cssi/SciSciGPT-SciSciNet huggingface dataset:
Structural Damage Detection Using Virtual Passive Controllers

This paper presents novel approaches for structural damage detection which uses the virtual passive controllers attached to structures, where passive controllers are energy dissipative devices and thus guarantee the closed-loop stability. The use of the identified parameters of various closed-loop systems can solve the problem that reliable identified parameters, such as natural frequencies of the open-loop system may not provide enough information for damage detection. Only a small number of sensors are required for the proposed approaches. The identified natural frequencies, which are generally much less sensitive to noise and more reliable than the identified natural frequencies, are used for damage detection. Two damage detection techniques are presented. One technique is based on the structures with direct output feedback controllers while the other technique uses the second-order dynamic feedback controllers. A least-squares technique, which is based on the sensitivity of natural frequencies to damage variables, is used for accurately identifying the damage variables.
Translating non-standard extensions to standard Pascal

Extensions to a programming language are often introduced by individual implementors for a variety of reasons. In some cases, a new construct may allow the programmer to take advantage of a unique hardware or software feature in the specific system. In other cases, the application for which the language is frequently employed may warrant simpler and more efficient constructs. Whatever the motive, extensions, in general, severely limit portability of programs. Often it is necessary to manually translate non-standard features before a program can be successfully adapted to a new environment. If we must live with such extensions at all, ideally we would like to be able to translate all extensions automatically to make the adaptation expedient and reliable.
Intramolecularly competitive anionic oxy-cope rearrangements

Abstract Two examples of the title reaction are described. While the kinetically preferred pathway for 2 utilizes the vinyl substituent, that for 16 skirts this option completely. To a great extent, these biases are a function of the structural features inherent to these alochols.
Intent specifications: an approach to building human-centered specifications

This paper examines and proposes an approach to writing software specifications, based on research in systems theory, cognitive psychology and human-machine interaction. The goal is to provide specifications that support human problem solving and the tasks that humans must perform in software development and evolution. A type of specification, called intent specifications, is constructed upon this underlying foundation.
General microwave-assisted protocols for the expedient synthesis of quinoxalines and heterocyclic pyrazines

Abstract Functionalized quinoxalines and heterocyclic pyrazines are expediently prepared in excellent yields (69–99%) from common 1,2-diketone intermediates under microwave irradiation. In addition to being general for a variety of aryl/heteroaryl 1,2-diamines and 1,2-diketones, this protocol suppresses the formation of polymeric species, characteristic of traditional thermal conditions.
Green synthesis of metal nanoparticles: Biodegradable polymers and enzymes in stabilization and surface functionalization

Current breakthroughs in green nanotechnology are capable of transforming many of the existing processes and products that enhance environmental quality, reduce pollution, and conserve natural and non-renewable resources. Successful use of metal nanoparticles and nanocomposites in various catalytic applications, electronics, biology and biomedical applications, material science, physics, environmental remediation and interdisciplinary fields as well as their toxicity essentially depends on the structural features such as size, shape, composition and the surface chemistry of nanomaterials. Moreover, to prolong the life span of metal nanoparticles and avoid undesired effects such as aggregation in aqueous solutions and organic solvents, to prevent contamination of the environment as well as to reuse and recycle nanoparticles, it is vital to select stabilizing agents and functionalization pathways that are environmentally friendly, non toxic and easy to implement. In recent years, stabilization and surface functionalization of metal nanoparticles became ‘greener’ to the extent that biocompatible stabilizing agents, e.g. biodegradable polymers and enzymes among others were introduced. These agents were able to produce a great variety of extremely stable spherical-, rod- or flower-shaped metal nanoparticles that opened up vast opportunities for their utilization and potential mass production. This review summarizes the state-of-the-art in the use of biocompatible and biodegradable homo- and copolymers as well as enzymes for the production of stable, environmentally benign, selective and active metal nanoparticles for desired applications.
Social Cognitive Neuroscience: A Review of Core Processes

Social cognitive neuroscience examines social phenomena and processes using cognitive neuroscience research tools such as neuroimaging and neuropsychology. This review examines four broad areas of research within social cognitive neuroscience: (a) understanding others, (b) understanding oneself, (c) controlling oneself, and (d ) the processes that occur at the interface of self and others. In addition, this review highlights two core-processing distinctions that can be neurocognitively identified across all of these domains. The distinction between automatic versus controlled processes has long been important to social psychological theory and can be dissociated in the neural regions contributing to social cognition. Alternatively, the differentiation between internally-focused processes that focus on one’s own or another’s mental interior and externally-focused processes that focus on one’s own or another’s visible features and actions is a new distinction. This latter distinction emerges from social cognitive neuroscience investigations rather than from existing psychological theories demonstrating that social cognitive neuroscience can both draw on and contribute to social psychological theory.
A Comparison of Multicast Pull Models

