cssi/SciSciGPT-SciSciNet huggingface dataset:
Robust quantization for digital finite communication bandwidth (DFCB) control

The problem of digital finite communication bandwidth (DFCB) control has come to the attention of the research community in connection with a growing interest in the development of distributed and/or networked control systems. In these systems, actuators, sensors, and other components are connected via data-rate constrained links such as wireless radio, etc. In this paper, we consider a scalar model of DFCB control that accommodates time-varying data-rate constraints, such as might occur with intermittent network congestion, and asynchronism of sampling and control actuation. Because of the possibly unpredictable fluctuation of the data-rate, we are interested in feedback control designs that will tolerate significantly constrained data-rates on feedback loops, while providing acceptable performance when such data-rate constraints are not in force. In light of a very basic notion of acceptable performance, we show that control designs with different number of quantization levels tolerate constrained data-rates differently. This leads to the conclusion that binary control represents the most robust control quantization under data-rate constraints imposed by time-varying congestion on the feedback communication channel. The advantage margin of binary control is further investigated numerically with and without the sampling-control asynchronism being considered. We show that the advantage margin is more substantial when the sampling-control asynchronism is significant. A design of quantized (binary) feedback with side channel information is proposed, and stability properties are discussed. We conclude the paper by examining performance limitations of our binary coding in the presence of noise.
Coupling between Structure and Liquid Propellants in a Parallel- Stage Space Shuttle Design

A study was conducted to determine the influence of liquid propellants on the dynamic loads for space shuttle vehicles. A parallel-stage configuration model was designed and tested to determine the influence of liquid propellants on coupled natural modes. A forty degree-of-freedom analytical model was also developed for predicting these modes. Currently available analytical models were used to represent the liquid contributions, even though coupled longitudinal and lateral motions are present in such a complex structure. Agreement between the results was found in the lower few modes.
Order Effects in Complex and Simple Tasks

There is strong evidence that the order in which response options are presented in surveys significantly affects the answers that respondents provide. According to the theory of survey satisficing, the severity of order effects should increase with task difficulty. However, the tasks provided to respondents in existing studies of response-order effects are generally very simple, making it difficult to evaluate the satis- ficing hypothesis. Further, evidence from cognitive psychology suggests a completely different mechanism: people are more motivated to persist in completing tasks when they are intricate, challenging, and enriching. I designed survey experiments administered over the Internet consisting of two types of tasks: (1) a complex task in which respondents were asked to rank seven public officials in order of how much they should be blamed for the property damage and loss of life caused by Hurricane Katrina in the city of New Orleans; and (2) a series of simple tasks in which respon- dents answered items with ordinal response choices on rating scales. I found almost no order effects in the complex task among all educational groups. Conversely, I found significant and substantial order effects in the simple tasks, particularly among low-education respondents. These results suggest that theories of survey satisficing may simplify matters by assuming that satisficing monotonically increases with task difficulty. Moreover, my findings have important implications for questionnaire design, underscoring the importance of randomizing response options.
Revealing uncertainty for information visualization

Uncertainty in data occurs in domains ranging from natural science to medicine to computer science. By developing ways to include uncertainty in our information visualizations, we can provide more accurate depictions of critical data sets so that people can make more infc.rmed decisions.One hindrance to visualizing uncertainty is that we must first understand what uncertainty is and how it is expressed. We reviewed existing work from several domains on uncertainty and created a classification of uncertainty based on the literature. We empirically evaluated and improved upon our classification by conducting interviews with 18 people from several domains,who self-identified as working with uncertainty. Participants desuibed what uncertainty looks like in their data and how they deal with it. We found commonalities in uncertainty across domains and believe our refined classification will help us in developing appropriate visualizations for each category of uncertainty.
Oxidation of phenol in acidic aqueous suspensions of manganese oxides

Phenol (benzenol) oxidation by three synthetic manganese oxides (buserite, manganite, and feitknechtite) has been studied in aerated, aqueous, acidified suspensions. The rate of reaction was pH dependent. Oxidation was greatly enhanced below pH 4, when diphenoquinone and p-benzoquinone were identified as the first products. Initial reaction rate was correlated with standard reduction potential (E ~ of the oxides following the order: feitknechtite > manganite > buserite. A more gradual process of phenol oxidation after the initial reaction was influenced by electrochemical properties of the solution. High soluble manganese activity and increase in pH adversely affected reaction rates. Thus, the reactivity of the oxides was related to their stability and possibly the ability to readsorb Mn(II), following the order: buserite > manganite > feitknechtite. The results indicate that thermodynamic and electrochemical data for oxides and phenols are useful in predicting under which conditions phenols can be oxidized by a given system.
Pd-Pt Bimetallic Nanodendrites with High Activity for Oxygen Reduction

