered subcutaneously or intramuscularly in rodents. The aim of the present study was to determine the histological and ultrastructural changes that occur after the intramuscular injection of a first-generation BMP-13 adenoviral vector. Methods. Athymic nude rats were injected with 3.75 × 1010 plaque-forming units of adenovirus (Ad)-BMP-13 or Ad-β-galactosidase in the thigh musculature, and the region was examined using light and electron mic...
Profit Neutrality in Licensing: The Boundary Between Antitrust Law and Patent Law

From the antitrust case law that governs restrictions on patent licenses, we derive three unifying principles: just reward, profit neutrality and minimalism. The just-reward principle holds that the patentholder's profits should be earned, if at all, from the social value created by his invention. Profit neutrality holds that patent rewards should not depend on the rightholder's ability to work the patent himself. Minimalism holds that licensing contracts should not use more restrictive terms than required for neutrality. We discuss how these principles determine which patent license restrictions should and should not be acceptable from an antitrust perspective. We also compare these principles and the per se rules that follow from them to the potential benefits and drawbacks likely to be encountered under a rule of reason approach.
Shellable complexes from multicomplexes

Suppose a group G acts properly on a simplicial complex Γ. Let l be the number of G-invariant vertices, and p 1,p 2,?,p m be the sizes of the G-orbits having size greater than 1. Then Γ must be a subcomplex of $\varLambda=\varDelta ^{l-1}*\partial \varDelta ^{p_{1}-1} *\cdots*\partial \varDelta ^{p_{m}-1}$ . A result of Novik gives necessary conditions on the face numbers of Cohen---Macaulay subcomplexes of ?. We show that these conditions are also sufficient, and thus provide a complete characterization of the face numbers of these complexes.
A high-performance integrated K-band diplexer

This paper describes the design and measurement of a planar diplexer integrated on a single silicon substrate. The diplexer channels are 5% and 6.5% relative bandwidth at 28 and 31 GHz, respectively. The diplexer is based on a micropackaged membrane supported capacitively coupled microstrip structure and is 1.5 cm/spl times/1.6 cm and only 1.4 mm thick. The measured insertion loss is 1.4 dB (5%) and 0.9 dB (6.5%) for the two channels with better than 35 dB isolation in the 28 GHz band and better than 50 dB isolation in the 31 GHz band. The measured results include all transition and packaging effects. The diplexer has coplanar-waveguide ports and can easily be integrated with other elements such as planar antennas, low-noise amplifier, and power amplifiers.
Dopamine modulation of prefrontal delay activity-reverberatory activity and sharpness of tuning curves

Abstract Recent electrophysiological experiments have shown that dopamine (D1) modulation of pyramidal cells in prefrontal cortex reduces spike frequency adaptation and enhances NMDA transmission. Using four models, from multicompartmental to integrate-and-fire, we examine the effects of these modulations on sustained (delay) activity in a reverberatory network. We find that D1 modulation may enable robust network bistability yielding selective reverberation among cells that code for a particular item or location. We further show that the tuning curve of such cells is sharpened, and that signal-to-noise ratio is increased. We postulate that D1 modulation affects the tuning of “memory fields” and yield efficient distributed dynamic representations.
On Landau’s solutions of the Navier–Stokes equations

A special class of solutions of the n-dimensional steady-state Navier–Stokes equations is considered. Bibliography: 23 titles.
Accuracy and Efficiency Assessments for a Weak Statement CFD Algorithm for High-Speed Aerodynamics

A bilinear finite element, implicit Runge-Kutta spacetime discretization has been established for an aerodynamics weak statement CFD algorithm. The algorithm admits realgas effects simulation, for reliable hypersonic flow characterization, via an equilibrium reacting air model. The terminal algebraic system is solved using an efficient blocktridiagonal quasi-Newton linear algebra procedure that employs tensor matrix product factorizations within a lexicographic mesh-sweeping protocol. A block solutionadaptive remeshing, for totally arbitrary convex elements, is also utilized to facilitate accurate shock and/or boundary layer flow resolution. Numerical validations are presented for representative benchmark supersonic-hypersonic aerodynamics problem statements.
Performance of Phase Modulated Systems Using Fully Saturated Power Amplifiers

This paper studies the performances of BPSK and QPSK modulations amplified by fully saturated power amplifiers. To achieve better performance, both convolutional code and Turbo code are used. Viterbi decoding and iterative turbo decoding are employed in the receiver, respectively. Simulation results show that good BER performance can be achieved when signal is amplified by fully saturated power amplifiers and transmitted through AWGN channel. The SNR degradation is 0.7 dB for BPSK and 0.3-0.4 dB for QPSK at BER= 10− 5.
Charged‐particle detection using storage phosphor crystals

We propose a detector of charged particles based on photostimulated luminescence (PSL) of single crystals. Such a detector potentially allows for high space resolution (tens of microns) over a large area and excellent pattern recognition (it is non-projective). Potentially, it is competitive with existing detectors both in price and performance. The detectors may be used in neutrino or other low-rate experiments. We demonstrate detection of a particles with an average signal of 190 photoelectrons and estimate a minimum-ionizing particle to yield 50 photoelectrons per millimeter of track. The noise level of 15 photoelectrons RMS is limited by technical issues, and there is a clear perspective to reduce it greatly.
Degrees of freedom of MIMO X networks: Spatial scale invariance, one-sided decomposability and linear feasibility