We consider the setting of a web server that receives requests for documents from clients, and returns the requested documents over a multicast/broadcast channel. We compare the quality of service (QoS) obtainable by optimal schedules under various models of the capabilities of the server and the clients to send and receive segments of a document out of order. We show that allowing the server to send segments out of order does not improve any reasonable QoS measure. However, the ability of the clients to receive data out of order can drastically improve the achievable QoS under some, but not all, reasonable/common QoS measures.
Expression of tumour-specific antigens underlies cancer immunoediting

Cancer immunoediting is a process by which immune cells, particularly lymphocytes of the adaptive immune system, protect the host from the development of cancer and alter tumour progression by driving the outgrowth of tumour cells with decreased sensitivity to immune attack. Carcinogen-induced mouse models of cancer have shown that primary tumour susceptibility is thereby enhanced in immune-compromised mice, whereas the capacity for such tumours to grow after transplantation into wild-type mice is reduced. However, many questions about the process of cancer immunoediting remain unanswered, in part because of the known antigenic complexity and heterogeneity of carcinogen-induced tumours. Here we adapted a genetically engineered, autochthonous mouse model of sarcomagenesis to investigate the process of cancer immunoediting. This system allows us to monitor the onset and growth of immunogenic and non-immunogenic tumours induced in situ that harbour identical genetic and histopathological characteristics. By comparing the development of such tumours in immune-competent mice with their development in mice with broad immunodeficiency or specific antigenic tolerance, we show that recognition of tumour-specific antigens by lymphocytes is critical for immunoediting against sarcomas. Furthermore, primary sarcomas were edited to become less immunogenic through the selective outgrowth of cells that were able to escape T lymphocyte attack. Loss of tumour antigen expression or presentation on major histocompatibility complex I was necessary and sufficient for this immunoediting process to occur. These results highlight the importance of tumour-specific-antigen expression in immune surveillance, and potentially, immunotherapy.
The Wage Impact of the Marielitos: A Reappraisal

This article brings a new perspective to the analysis of the wage effects of the Mariel boatlift crisis, in which an estimated 125,000 Cuban refugees migrated to Florida between April and October, 1980. The author revisits the question of wage impacts from such a supply shock, drawing on the cumulative insights of research on the economic impact of immigration. That literature shows that the wage impact must be measured by carefully matching the skills of the immigrants with those of the incumbent workforce. Given that at least 60% of the Marielitos were high school dropouts, this article specifically examines the wage impact for this low-skill group. This analysis overturns the prior finding that the Mariel boatlift did not affect Miami’s wage structure. The wage of high school dropouts in Miami dropped dramatically, by 10 to 30%, suggesting an elasticity of wages with respect to the number of workers between −0.5 and −1.5.
Temporal and Spatial Variations of Heliospheric X-Ray Emissions Associated with Charge Transfer of the Solar Wind with Interstellar Neutrals

A simple model has been developed that demonstrates that heliospheric X-ray emission can account for about 25%–50% of observed soft X-ray background intensities. Similar to cometary soft X-ray emission, these X-rays are thought to be produced in the heliosphere due to charge transfer collisions between heavy solar wind ions and interstellar neutrals. A more complex model has now been developed to take into account temporal and spatial variations of the solar wind and interstellar neutrals. Measured time histories of the solar wind proton flux are used in the model and the results are compared with the ‘long-term enhancements’ in the soft X-ray background measured by ROSAT for the same time period.
Markovian loop soups: permanental processes and isomorphism theorems

We construct loop soups for general Markov processes without transition densities and show that the associated permanental process is equal in distribution to the loop soup local time. This is used to establish isomorphism theorems connecting the local time of the original process with the associated permanental process. Further properties of the loop measure are studied.
The 3,4-O-Carbonate Protecting Group as a β-Directing Group in Rhamnopyranosylation in Both Homogeneous and Heterogeneous Glycosylations As Compared to the Chameleon-like 2,3-O-Carbonates

It is demonstrated that the β-selectivity observed in the insoluble silver salt mediated couplings of 2,3-O-carbonate-protected rhamnosyl bromides is uniquely due to the heterogeneous nature of the reaction. In homogeneous solution these same donors are α-selective, a fact that is attributed to the half-chair conformation of these substances which reduces the energy barrier to oxacarbenium ion formation. It is suggested that the 2,3-O-carbonate group be dubbed torsionally arming in the manno- and rhamnopyranose series. When the carbonate group is removed to the 3,4-O-position a β-selective system is formed, in both homogeneous and heterogeneous conditions, and it is demonstrated that this selectivity arises from the combination of the electron-withdrawing nature of the carbonate and its inability to take part in neighboring participation.
A resource-based theory of sustainable rents