Controlling the morphology of Pt nanostructures can provide a great opportunity to improve their catalytic properties and increase their activity on a mass basis. We synthesized Pd-Pt bimetallic nanodendrites consisting of a dense array of Pt branches on a Pd core by reducing K2PtCl4 with L-ascorbic acid in the presence of uniform Pd nanocrystal seeds in an aqueous solution. The Pt branches supported on faceted Pd nanocrystals exhibited relatively large surface areas and particularly active facets toward the oxygen reduction reaction (ORR), the rate-determining step in a proton-exchange membrane fuel cell. The Pd-Pt nanodendrites were two and a half times more active on the basis of equivalent Pt mass for the ORR than the state-of-the-art Pt/C catalyst and five times more active than the first-generation supportless Pt-black catalyst.
Shocks, Commitment, and the Risk of Civil War

This article investigates how shocks to state capabilities are related to the probability of civil war. Drawing on Powell (2004, 2006), shocks are conceptualized as shifts in the domestic distribution of power that can lead to bargaining breakdown and, consequently, violent conflict. Following a shock to the state's capabilities, the leadership has incentives to grant concessions to other groups within the state, yet such promises are not credible given that the leadership may regain its strength. Similarly, opposition groups cannot make credible commitments as they expect to be more powerful in the future. Unable to commit, both actors may use force to achieve their preferred outcome. The study then analyzes how the institutional structure of the state's leadership and opposition groups influences actors' credibility during this bargaining process. Statistical analysis of all leaders for the 1960–2004 time period shows that shocks such as economic recession, war defeat, and changes in the international b...
Multiscale Dictionary Learning for Estimating Conditional Distributions

Nonparametric estimation of the conditional distribution of a response given high-dimensional features is a challenging problem. It is important to allow not only the mean but also the variance and shape of the response density to change flexibly with features, which are massive-dimensional. We propose a multiscale dictionary learning model, which expresses the conditional response density as a convex combination of dictionary densities, with the densities used and their weights dependent on the path through a tree decomposition of the feature space. A fast graph partitioning algorithm is applied to obtain the tree decomposition, with Bayesian methods then used to adaptively prune and average over different sub-trees in a soft probabilistic manner. The algorithm scales efficiently to approximately one million features. State of the art predictive performance is demonstrated for toy examples and two neuroscience applications including up to a million features.
A Short Synthesis of 1-Vinyluracil and 1-Vinylthymine

Abstract 1-Vinyluracil and 1-vinylthymine, monomers for nucleic acid bases attached functional polymers, were synthesized for the first time from uracil and thymine in 3 steps in 54% and 50% overall yields using the Mitsunobu reactions of 2a and 2b with 2-chloroethanol as a key step.
An Experimental Study of the Effects of Liquid Properties on the Breakup of a Two-Dimensional Liquid Sheet

Author(s): Stapper, BE; Sowa, WA; Samuelsen, GS | Abstract: The breakup of a liquid sheet is of fundamental interest in the atomization of liquid fuels. The present study explores the breakup of a two-dimensional liquid sheet in the presence of co-flow air with emphasis on the extent to which liquid properties affect breakup. Three liquids, selected with varying values of viscosity and surface tension, are introduced through a twin-fluid, two-dimensional nozzle. A pulsed laser imaging system is used to determine the sheet structureat breakup, the distance and time to breakup, and the character of the ligaments and droplets formed. Experiments are conducted at two liquid flow rates with fiveflow rates of co-flowing air. Liquid properties affect the residence time required to initiate sheet breakup, and alter the time and length scales in the breakup mechanism. © 1992 ASME.
Simultaneous Shield and Buffer Insertion for Crosstalk Noise Reduction in Global Routing

As VLSI technologies scale down, interconnect performance is greatly affected by crosstalk noise due to the decreasing wire separation and increased wire aspect ratio, and crosstalk has become a major bottleneck for design closure. The effectiveness of traditional buffering and spacing techniques for noise reduction is constrained by the limited available resources on chip. In this paper, we present a method for incorporating crosstalk reduction criteria into global routing under a broad power supply network paradigm. This method utilizes power/ground wires as shields between signal wires to reduce capacitive coupling, while considering the constraints imposed by limited routing and buffering resources. An iterative procedure is employed to route signal wires, assign supply shields, and insert buffers so that both buffer/routing capacity and signal integrity goals are met. In each iteration, shield assignment and buffer insertion are considered simultaneously via a dynamic programming-like approach. Our noise calculations are based on Devgan's metric, and our work demonstrates, for the first time, that this metric shows good fidelity on average. An effective noise margin inflation technique is also proposed to compensate for the pessimism of Devgan's metric. Experimental results on testcases with up to about 10000 nets point towards an asymptotic runtime that increases linearly with the number of nets. Our algorithm achieves noise reduction improvements of up to 53% and 28%, respectively, compared to methods considering only buffer insertion or only shield insertion after buffer planning.
Squirt flow in fully saturated rocks