We show that an M × N user MIMO X network with A antennas at each node has A (MN/M+N−1) degrees of freedom (DoF), thus settling the spatial scale invariance conjecture (scaling the number of antennas at each node by a constant factor will scale the total DoF by the same factor) for this class of networks. The previously known best general DoF inner bound, inspired by the K user interference channel, was based on the decomposition of every transmitter and receiver into multiple single antenna nodes, transforming the network into an AM × AN user SISO X network. While such a decomposition is DoF optimal for the K user interference channel, a gap remained between the best inner and outer bound for the MIMO X channel. Here we close this gap with the new insight that the MIMO X network is only one-sided decomposable, i.e., either all the transmitters or all the receivers (but not both) can be decomposed by splitting multiple antenna nodes into multiple single antenna nodes without loss of DoF. The result is extended to SIMO and MISO X networks as well and in each case the DoF results satisfy the spatial scale invariance property. In addition, the feasibility of linear interference alignment is investigated based only on spatial beamforming without symbol extensions. Similar to MIMO interference networks, we show that when the problem is improper, it is infeasible.
Fast TeV variability from misaligned minijets in the jet of M87

The jet of the radio galaxy M87 is misaligned, resulting in a Doppler factor δ~1 for emission of plasma moving parallel to the jet. This makes the observed fast TeV flares on time-scales of t v ~ 5 R g /c harder to understand as emission from the jet. In previous work, we have proposed a jets-in-a-jet model for the ultrafast TeV flares with t v « R g /c seen in Mrk 501 and PKS 2155-304. Here, we show that about half of the minijets beam their emission outside the jet cone. Minijets emitting off the jet axis result in rapidly evolving TeV (and maybe lower energy) flares that can be observed in nearby radio galaxies. The TeV flaring from M87 fits well into this picture, if M87 is a misaligned blazar.
An optimizing design strategy for multiple model adaptive estimation and control

A method is proposed for designing multiple model adaptive estimators to provide combined state and parameter estimation in the presence of an uncertain parameter vector. It is assumed that the parameter varies over a continuous region and a finite number of constant gain filters are available for the estimation. The estimator elemental filters are shown by minimizing a cost functional representing the average state prediction error autocorrelation, with the average taken as the true parameter ranges over the admissible parameter set. An analogous method is proposed for designing multiple model adaptive regulators to provide stabilizing control in the presence of an uncertain parameter vector by minimizing a cost functional representing the average regulation error autocorrelation, with the average taken as the true parameter ranges over the admissible parameter set. An example is used to demonstrate the improvement in performance over previously accepted design methods. >
BELIEFS ABOUT OTHER‐REGARDING PREFERENCES IN A SEQUENTIAL PUBLIC GOODS GAME

Experimental evidence is used to deduce players' beliefs about their opponents' concern for others. The experiment is a sequential public good provision game with a provision point and two different refund rules. A theory is constructed to show how early contributions should change with the refund rule depending on the first mover's beliefs about subsequent players' other-regarding preferences. The evidence rejects the hypothesis that early players believe that their opponents are inequality averse and also rejects the hypothesis that early players are concerned with security. The evidence is consistent with beliefs in spite, reciprocity, or a concern for security. (JEL H41, C90, D63, D64)
Price dynamics in an exchange economy

The pure exchange model is the foundation of the neoclassical theory of value, yet equilibrium predictions and models of price adjustment for this model remained untested prior to the experiment reported in this paper. With the exchange economy replicated several times, prices and allocations converge sharply to the competitive equilibrium in continuous double auction (CDA) trading. Convergence is evaluated by comparing the extent of price adjustment within each market replication (or trading period) to the extent of adjustment across trading periods: most observed price adjustment occurs within trading periods, so price adjustment data are evaluated with the Hahn process model (Hahn and Negishi (1962)), which is a disequilibrium model of within-period trades. Estimation demonstrates that the model is consistent with observed price paths within each period of the exchange economy. The model is augmented with an additional assumption - based on observations from this experiment - that the initial trade price in period t+1 is randomly drawn from the interval between the minimum and maximum trade prices in period t. The estimated within-period adjustment rule, combined with this across-period adjustment rule, generates price paths similar to data from an experiment session.
Stability of viscoelastic control systems

Classical root locus plot analysis is adapted to some one-dimensional, controlled, distributed, viscoelastic structures. The constitutive law that is used for the viscoelastic material may be modeled with fractional order derivatives provided the control law(s) involve similar derivatives. Two sample one-dimensional structures and control systems are used to introduce the approach. A partial-differential-equation representation of each structure is used as well as Ritz approximation. The effect of error due to approximation on stability conclusions is discussed in the context of this comparison. >
Fulde-Ferrell pairing instability in spin-orbit coupled Fermi gas

We consider finite-momentum pairing of a superfluid ultracold Fermi gas subject to spin-orbit coupling and an effective Zeeman field. Based on our two-body and mean-field many-body calculations, we show that the Fulde-Ferrell-type superfluid dominates in both zero- and finite-temperature phase diagrams. We examine the origin and properties of this novel phase systematically.
Room temperature synthesis of metal-organic frameworks: MOF-5, MOF-74, MOF-177, MOF-199, and IRMOF-0

Abstract Room temperature synthesis of metal-organic frameworks (MOFs) has been developed for four well-known MOFs: MOF-5, MOF-74, MOF-177, and MOF-199. A new isoreticular metal framework (IRMOF), IRMOF-0, having the same cubic topology as MOF-5, has been synthesized from acetylenedicarboxylic acid using this method to accommodate the thermal sensitivity of the linker. Despite acetylenedicarboxylate being the shortest straight linker that can be made into an IRMOF, IRMOF-0 forms as a doubly interpenetrating structure, owing to the rod-like nature of the linker.