This paper summarizes and comments on Conner (1991) that contributes to the strategic management area by providing an historical comparison of resource-based theory and five schools of thought within industrial organization economics. Conner (1991) argues that the fundamental distinction between resource-based theory and transaction costs theory is that resource-based theory focuses on the deployment and combination of specific inputs while transaction costs theory focuses on the avoidance of opportunism. I offer three responses to this claim. First, Conner’s distinction was not central to the resource-based literature at the time the article was published. Second, I raise concerns about building a resource-based theory of the firm that assumes away the problems of opportunistic behavior. Third, I offer an alternative view of the fundamental similarities and differences between resource-based theory and transaction costs theory.
Olson's Logic of Collective Action at fifty

In the 50 years since its publication, Mancur Olson’s Logic of Collective Action has had an enormous impact on the academic literature in both economics and political science. In this review essay, I discuss Olson’s work in light of the ensuing research, particularly developments in the theoretical literature. Much of the discussion focuses on the group-size paradox as applied to politics, i.e., the extent to which the group-size paradox can explain why the interests of some groups are better represented in the political process than others. I also discuss selective incentives with an emphasis on the byproduct mechanism under which a firm sells a private good and uses the resulting profits to provide a public good.
Spectral and Quantum Dynamical Properties of the Weakly Coupled Fibonacci Hamiltonian

We consider the spectrum of the Fibonacci Hamiltonian for small values of the coupling constant. It is known that this set is a Cantor set of zero Lebesgue measure. Here we study the limit, as the value of the coupling constant approaches zero, of its thickness and its Hausdorff dimension. We prove that the thickness tends to infinity and, consequently, the Hausdorff dimension of the spectrum tends to one. We also show that at small coupling, all gaps allowed by the gap labeling theorem are open and the length of every gap tends to zero linearly. Moreover, for a sufficiently small coupling, the sum of the spectrum with itself is an interval. This last result provides a rigorous explanation of a phenomenon for the Fibonacci square lattice discovered numerically by Even-Dar Mandel and Lifshitz. Finally, we provide explicit upper and lower bounds for the solutions to the difference equation and use them to study the spectral measures and the transport exponents.
Mixed robust/average submodular partitioning: fast algorithms, guarantees, and applications

We investigate two novel mixed robust/average-case submodular data partitioning problems that we collectively call Submodular Partitioning. These problems generalize purely robust instances of the problem, namely max-min submodular fair allocation (SFA) [12] and min-max submodular load balancing (SLB) [25], and also average-case instances, that is the submodular welfare problem (SWP) [26] and submodular multiway partition (SMP) [5]. While the robust versions have been studied in the theory community [11, 12, 16, 25, 26], existing work has focused on tight approximation guarantees, and the resultant algorithms are not generally scalable to large real-world applications. This is in contrast to the average case, where most of the algorithms are scalable. In the present paper, we bridge this gap, by proposing several new algorithms (including greedy, majorization-minimization, minorization-maximization, and relaxation algorithms) that not only scale to large datasets but that also achieve theoretical approximation guarantees comparable to the state-of-the-art. We moreover provide new scalable algorithms that apply to additive combinations of the robust and average-case objectives. We show that these problems have many applications in machine learning (ML), including data partitioning and load balancing for distributed ML, data clustering, and image segmentation. We empirically demonstrate the efficacy of our algorithms on real-world problems involving data partitioning for distributed optimization (of convex and deep neural network objectives), and also purely unsupervised image segmentation.
Measuring Teacher Implementation of the BEST in CLASS Intervention Program and Corollary Child Outcomes

This study is part of a larger randomized efficacy trial examining the impact of Behavioral, Emotional, and Social Training: Competent Learners Achieving School Success (BEST in CLASS), a Tier 2 intervention that targets the prevention of emotional/behavioral disorders in young, high risk children. In this investigation, we examined teachers’ implementation and maintenance of instructional practices in early childhood classrooms and the corollary relationships between teacher implementation of the specific instructional practices associated with BEST in CLASS and child engagement and problem behaviors. Fifty-three teachers (26 in treatment and 27 in comparison) and 130 preschool-aged children (66 in treatment and 64 in comparison) participated. Findings indicated that teachers’ who received training and coaching in the BEST in CLASS intervention increased their use of specific instructional practices in comparison with teachers in the control condition. In addition, children whose teachers’ received the B...
Comprehensive method based on model free method and IKP method for evaluating kinetic parameters of solid state reactions.