We estimate velocity/frequency dispersion and attenuation in fully saturated rocks by employing the squirt‐flow mechanism of solid/fluid interaction. In this model, pore fluid is squeezed from thin soft cracks into the surrounding large pores. Information about the compliance of these soft cracks at low confining pressures is extracted from high‐pressure velocity data. The frequency dependence of squirt‐induced pressure in the soft cracks is linked with the porosity and permeability of the soft pore space, and the characteristic squirt‐flow length. These unknown parameters are combined into one expression that is assumed to be a fundamental rock property that does not depend on frequency. The appropriate value of this expression for a given rock can be found by matching our theoretical predictions with the experimental measurements of attenuation or velocity. The low‐frequency velocity limits, as given by our model, are identical to those predicted by Gassmann’s formula. The high‐frequency limits may sign...
Strategic Responses to Bank Regulation: Evidence From HMDA Data

The intent of fair lending regulation is to encourage loans in low-income areas and ensure that loan decisions are based on economic criteria instead of noneconomic borrower characteristics. We evaluate situations in which banks may find it in their self interest to respond to regulation in a strategic manner intended to improve public relations and appease regulators rather than to adhere to the true spirit of the regulation. We find some evidence consistent with such behavior.
An adaptive hysteresis-band current control technique of a voltage-fed PWM inverter for machine drive system

An adaptive hysteresis-band control method where the band is modulated with the system parameters to maintain the modulation frequency to be nearly constant is described. Although the technique is applicable to general AC motor drives and other types of load, an interior permanent magnet (IPM) synchronous machine load is considered. Systematic analytical expressions of the hysteresis band are derived as functions of system parameters. An IPM machine drive system with a voltage-fed current-controlled PWM (pulse width modulation) inverter has been computer simulated to study the performance of the proposed method. >
Do Social-Welfare Policies Reduce Poverty? A Cross-National Assessment

Most social scientists, policymakers, and citizens who support the welfare state do so in part because they believe social-welfare programs help to reduce the incidence of poverty. Yet a growing number of critics assert that such programs in fact fail to decrease poverty, because too small a share of transfers actually reaches the poor, or because such programs create a welfare/poverty trap, or because they weaken the economy. This study assesses the effects of social-welfare policy extensiveness on poverty rates across fifteen affluent industrialized nations over the period 1960-91, using both absolute and relative measures of poverty. The results strongly support the conventional view that social-welfare programs reduce poverty
Analytic study of the effective parameters for determination of the NMO velocity function in transversely isotropic media

In their studies of transversely isotropic media with a vertical symmetry axis (VTI media), Alkhalifah and Tsvankin observed that, to a high numerical accuracy, the normal moveout (NMO) velocity for dipping reflectors as a function of ray parameter p depends mainly on just two parameters, each of which can be determined from surface P‐wave observations. They substantiated this result by using the weak‐anisotropy approximation and exploited it to develop a time‐domain processing sequence that takes into account vertical transverse isotropy. In this study, the two‐parameter Alkhalifah‐Tsvankin result was further examined analytically. It was found that although there is (as these authors already observed) some dependence on the remaining parameters of the problem, this dependence is weak, especially in the practically important regimes of weak to moderately strong transverse isotropy and small ray parameter. In each of these regimes, an analytic solution is derived for the anisotropy parameter η required fo...
Structure, behavior, and market power in an evolutionary labor market with adaptive search☆

Abstract This study uses an agent-based computational labor market framework to experimentally study the relationship between job capacity, job concentration, and market power. Job capacity is measured by the ratio of potential job openings to potential work offers, and job concentration is measured by the ratio of work suppliers to employers. For each experimental treatment, work suppliers and employers repeatedly seek preferred worksite partners based on continually updated expected utility, engage in efficiency-wage worksite interactions modelled as prisoner's dilemma games, and evolve their worksite behaviors over time. The main finding is that job capacity consistently trumps job concentration when it comes to predicting the relative ability of work suppliers and employers to exercise market power.
Septal myectomy for obstructive hypertrophic cardiomyopathy

Septal myectomy effectively relieves left ventricular outflow tract obstruction (LVOTO) and cardiac symptoms in both adults and children with obstructive hypertrophic cardiomyopathy (HCM). Abnormal attachments of the papillary muscles and chordae and other cardiac lesions can be repaired at the same time. Early mortality for isolated septal myectomy in both children and adults is low (0% to 2.5%). Median echocardiographic LVOT gradients at rest on late follow-up have been as low as 0 to 5 mm Hg. Symptomatic improvements after myectomy occurs in the majority; 90% of patients improve by at least one functional class, and most remain improved on late follow-up. Late survivorship compares very favorably with the natural history of nonoperated patients with symptomatic obstructive HCM. These results serve as a basis for comparison with newer nonsurgical alternatives.
Characterization of traffic oscillation propagation under nonlinear car-following laws