This article presents, firstly, a short review of methods for evaluating kinetic parameters of solid state reactions and a critical analysis of the isoconversional principle of model free methods. It shows theoretically that the activation energy for complex reactions is not only a function of the reaction degree but also of heating programs, and points out that any method that attempts to extract the dependences of activation energy on conversion degree without considering the dependences of heating programs is problematic. Then an analysis is given of the invariant kinetic parameters (IKP) method and recommends an incremental version of it. Based on the incremental IKP method and model free method, a comprehensive method is proposed that predicts the degree of the dependences of activation energy on heating programs, selects reliable values of activation energy and extracts the values of variable pre-exponential factor. This comprehensive method is tested using both simulation data and experimental data, the results of which show it can not only give reliable values of kinetic parameters but also be helpful in explaining inconsistencies of kinetic results in solid state reactions. V C 2012 Wiley Periodicals, Inc.
Global Competitive Strategy

List of figures List of tables Preface Acknowledgements Introduction: the global challenge 1. The global mosaic 2. Global strategic analysis 3. Global competitive advantage 4. Global competitive strategy 5. Global investment strategy: choosing the best mix of transactions and investment 6. The global business organization 7. Lenovo: entering global competition 8. Cemex: making global markets 9. Dairy farm: regional retail strategy 10. Danone: organizing for global competition Conclusion.
Auctions for Split-Award Contracts

The buyer of a homogeneous input divides his input requirements into two contracts that are awarded to different suppliers. He uses a sequential second-price auction to award a primary and a secondary contract. With a fixed number of suppliers the buyer pays a higher expected price than with a sole-source auction. The premium paid to the winner of the secondary contract must also be paid to the winner of the primary contract as an opportunity cost. When entry is endogenous, we identify the conditions under which a secondary contract can increase the number of suppliers and lower the expected price.
Possible world partition sequences: a unifying framework for uncertain reasoning

When we work with information from multiple sources, the formalism each employs to handle uncertainty may not be uniform. In order to be able to combine these knowledge bases of different formats, we need to first establish a common basis for characterizing and evaluating the different formalisms, and provide a semantics for the combined mechanism. A common framework can provide an infrastructure for building an integrated system, and is essential if we are to understand its behavior. We present a unifying framework based on an ordered partition of possible worlds called partition sequences, which corresponds to our intuitive notion of biasing towards certain possible scenarios when we are uncertain of the actual situation. We show that some of the existing formalisms, namely, default logic, autoepistemic logic, probabilistic conditioning and thresholding (generalized conditioning), and possibility theory can be incorporated into this general framework.
Co2 technology platform: An important tool for environmental problem solving

CO(2) is a good solvent for many substances when compressed into its liquid or supercritical fluid state. Above the critical temperature and critical pressure (T(c)=31 degrees C, P(c)=73.8 bar, see Figure 1 for the phase diagram for CO(2)), CO(2) has both gaslike viscosities and liquidlike densities. These moderate critical conditions allow CO(2) to be used within safe commercial and laboratory operating conditions. Small changes in temperature and pressure cause dramatic changes in the density, viscosity, and dielectric properties of CO(2), making it a tunable solvent that can be tailored for various applications. Combined, these unique properties make CO(2) a "solvent of choice" for the new millennium.
The Local Stellar Velocity Field via Vector Spherical Harmonics

We analyze the local field of stellar tangential velocities for a sample of 42,339 nonbinary Hipparcos stars with accurate parallaxes, using a vector spherical harmonic formalism. We derive simple relations between the parameters of the classical linear model (Ogorodnikov-Milne) of the local systemic field and low-degree terms of the general vector harmonic decomposition. Taking advantage of these relationships, we determine the solar velocity with respect to the local stars of (V(sub X), V(sub Y), V(sub Z)) (10.5, 18.5, 7.3) +/- 0.1 km s(exp -1) not corrected for the asymmetric drift with respect to the local standard of rest. If only stars more distant than 100 pc are considered, the peculiar solar motion is (V(sub X), V(sub Y), V(sub Z)) (9.9, 15.6, 6.9) +/- 0.2 km s(exp -1). The adverse effects of harmonic leakage, which occurs between the reflex solar motion represented by the three electric vector harmonics in the velocity space and higher degree harmonics in the proper-motion space, are eliminated in our analysis by direct subtraction of the reflex solar velocity in its tangential components for each star. The Oort parameters determined by a straightforward least-squares adjustment in vector spherical harmonics are A=14.0 +/- 1.4, B=13.1 +/- 1.2, K=1.1 +/- 1.8, and C=2.9 +/- 1.4 km s(exp -1) kpc(exp -1). The physical meaning and the implications of these parameters are discussed in the framework of a general linear model of the velocity field. We find a few statistically significant higher degree harmonic terms that do not correspond to any parameters in the classical linear model. One of them, a third-degree electric harmonic, is tentatively explained as the response to a negative linear gradient of rotation velocity with distance from the Galactic plane, which we estimate at approximately -20 km s(exp -1) kpc(exp -1). A similar vertical gradient of rotation velocity has been detected for more distant stars representing the thick disk (z greater than 1 kpc), but here we surmise its existence in the thin disk at z less than 200 pc. The most unexpected and unexplained term within the Ogorodnikov-Milne model is the first-degree magnetic harmonic, representing a rigid rotation of the stellar field about the axis -Y pointing opposite to the direction of rotation. This harmonic comes out with a statistically robust coefficient of 6.2 +/- 0.9 km s(exp -1) kpc(exp -1) and is also present in the velocity field of more distant stars. The ensuing upward vertical motion of stars in the general direction of the Galactic center and the downward motion in the anticenter direction are opposite to the vector field expected from the stationary Galactic warp model.
NEW PRODUCT DEVELOPMENT PRACTICES OF THE U.S. CONFECTIONERY MANUFACTURERS: 2006 SURVEY PRELIMINARY FINDINGS

This paper reports on the new product development practices of the U.S. confectionery manufacturers. A mail survey method was used to collect data. Confectionery manufacturers, specifically, new product development managers listed in the Thomas Food and Beverage Marketplace were contacted. A donation to charity on behalf of the respondents was used as an incentive to participate in the study. Analyses of the data, including graphical, descriptive, cross-tabulation, and correlation were conducted using SAS and SPSS econometric softwares and Microsoft Excel. Preliminary findings of the survey are reported in this paper.
Teratogen update: Reproductive risks of leflunomide (Arava™); A pyrimidine synthesis inhibitor: counseling women taking leflunomide before or during pregnancy and men taking leflunomide who are contemplating fathering a child

Arava™ (leflunomide) is a pyrimidine synthesis inhibitor used in the treatment of active rheumatoid arthritis (RA). The chemical name for leflunomide is N-(49-trifluoromethylphenyl)-5-methylisoxazole-4-carboxamide. Because the drug has been successful in the treatment of rheumatoid arthritis, it is being widely prescribed. In spite of the clear warning that the drug should not be prescribed for pregnant women, approximately 30 women have become pregnant while taking leflunomide as of December 1999. This commentary was prepared to aid teratology counselors and genetic counselors who might be contacted by physicians or patients about the risk of leflunomide exposure during pregnancy. Before the subject of risk is discussed, it is important to understand the results of preclinical testing, phamacokinetic studies, and clinical studies that are available.
Differences in Job Satisfaction among Suburban and Inner-City High School Physical Education Faculty

Abstract The purpose of the present investigation was to determine whether faculty in suburban and inner-city schools differ with respect to job satisfaction. Subjects were 49 physical education faculty in three inner-city and three suburban Los Angeles-area high schools. The Job Description Index (JDI) was used to evaluate four aspects of job satisfaction: work, colleagues, supervision, and pay. Correlations were calculated among all pairs of job satisfaction values for suburban and inner-city subjects. Results yielded highly significant differences between intrinsic and extrinsic aspects of job satisfaction. These data indicated that subjects dissatisfied with intrinsic job satisfaction factors (work, colleagues, supervision) were satisfied with the extrinsic aspect (pay), and vice versa. The suburban subjects scored high on the intrinsic scales and low on the extrinsic aspect. Inner-city faculty yielded low intrinsic and high extrinsic scores.
Who Wants To Deliberate—And Why?

Interest in deliberative theories of democracy has grown tremendously among political theorists, political scientists, activists, and even government officials. Many scholars, however, are skeptical that it is a practically viable theory, even on its own terms. They argue (inter alia) that most people dislike politics and that deliberative initiatives would amount to a paternalistic imposition. Using two large national samples investigating people's hypothetical willingness to deliberate and their actual participation in response to a real invitation to deliberate with their member of Congress, we find that (1) willingness to deliberate in the United States is much more widespread than expected, and (2) it is precisely those people less likely to participate in traditional partisan politics who are most interested in deliberative participation. They are attracted to such participation as a partial alternative to “politics as usual.”
Multidisciplinary Research: Strategies for Assessing Chemical Mixtures to Reduce Risk of Exposure and Disease

Abstract The Precautionary Principle is founded on the use of comprehensive, coordinated research to protect human health in the face of uncertain risks. Research directed at key data gaps may significantly reduce the uncertainty underlying the complexities of assessing risk to mixtures. The National Institute of Environmental Health Sciences (NIEHS) has taken a leadership role in building the scientific infrastructure to address these uncertainties. The challenge is to incorporate the objectives as defined by the Precautionary Principle with the knowledge gained in understanding the multifactorial nature of gene-environment interactions. Through efforts such as the National Center for Toxicogenomics, the National Toxicology Program, and the Superfund Basic Research Program, NIEHS is translating research findings into public health prevention strategies using a 3-pronged approach: (1) identify/evaluate key deviations from additivity for mixtures; (2) develop/apply/link advanced technologies and bioinforma...
Substrate Gating of Contact Resistance in Graphene Transistors