Unlike linear car-following models, nonlinear models generally can generate more realistic traffic oscillation phenomenon, but nonlinearity makes analytical quantification of oscillation characteristics (e.g, periodicity and amplitude) significantly more difficult. This paper proposes a novel mathematical framework that accurately quantifies oscillation characteristics for a general class of nonlinear car-following laws. This framework builds on the describing function technique from nonlinear control theory and is comprised of three modules: expression of car-following models in terms of oscillation components, analyses of local and asymptotic stabilities, and quantification of oscillation propagation characteristics. Numerical experiments with a range of well-known nonlinear car-following laws show that the proposed approach is capable of accurately predicting oscillation characteristics under realistic physical constraints and complex driving behaviors. This framework not only helps further understand the root causes of the traffic oscillation phenomenon but also paves a solid foundation for the design and calibration of realistic nonlinear car-following models that can reproduce empirical oscillation characteristics.
Building virtual worlds for informal science learning (SciCentr and SciFair) in the active worlds educational universe (AWEDU)

As a focus of its exploration of desktop 3-D environments for science outreach, the Cornell Theory Center (CTC), Cornell University's high-performance computing center, has been exploring the use of the Active Worlds client/server technology for implementation of a 3-D multiuser virtual science museum. SciCentr, that incorporates interactive simulation-based exhibits. We present here early lessons in accommodating the needs of several interconnected user groups as we move forward with establishing the SciCentr community within the greater educational community of Active Worlds Educational Universe (AWEDU) and the Contact Consortium's VLearn3D initiative. We learned that we must provide the user communities with both social and spatial frameworks within which to work and play. Social Support ranges from one-on-one, over-the-shoulder help, to guidance and training within the environment, to coordination of "inworld" activities and in-person pizza parties. Spatial design requirements depend on the activities of the user group and benefit from study of real and virtual world examples. Our experience to date with a pilot group of teenaged participants is encouraging, and we believe that this medium has potential as a resource for constructivist informal science and technology education.
Synthetic Routes to Methylerythritol Phosphate Pathway Intermediates and Downstream Isoprenoids

Isoprenoids constitute the largest class of natural products with greater than 55,000 identified members. They play essential roles in maintaining proper cellular function leading to maintenance of human health, plant defense mechanisms against predators, and are often exploited for their beneficial properties in the pharmaceutical and nutraceutical industries. Most impressively, all known isopre- noids are derived from one of two C5-precursors, isopentenyl diphosphate (IPP) or dimethylallyl diphosphate (DMAPP). In order to study the enzyme transformations leading to the extensive structural diversity found within this class of compounds there must be access to the substrates. Sometimes, intermediates within a biological pathway can be isolated and used directly to study enzyme/pathway function. However, the primary route to most of the isoprenoid intermediates is through chemical catalysis. As such, this review provides the first exhaustive examination of synthetic routes to isoprenoid and isoprenoid precursors with particular emphasis on the syntheses of interme- diates found as part of the 2C-methylerythritol 4-phosphate (MEP) pathway. In addition, representative syntheses are presented for the monoterpenes (C10), sesquiterpenes (C15), diterpenes (C20), triterpenes (C30) and tetraterpenes (C40). Finally, in some instances, the syn- thetic routes to substrate analogs found both within the MEP pathway and downstream isoprenoids are examined.
Resource reallocation and innovation : converting enterprise risks into opportunities

This paper argues that the increased flow and management of knowledge permitted by knowledge-based capital, supported by appropriate policies, can be an important factor in reducing the decision risk facing enterprises due to uncertainty and imperfect information, helping improve the resilience of development outcomes. Enterprises are conceptualized as information platforms that manage risk through investments in knowledge-based capital and complementary assets, providing them with the knowledge, protection/enabling, insurance, and coping/leveraging abilities to make better decisions in response to shocks. Investments in knowledge-based capital allow enterprises to better convert voluntary but risky reallocation and innovation decisions into productivity and wealth-enhancing opportunities. They can help the enterprise sector as a whole and most people to self-protect and realize better jobs, earnings, and consumption outcomes by adapting to shocks. However, absent appropriate policies, knowledge-based capital can have adverse distributional effects -- including a skewed industrial concentration of productivity gains and more unequal consumption and income-earning outcomes between rich and poor people. The paper discusses the role of policy in facilitating risk management by enterprises, ultimately to reduce poverty and boost shared prosperity. Insufficient enterprise risk-taking is costly for the enterprise sector and the economy as it results in too little experimentation and learning. The paper argues that governments should create business environments that stimulate entrepreneurial risk-taking to invest in market and social opportunities that combine new technologies with appropriately-skilled workers. Policies allowing people to better confront and manage their risks include: (1) spurring entrepreneurial experimentation; (2) supporting skills upgrading; and (3) promoting mechanisms for joint learning through global collaboration.
N-tert-butanesulfinyl imines: versatile intermediates for the asymmetric synthesis of amines.