Metal contacts have been identified to be a key technological bottleneck for the realization of viable graphene electronics. Recently, it has been observed that for structures that possess both a top and a bottom gate, the electron-hole conductance asymmetry can be modulated by the bottom gate. In this paper, we explain this observation by postulating the presence of an effective thin interfacial dielectric layer between the metal contact and the underlying graphene. Electrical results from quantum transport calculations accounting for this modified electrostatics corroborate well with the experimentally measured contact resistances. This paper indicates that the engineering of a metal-graphene interface is a crucial step toward reducing the contact resistance for high-performance graphene transistors.
Inference in probabilistic logic programs with continuous random variables

Probabilistic Logic Programming (PLP), exemplified by Sato and Kameya's PRISM, Poole's ICL, Raedt et al.'s ProbLog and Vennekens et al.'s LPAD, is aimed at combining statistical and logical knowledge representation and inference. However, the inference techniques used in these works rely on enumerating sets of explanations for a query answer. Consequently, these languages permit very limited use of random variables with continuous distributions. In this paper, we present a symbolic inference procedure that uses constraints and represents sets of explanations without enumeration. This permits us to reason over PLPs with Gaussian or Gamma-distributed random variables (in addition to discrete-valued random variables) and linear equality constraints over reals. We develop the inference procedure in the context of PRISM; however the procedure's core ideas can be easily applied to other PLP languages as well. An interesting aspect of our inference procedure is that PRISM's query evaluation process becomes a special case in the absence of any continuous random variables in the program. The symbolic inference procedure enables us to reason over complex probabilistic models such as Kalman filters and a large subclass of Hybrid Bayesian networks that were hitherto not possible in PLP frameworks.
Unit-Contingent Power Purchase Agreement and Asymmetric Information About Plant Outage

This paper analyzes a unit-contingent power purchase agreement between an electricity distributor and a power plant. Under such a contract the distributor pays the plant a fixed price if the plant is operational and nothing if plant outage occurs. Pricing a unit-contingent contract is complicated by the fact that the plant's true status is its private information. The difference between the electricity spot price and the unit-contingent contract price provides an incentive for the plant to misreport its status and earn profit at the distributor's expense. To prevent misreporting, the distributor may inspect the plant and levy penalties if misreporting is discovered. We find that some type of misreporting under certain circumstances can benefit both the plant and the distributor, because it serves as a risk-allocation mechanism between the two parties. We show that such a risk-allocation mechanism is equivalent to using state-contingent options and prohibiting misreporting.
Outcome in the Management of Penetrating Venous Injury

The authors report on the management of 33 patients with penetrating venous injuries, 25 due to gunshot wounds and 8 due to stab wounds. During the period of this study we treated 35 venous injuries and two patients, both following femoral artery and vein repairs and limb salvage were lost to follow-up and are excluded. Thirty-two had associ ated thoracic, intraabdominal, or arterial injuries. Duplex imaging was performed in 14 patients and venography in 12. They assessed all 27 survivors for postoperative sequelae. Mean follow-up time was twenty months, ranging from three months to three years. Four patients had suprarenal inferior vena cava injuries. All 4 underwent repair and 2 survived. Seven others had infrarenal vena cava injuries. Three of 5 survived following repair and the other 2 survived after caval ligation. Three patients had iliac vein injuries. Two died after repair and 1 survived with ligation. Seventeen patients had injuries of the femoral vein. Thirteen underwent repair, 7 of whom remain...
A Monograph on the classification of the discrete subgroups of SU(4)

We here present, in modern notation, the classification of the discrete finite subgroups of SU(4) as well as the character tables for the exceptional cases thereof (cf. http://pierre.mit.edu/~yhe/su4.ct). We hope this catalogue will be useful to works on string orbifold theories, quiver theories, WZW modular invariants, Gorenstein resolutions, nonlinear sigma-models as well as some recently proposed inter-connections among them.
Private Global Business Regulation

Regulations that govern the social and environmental impacts of global firms and markets without state enforcement are a relatively new dimension of global business regulation. The growth of such voluntary “civil regulations” reflects both the expansion of legitimate authority in the global economy outside the state and the increasing use of alternative regulatory instruments to govern firms, including self-regulation, market-based instruments, and soft laws. In response to global social activism, many firms have adopted voluntary regulatory standards to avoid additional regulation and/or to protect their reputations and brands. Activists have targeted highly visible firms and have been willing to work cooperatively with them. The most important civil regulations are multi-stockholder codes, whose governance is shared by firms and nongovernmental organizations (NGOs), and which rely on product and producer certifications. Such codes face the challenge of acquiring legitimacy and of persuading both firms a...
MH-TRACE: multihop time reservation using adaptive control for energy efficiency