N-tert-Butanesulfinyl aldimines 3 and ketimines 4 are exceedingly versatile intermediates for the asymmetric synthesis of amines. The N-tert-butanesulfinyl imines are prepared in high yields by condensing enantiomerically pure tert-butanesulfinamide 1, which is readily available in either configuration, with a wide range of aldehydes and ketones. The tert-butanesulfinyl group activates the imines for the addition of many different classes of nucleophiles, serves as a powerful chiral directing group, and after nucleophilic addition is readily cleaved by treatment of the product with acid. A wide range of highly enantioenriched amines, including α-branched and α,α-dibranched amines, α- and β-amino acids, 1,2- and 1,3-amino alcohols, and α-trifluoromethyl amines, are efficiently synthesized using this methodology. In addition, N-tert-butanesulfinyl imine derivatives provide a new family of ligands for asymmetric catalysis.
Effects of device aging on microelectronics radiation response and reliability

Abstract We review recent work that shows that, for several kinds of devices built by several different manufacturers, MOS and bipolar device radiation response can change significantly with pre-irradiation elevated temperature stress and/or with aging time after device fabrication or packaging. The primary effects that have been observed are related to changes in interface-trap charge buildup, but some effects are also noted for charge trapped in the oxide. On the basis of a wide array of experimental data and first-principles calculations, these changes are attributed to the motion and reactions of hydrogenous species, e.g., protons and water. Similar reactions with hydrogen can also affect the reliability of MOS devices and integrated circuits, as illustrated here for the case of negative bias-temperature instability for high-κ alternative gate dielectrics. Heating the device accelerates some kinds of aging effects, but reverses the effects of others. These observations are consistent with a dual role for hydrogen in improving or degrading device performance, depending on its particular incorporation in the device and subsequent motion and reactions. These results emphasize that measurements used to provide estimates of MOS radiation response and long-term reliability can vary significantly with time. In some cases, typical margins built into radiation response and reliability tests may be inadequate to account for aging-related changes in device performance.
Does observation influence learning

Abstract A common value auction experiment is run to compare the relative influence of observation and experience on learning. It is shown that the ex-post observation of opponents' actions and payoffs homogenizes behavior and accelerates learning toward the Nash equilibrium. Additionally, experiential, and observational learning are both relevant and of comparable magnitude. A general reinforcement model for continuous strategies, encompassing choice reinforcement learning, direction learning and payoff dependent imitation, performs well in explaining the experimental data, and it dominates competing models such as the reinforcement of best response strategies.
Wide Area Computation

The last decades have seen the emergence of the sea of objects paradigm for structuring complex distributed systems on workstations and local area networks. In this approach, applications and system services are composed of and communicate among themselves through reliable and transparently accessible object interfaces, leading to the interaction of hundred or thousands of unstructured objects. This approach has lead to major progress in software composability and reliability. Unfortunately, it is based on a number of assumptions that do not hold on wide area networks. There, access to resources is intrinsically unreliable (because of failure, congestion, voluntary disconnected operation, etc.) and not transparent (because of variations in latency and bandwidth, hardware and software mobility, and the presence of firewalls). These characteristics are so radically different from the current computational norm that they amount to a new model of computation. We discuss the challenges of computation on wide area networks. Our approach reflects the intuition that, to function satisfactorily on a wide area network, the sea of objects must be partitioned and made hierarchical, internally mobile, and secure. This paper is an abridged version of [3].
The nature and development of steroid hormone receptors.

Our current conceptualization of the primary steps in steroid hormone (estrogens, androgens, progestins and corticoids) action is shown in figure l10. We now believe that the steroids, which are generally hydrophobic molecules, diffuse through the outer cell membrane and cytoplasm to the nucleus47. In the nucleus the steroids bind to their respective receptors which are assumed to be bound with low affinity to some nuclear component35. This nuclear component could be DNA, nuclear matrix or some chromatin protein (acceptor) but this has not been proven conclusively. As a result of the steroid-receptor interaction, the receptor’s conformation changes dramatically and its affinity for nuclear components becomes much higher1113,51. This change in the association of receptor with nuclear components is correlated with, and may lead to the rapid (within minutes) changes in gene expression observed in the target tissues1,25,29. This general model may apply to all the steroid hormones, vitamin D metabolites and thyroxine, but has not been clearly demonstrated for all such hormones.
Layered tetrahedral meshing of thin-walled solids for plastic injection molding FEM