In this paper, we propose multihop time reservation using adaptive control for energy efficiency (MH-TRACE), which is a medium access control (MAC) protocol that combines advantageous features of fully centralized and fully distributed networks for energy-efficient real-time packet broadcasting in a multihop radio network. We introduce a novel clustering algorithm that dynamically organizes the network into two-hop clusters. MH-TRACE clusters are just for coordinating channel access and minimizing interference; thus, ordinary nodes are not static members of any cluster. Time is organized into cyclic superframes, which consist of several time frames, to support reservation-based periodic channel access for real-time traffic. Each clusterhead chooses the frame with least interference based on its own measurements for the operation of its cluster. Energy dissipation for receiving unwanted or collided data packets or for waiting in idle mode is avoided through the use of information summarization packets sent prior to the data transmissions by the source nodes. Through the use of transmission schedules within each cluster, managed by the clusterheads, intracluster data collisions are completely eliminated and intercluster collisions are minimized. We investigated MH-TRACE through extensive simulations and theoretical analysis. Our results show that MH-TRACE outperforms existing distributed MAC protocols like IEEE 802.11 and sensor MAC, in terms of energy efficiency and throughput, approaching the theoretical maximum throughput and theoretical minimum energy dissipation.
Strategies for Control of the Space Shuttle Transition

The space shuttle will re-enter the Earth's atmosphere at high angle of attack, in order to minimize total heat load, and will perform a transition to low angle of attack for increased trajectory control. The timing and shaping of this angle transition are affected by specific-control-moment boundaries, attitude instability, angle of attack, limits on various flight parameters, and the establishment of a trimmed condition for flight to the landing site. Transitions to altitudes between 45,000 and 150,000 ft are investigated here, with particular attention given to suitable terminal conditions and to stability and control boundaries. Angle of attack is the control variable; hence, the short-period dynamics are not modeled. Two degree-of-freedom trajectories are optimized using a steepest descent algorithm with automatic step-sizing and open end-time. It is found that trim-glide flight-path angle y becomes very steep as altitude increases and that trajectories to such flight conditions are difficult to achieve. High-altitude equilibrium conditions (y = 0) at zero y are readily obtained, and they provide suitable way points for a continued glide to low altitude. Dynamic pressure and load factor peaks associated with both types of transition are not excessive. Stability and control boundaries have significant effects on the trajectories, although peak load, dynamic pressure and load factor are not materially altered. Gliding trajectories from high to low altitude are found to be sensitive to phugoid mode excitation, and the dynamic pressure peak which occurs prior to the terminal flight condition may be excessive.
Attraction-repulsion transition in the interaction of adatoms and vacancies in graphene

The interaction of two resonant impurities in graphene has been predicted to have a long-range character with weaker repulsion when the two adatoms reside on the same sublattice and stronger attraction when they are on different sublattices. We reveal that this attraction results from a single energy level. This opens up a possibility of controlling the sign of the impurity interaction via the adjustment of the chemical potential. For many randomly distributed impurities (adatoms or vacancies) this may offer a way to achieve a controlled transition from aggregation to dispersion.
Hardware-Friendly Descreening

Conventional electrophotographic printers tend to produce Moire? artifacts when used for printing images scanned from printed material such as books and magazines. We propose a novel noniterative, nonlinear, and space-variant descreening filter that removes a wide range of Moire?-causing screen frequencies in a scanned document while preserving image sharpness and edge detail. This filter is inspired by Perona-Malik's anisotropic diffusion equation. The amount of diffusion of the image intensity resulting from applying the filter is governed by an edge intensity estimate that is robust under halftone noise. More precisely, the filter extracts a spatial feature vector comprising local intensity gradients estimated from a local window in a presmoothed version of the noisy input image. Tunable nonlinear polynomial functions of this feature vector are then used to perform one iteration of a discrete diffusion controlled by the intensity gradient. The polynomial functions and feature extraction kernels are selected empirically in order to minimize computation while ensuring robust performance across a wide range of test images on a target imaging platform. The algorithm uses integer arithmetic, mostly relying on low-cost bit-wise shift and addition operations, and uses a strictly sequential architecture to provide a cost-effective and robust descreening solution in practical imaging devices including copiers and multifunction printers. We compare the performance of the proposed algorithm to other descreening solutions and demonstrate that the new algorithm improves quality over the existing methods while reducing computation.
A time-domain approach to model validation

In this paper we offer a novel approach to control-oriented model validation problems. The problem is to decide whether a postulated nominal model with bounded uncertainty is consistent with measured input-output data. Our approach directly uses time-domain input-output data to validate uncertainty models. The algorithms we develop are computationally tractable and reduce to (generally nondifferentiable) convex feasibility problems or to linear programming problems. In special cases, we give analytical solutions to these problems. >
An unsplit, cell-centered Godunov method for ideal MHD