This paper describes a method for creating a well-shaped, layered tetrahedral mesh of a thin-walled solid by adapting the surface triangle sizes to the estimated wall thickness. The primary target application of the method is the finite element analysis of plastic injection molding, in which a layered mesh improves the accuracy of the solution. The edge lengths of the surface triangles must be proportional to the thickness of the domain to create well-shaped tetrahedrons; when the edge lengths are too short or too long, the shape of the tetrahedron tends to become thin or flat. The proposed method creates such a layered tetrahedral mesh in three steps: (1) create a preliminary tetrahedral mesh of the target geometric domain and estimate thickness distribution over the domain; (2) create a non-uniform surface triangular mesh with edge length adapted to the estimated thickness, then create a single-layer tetrahedral mesh using the surface triangular mesh; and (3) subdivide tetrahedrons of the single-layer mesh into multiple layers by applying a subdivision template. The effectiveness of the layered tetrahedral mesh is verified by running some experimental finite element analyses of plastic injection molding.
Performance of Magnetic Quantum Cellular Automata and Limitations Due to Thermal Noise

Operation parameters of magnetic quantum cellular automata are evaluated for the purposes of reliable logic operation. The dynamics of the nanomagnets is simulated via the Landau-Lifshitz-Gilbert equations with a stochastic magnetic field corresponding to thermal fluctuations. It is found that in the macrospin approximation, the switching speed does not change under scaling of both size and distances between nanomagnets. Thermal fluctuations put a limitation on the size of nanomagnets: when we consider a majority gate that features a biaxial anisotropy as a stabilizing mechanism and a uniform clocking field, the gate error rate becomes excessive for nanomagnets smaller than about 200 nm at room temperature.
PresenceSense: zero-training algorithm for individual presence detection based on power monitoring

Non-intrusive presence detection of individuals in commercial buildings is much easier to implement than intrusive methods such as passive infrared, acoustic sensors, and camera. Individual power consumption, while providing useful feedback and motivation for energy saving, can be used as a valuable source for presence detection. We conduct pilot experiments in an office setting to collect individual presence data by ultrasonic sensors, acceleration sensors, and WiFi access points, in addition to the individual power monitoring data. PresenceSense (PS), a semi-supervised learning algorithm based on power measurement that trains itself with only unlabeled data, is proposed, analyzed and evaluated in the study. Without any labeling efforts, which are usually tedious and time consuming, PresenceSense outperforms popular models whose parameters are optimized over a large training set. The results are interpreted and potential applications of PresenceSense on other data sources are discussed. The significance of this study attaches to space security, occupancy behavior modeling, and energy saving of plug loads.
Simple evolution of complex crystal species

Cairns-Smith has proposed that life began as structural patterns in clays that self-replicated during cycles of crystal growth and fragmentation. Complex, evolved crystal forms could then have catalyzed the formation of a more advanced genetic material. A crucial weakness of this theory is that it is unclear how complex crystals might arise through Darwinian evolution and selection. Here we investigate whether complex crystal patterns could evolve using a model system for crystal growth, DNA tile crystals, that is amenable to both theoretical and experimental inquiry. It was previously shown that in principle, the evolution of crystals assembled from a set of thousands of DNA tile types under very specific environmental conditions could produce arbitrarily complex patterns. Here we show that evolution driven only by the dearth of one monomer type could produce complex crystals from just 12 monomer types. When a monomer type is rare, crystals that use few of this monomer type are selected for. We use explicit enumeration to show that there are situations in which crystal species that use a particular monomer type less frequently will grow faster, yet to do so requires that the information contained in the crystal become more complex. We show that this feature of crystal organization could allow more complex crystal morphologies to be selected for in the right environment, using both analysis in a simple model of self-assembly and stochastic kinetic simulations of crystal growth. The proposed mechanism of evolution is simple enough to test experimentally and is sufficiently general that it may apply to other DNA tile crystals or even to natural crystals, suggesting that complex crystals could evolve from simple starting materials because of relative differences in concentrations of the materials needed for growth.
Structure and Absolute Stereochemistry of Phormidolide, a New Toxic Metabolite from the Marine Cyanobacterium Phormidium sp.

The extract from a laboratory culture of an Indonesian isolate of the cyanobacterium Phormidium sp. displayed inhibitory activity in a Ras-Raf protein interaction assay. Assay-guided fractionation led to the isolation of both active and inactive materials of novel structure. The major inactive metabolite, phormidolide, was nevertheless highly toxic to brine shrimp (LC(50) = 1.5 microM), and hence, its structure was elucidated using various spectroscopic methods, primarily NMR. A series of partial structures were developed from standard experiments and then assembled using GHMBC, 2D INADEQUATE, and ACCORD-ADEQUATE data obtained on a (13)C-enriched sample. The relative stereochemistry at phormidolide's 11 chiral centers was established using the J-based configuration analysis method in concert with the G-BIRD(R)-HSQMBC NMR experiment. Absolute stereochemistry was determined on a bis-acetonide derivative using the variable temperature Mosher ester method. The robust number of NMR restraints provided from determination of most homonuclear and heteronuclear coupling constants in phormidolide, along with an abundance of NOE information, allowed construction of a refined lowest energy three-dimensional structure in Macromodel. Phormidolide is one of only a few macrolide-type natural products to be reported from marine cyanobacteria.
Nuclear fluorination of 3,5-diarylisoxazoles with Selectfluor®

C-4 Fluorination of a series of 3,5-diarylisoxazoles has been accomplished using the N-F reagent Selectfluor®. With substrates containing neutral or activating substituents on the 5-phenyl ring, acetonitrile at room temperature or at reflux could be used as solvent. However, when deactivating substituents were present, a higher reaction temperature was required for which sulfolane was found to be a good solvent. At this higher temperature, a unique trifluorination of the isoxazole nucleus by an addition mechanism occurred as a side reaction.
Performance of the monitoring light source for the CMS lead tungstate crystal calorimeter

Light monitoring will play a crucial role in maintaining energy resolution for the CMS lead tungstate crystal calorimeter at LHC. In the last several years, a laser based monitoring light source was designed and constructed at Caltech, and was installed and commissioned at CERN. This paper presents the design of the CMS ECAL monitoring light source and its performance during beam tests. Issues related to the monitoring precision are discussed.
Signatures for network coding

This paper presents a practical digital signature scheme to be used in conjunction with network coding. Furthermore, the authors' idea simultaneously provides authentication and detects malicious nodes that intentionally corrupt content on the network.
Annulation of aromatic imines via directed C-H bond activation

A directed C-H bond activation approach to the synthesis of indans, tetralins, dihydrofurans, dihydroindoles, and other polycyclic aromatic compounds is presented. Cyclization of aromatic ketimines and aldimines containing alkenyl groups tethered at the meta position relative to the imine directing group has been achieved using (PPh3)3RhCl (Wilkinson's catalyst). The cyclization of a range of aromatic ketimines and aldimines provides bi- and tricyclic ring systems with good regioselectivity. Different ring sizes and substitution patterns can be accessed through the coupling of monosubstituted, 1,1- or 1,2-disubstituted, and trisubstituted alkenes bearing both electron-rich and electron-deficient functionality.
Optical Design for Lasers in Surgery

Laser light can be used to cut and cauterize tissue. At the present time CO2 lasers at 10.6 um, argon ion lasers in the blue green part of the spectrum, and Nd:YAG lasers at 1.06 um have operational characteristics which make their use in surgery potentially valuable. In this paper, the optics presently used to deliver the light from these lasers to surgical targets are described. Since there is little optical design information available for existing devices and since a great deal of improvement is possible, most of the discussion is concerned with proposals for achieving improved performance. In addition, a discussion is included of safety precautions for both patients and operating room personnel.
Fighting bandits with a new kind of smoothness

We provide a new analysis framework for the adversarial multi-armed bandit problem. Using the notion of convex smoothing, we define a novel family of algorithms with minimax optimal regret guarantees. First, we show that regularization via the Tsallis entropy, which includes EXP3 as a special case, matches the O(√NT) minimax regret with a smaller constant factor. Second, we show that a wide class of perturbation methods achieve a near-optimal regret as low as O(√NT log N), as long as the perturbation distribution has a bounded hazard function. For example, the Gumbel, Weibull, Frechet, Pareto, and Gamma distributions all satisfy this key property and lead to near-optimal algorithms.
Copper Hydride Catalyzed Hydroamination of Alkenes and Alkynes

Over the past few years, CuH-catalyzed hydroamination has been discovered and developed as a robust and conceptually novel approach for the synthesis of enantioenriched secondary and tertiary amines. The success in this area of research was made possible through the large body of precedent in copper(I) hydride catalysis and the well-explored use of hydroxylamine esters as electrophilic amine sources in related copper-catalyzed processes. This Minireview details the background, advances, and mechanistic investigations in CuH-catalyzed hydroamination.
Numerical kekulé structures of fullerenes and partitioning of π-electrons to pentagonal and hexagonal rings

We calculated the partitioning of π-electrons within individual pentagonal and hexagonal rings of fullerenes for a collection of fullerenes from C20 to C72 by constructing their Kekule valence structures and averaging the π-electron content of individual rings over all Kekule valence structures. The resulting information is collected in Table 2, which when combined with the Schlegel diagram of fullerenes (illustrated in Figure 7) uniquely characterizes each of the 19 fullerenes considered. The results are interpreted as the basic information on the distributions (variation) of the local (ring) π-electron density.
Strong accountability for network storage