We present a second-order Godunov algorithm for multidimensional, ideal MHD. Our algorithm is based on the unsplit formulation of Colella (J. Comput. Phys. 87, 1990), with all of the primary dependent variables centered at the same location. To properly represent the divergence-free condition of the magnetic fields, we apply a discrete projection to the intermediate values of the field at cell faces, and apply a filter to the primary dependent variables at the end of each time step. We test the method against a suite of linear and nonlinear tests to ascertain accuracy and stability of the scheme under a variety of conditions. The test suite includes rotated planar linear waves, MHD shock tube problems, low-beta flux tubes, and a magnetized rotor problem. For all of these cases, we observe that the algorithm is second-order accurate for smooth solutions, converges to the correct weak solution for problems involving shocks, and exhibits no evidence of instability or loss of accuracy due to the possible presence of non-solenoidal fields.
New results in NPID control: Tracking, integral control, friction compensation and experimental results

Nonlinear proportional-integral-derivative (NPID) control is implemented by varying the controller gains as a function of system state. NPID control has been previously described and implemented, and recently a constructive Lyapunov stability proof has been given. Here, NPID control analysis and design methods are extended to tracking, and to systems with state feedback and integral control. Experimental results are presented showing improved tracking accuracy and friction compensation by NPID control.
Animal models in epilepsy research: legacies and new directions.

In this Perspective article, Brian Grone and Scott Baraban examine some of the numerous nonhuman animal models of epilepsy. The authors outline how traditional animal models have advanced our understanding of seizure initiation and epileptogenesis and also describe how the use of more 'non-traditional' model systems may further improve insight into both disease mechanisms as well as potential therapeutic avenues. Human epilepsies encompass a wide variety of clinical, behavioral and electrical manifestations. Correspondingly, studies of this disease in nonhuman animals have brought forward an equally wide array of animal models; that is, species and acute or chronic seizure induction protocols. Epilepsy research has a long history of comparative anatomical and physiological studies on a range of mostly mammalian species. Nonetheless, a relatively limited number of rodent models have emerged as the primary choices for most investigations. In many cases, these animal models are selected on the basis of convenience or tradition, although technical or experimental rationale does, and should, factor into these decisions. More complex mammalian brains and genetic model organisms including zebrafish have been studied less, but offer substantial advantages that are becoming widely recognized.
Sporulenes, heptaprenyl metabolites from Bacillus subtilis spores.

Sporulene, a C35-terpenoid hydrocarbon with an unusual pentacyclic structure, is produced by Bacillus subtilis during sporulation.
Imaging bright-spots in the accretion flow near the black hole horizon of Sgr A*

Images from the vicinity of the black hole horizon at the Galactic centre (Sgr A*) could be obtained in the near future with a Very Large Baseline Array of submillimetre telescopes. The recently observed short-term infrared and X-ray variability of the emission from Sgr A* implies that the accretion flow near the black hole is clumpy or unsteady. We calculate the appearance of a compact emission region (bright-spot) in a circular orbit around a spinning black hole as a function of orbital radius and orientation. We find that the mass and spin of the black hole can be extracted from their generic signatures on the spot image as well as on the light curves of its observed flux and polarization. The strong field distortion remains notable even when the spot image is smoothed over the expected ∼20-μ as resolution of the future submillimetre observations.
Acute Effects of Nicotine on Risky Choice among Non-Smokers

Research examining the relationship between acute nicotine use and experimental measures of risk-taking has yielded conflicting results. The present study sought to expand upon research investigating the acute impact of nicotine on risky choice among non-smokers while measuring and controlling for gender, a potentially confounding variable. Utilizing a between-group, double-blind, experimental design, 69 participants were randomly assigned to one of three conditions (placebo, 2 mg, or 4 mg nicotine gum). Participants completed two behavioral risk-taking measures and a motor control task. Individuals in the nicotine conditions demonstrated a main effect of decreased risk-taking on one measure. An interaction between nicotine, gender and risk-taking was found on the second measure of risk-taking, with only males showing decreased risk-taking in higher nicotine conditions. Results suggest nicotine has an acute effect on non-smokers’ patterns of risk-taking, and provide direction for further research on differential effects of nicotine on risk-taking tasks.
New developments in the remote estimation of the fraction of absorbed photosynthetically active radiation in crops

[1] The fraction of absorbed photosynthetically active radiation, fAPAR, is an important biophysical characteristic in models of gas exchange between the terrestrial boundary layer and the atmosphere, as well as in the analysis of vegetation productivity. Synoptic estimation of fAPAR has been performed by using NDVI as a linear proxy of fAPAR, despite the saturation of NDVI at fAPAR beyond 0.7. This paper analyzes the NDVI/fAPAR relationship in row crops (i.e. maize and soybean), and evaluates alternative vegetation indices to overcome the loss of sensitivity of NDVI at moderate-to-high vegetation biomass. Red-edge NDVI, which uses NIR and a band around 700 nm and the recently proposed Wide Dynamic Range Vegetation Index, which uses red and NIR bands only, were found to be sensitive to fAPAR variation along its entire range and exhibited significant increase in sensitivity to fAPAR.