This article presents the design, implementation, and evaluation of CATS, a network storage service with strong accountability properties. CATS offers a simple web services interface that allows clients to read and write opaque objects of variable size. This interface is similar to the one offered by existing commercial Internet storage services. CATS extends the functionality of commercial Internet storage services by offering support for strong accountability.A CATS server annotates read and write responses with evidence of correct execution, and offers audit and challenge interfaces that enable clients to verify that the server is faithful. A faulty server cannot conceal its misbehavior, and evidence of misbehavior is independently verifiable by any participant. CATS clients are also accountable for their actions on the service. A client cannot deny its actions, and the server can prove the impact of those actions on the state views it presented to other clients.Experiments with a CATS prototype evaluate the cost of accountability under a range of conditions and expose the primary factors influencing the level of assurance and the performance of a strongly accountable storage server. The results show that strong accountability is practical for network storage systems in settings with strong identity and modest degrees of write-sharing. We discuss how the accountability concepts and techniques used in CATS generalize to other classes of network services.
High-Skilled Immigration and the Rise of STEM Occupations in U.S. Employment

In this paper, we document the importance of high-skilled immigration for U.S. employment in STEM fields. To begin, we review patterns of U.S. employment in STEM occupations among workers with at least a college degree. These patterns mirror the cycle of boom and bust in the U.S. technology industry. Among younger workers, the share of hours worked in STEM jobs peaked around the year 2000, at the height of the dot-com bubble. STEM employment shares are just now approaching these previous highs. Next, we consider the importance of immigrant labor to STEM employment. Immigrants account for a disproportionate share of jobs in STEM occupations, in particular among younger workers and among workers with a master's degree or PhD. Foreign-born presence is most pronounced in computer-related occupations, such as software programming. The majority of foreign-born workers in STEM jobs arrived in the U.S. at age 21 or older. Although we do not know the visa history of these individuals, their age at arrival is consistent with the H-1B visa being an important mode of entry for highly trained STEM workers into the U.S. Finally, we examine wage differences between native and foreign-born labor. Whereas foreign-born workers earn substantially less than native-born workers in non-STEM occupations, the native-foreign born earnings difference in STEM jobs is much smaller. Further, foreign-born workers in STEM fields reach earnings parity with native workers much more quickly than they do in non-STEM fields. In non-STEM jobs, foreign-born workers require 20 years or more in the U.S. to reach earnings parity with natives; in STEM fields, they achieve parity in less than a decade.
QUASI-INDEXICAL REFERENCE IN PROPOSITIONAL SEMANTIC NETWORKS

We discuss how a deductive question-answering system can represent the beliefs or other cognitive states of users, of other (interacting) systems, and of itself. In particular, we examine the representation of first-person beliefs of others (e.g., the system's representation of a user's belief that he himself is rich). Such beliefs have as an essential component "quasi-indexical pronouns" (e.g., 'he himself'), and, hence, require for their analysis a method of representing these pronominal constructions and performing valid inferences with them. The theoretical justification for the approach to be discussed is the representation of nested "de dicto" beliefs (e.g., the system's belief that user-1 believes that system-2 believes that user-2 is rich). We discuss a computer implementation of these representations using the Semantic Network Processing System (SNePS) and an ATN parser-generator with a question-answering capability.
Dynamic ocean management increases the efficiency and efficacy of fisheries management

In response to the inherent dynamic nature of the oceans and continuing difficulty in managing ecosystem impacts of fisheries, interest in the concept of dynamic ocean management, or real-time management of ocean resources, has accelerated in the last several years. However, scientists have yet to quantitatively assess the efficiency of dynamic management over static management. Of particular interest is how scale influences effectiveness, both in terms of how it reflects underlying ecological processes and how this relates to potential efficiency gains. Here, we address the empirical evidence gap and further the ecological theory underpinning dynamic management. We illustrate, through the simulation of closures across a range of spatiotemporal scales, that dynamic ocean management can address previously intractable problems at scales associated with coactive and social patterns (e.g., competition, predation, niche partitioning, parasitism, and social aggregations). Furthermore, it can significantly improve the efficiency of management: as the resolution of the closures used increases (i.e., as the closures become more targeted), the percentage of target catch forgone or displaced decreases, the reduction ratio (bycatch/catch) increases, and the total time–area required to achieve the desired bycatch reduction decreases. In the scenario examined, coarser scale management measures (annual time–area closures and monthly full-fishery closures) would displace up to four to five times the target catch and require 100–200 times more square kilometer-days of closure than dynamic measures (grid-based closures and move-on rules). To achieve similar reductions in juvenile bycatch, the fishery would forgo or displace between USD 15–52 million in landings using a static approach over a dynamic management approach.