cssi/SciSciGPT-SciSciNet huggingface dataset:
Textured digital elevation model formation from low-cost UAV LADAR/digital image data

Textured digital elevation models (TDEMs) have valuable use in precision agriculture, situational awareness, and disaster response. However, scientific-quality models are expensive to obtain using conventional aircraft-based methods. The cost of creating an accurate textured terrain model can be reduced by using a low-cost (<$20k) UAV system fitted with ladar and electro-optical (EO) sensors. A texel camera fuses calibrated ladar and EO data upon simultaneous capture, creating a texel image. This eliminates the problem of fusing the data in a post-processing step and enables both 2D- and 3D-image registration techniques to be used. This paper describes formation of TDEMs using simulated data from a small UAV gathering swaths of texel images of the terrain below. Being a low-cost UAV, only a coarse knowledge of position and attitude is known, and thus both 2D- and 3D-image registration techniques must be used to register adjacent swaths of texel imagery to create a TDEM. The process of creating an aggregate texel image (a TDEM) from many smaller texel image swaths is described. The algorithm is seeded with the rough estimate of position and attitude of each capture. Details such as the required amount of texel image overlap, registration models, simulated flight patterns (level and turbulent), and texture image formation are presented. In addition, examples of such TDEMs are shown and analyzed for accuracy.
Understanding Uncertainty Shocks

For decades, macroeconomists have searched for shocks that are plausible drivers of business cycles. A recent advance in this quest has been to explore uncertainty shocks. Researchers use a variety of forecast and volatility data to justify heteroskedastic shocks in a model, which can then generate realistic cyclical uctuations. But the relevant measure of uncertainty in most models is the conditional variance of a forecast. When agents form such forecasts with state, parameter and model uncertainty, neither forecast dispersion nor innovation volatilities are good proxies for conditional forecast variance. We use observable data to select and estimate a forecasting model and then ask the model to inform us about what uncertainty shocks look like and why they arise.
Kids, cartoons, and cookies: Stereotype priming effects on children's food consumption

Abstract In studies with adult participants, exposure to a prime that activates a stereotype can lead to stereotype-consistent behavior. Given significant differences in cognitive development, stereotype formation, and use of stereotypes from early childhood to adulthood, the emergence of such behavioral priming effects in childhood is uncertain. To begin addressing whether children exhibit behavioral priming effects from stereotype exposure, we conduct three experiments in which children are exposed to either a normal weight or overweight cartoon character prime, and subsequently (as an unrelated activity) have access to high energy, low-nutrient food. Our results with children from 6 to 14 years old indicate that overweight cartoon character primes can activate the overweight stereotype, leading to relatively high levels of food intake. This effect persisted when participants were simultaneously exposed to a normal weight and an overweight character together (study 2), and was successfully moderated by the activation of health knowledge (study 3).
Asymmetric Synthesis of Deoxypropionate Derivatives via Catalytic Hydrogenolysis of Enantioenriched Z-Ketene Heterodimers

A diastereoselective approach to deoxypropionate derivatives through Pd/C-catalyzed hydrogenolysis of enantioenriched ketene heterodimers is described. Catalytic hydrogenolysis of the Z-isomer of ketene heterodimers facilitates access to anti-deoxypropionate derivatives (10 examples with dr 7:1 to >20:1). Transfer of chirality from the Z-ketene heterodimer to an acid product was good to excellent in most cases (78–99% ee for 12 examples).
Development and in silico Evaluation of Large-Scale Metabolite Identification Methods Using Functional Group Detection for Metabolomics

Large-scale identification of metabolites is key to elucidating and modeling metabolism at the systems level. Advances in metabolomics technologies, particularly ultra-high resolution mass spectrometry enable comprehensive and rapid analysis of metabolites. However, a significant barrier to meaningful data interpretation is the identification of a wide range of metabolites including unknowns and the determination of their role(s) in various metabolic networks. Chemoselective (CS) probes to tag metabolite functional groups combined with high mass accuracy provide additional structural constraints for metabolite identification and quantification. We have developed a novel algorithm, Chemically Aware Substructure Search (CASS) that efficiently detects functional groups within existing metabolite databases, allowing for combined molecular formula and functional group (from CS tagging) queries to aid in metabolite identification without a priori knowledge. Analysis of the isomeric compounds in both Human Metabolome Database (HMDB) and KEGG Ligand demonstrated a high percentage of isomeric molecular formulae (43% and 28% respectively), indicating the necessity for techniques such as CS-tagging. Furthermore, these two databases have only moderate overlap in molecular formulae. Thus, it is prudent to use multiple databases in metabolite assignment, since each major metabolite database represents different portions of metabolism within the biosphere. In silico analysis of various CS-tagging strategies under different conditions for adduct formation demonstrate that combined FT-MS derived molecular formulae and CS-tagging can uniquely identify up to 71% of KEGG and 37% of the combined KEGG/HMDB database versus 41% and 17% respectively without adduct formation. This difference between database isomer disambiguation highlights the strength of CS-tagging for non-lipid metabolite identification. However, unique identification of complex lipids still needs additional information.
A soft gamma-ray concentrator using thin-film multilayer structures

We have begun to investigate the use of thin-film, multilayer structures to form optics capable of concentrating soft gamma rays with energies greater than 100 keV, beyond the reach of current grazing-incidence hard X-ray mirrors. Alternating layers of low- and high-density materials (e.g., polymers and metals) will channel soft gamma-ray photons via total external reflection. A suitable arrangement of bent structures will then concentrate the incident radiation to a point. Gamma-ray optics made in this way offer the potential for soft gamma-ray telescopes with focal lengths of less than 10 m, removing the need for formation flying spacecraft and opening the field up to balloon-borne instruments. Building on initial investigations at Los Alamos National Laboratory, we are investigating whether it is possible to grow such flexible multi-layer structures with the required thicknesses and smoothness using magnetron sputter and pulsed laser deposition techniques. We present the initial results of tests aimed at fabricating such structures by combining magnetron sputtering with either spin coating or pulsed laser deposition, and demonstrating gamma-ray channeling of 122 keV photons in the laboratory. If successful, this technology offers the potential for transformational increases in sensitivity while dramatically improving the system-level performance of future high-energy astronomy missions through reduced mass and complexity.
International Trade Dynamics with Intermediate Inputs

increase in the relative number of importers in the economy. Following elimination of a 10% tariff, the calibrated model predicts a long-run doubling of the ratio of trade to GDP, with half of the increase occurring over the first ten years.
Navigability is a Robust Property

The Small World phenomenon has inspired researchers across a number of fields. A breakthrough in its understanding was made by Kleinberg who introduced Rank Based Augmentation RBA: add to each vertex independently an arc to a random destination, selected from a carefully crafted probability distribution. Kleinberg proved that RBA makes many networks navigable, i.e., it allows greedy routing to successfully deliver messages between any two vertices in a polylogarithmic number of steps. Our goal in this work is to prove that navigability is an inherent, robust property of many random networks, requiring no augmentation, coordination, or even independence assumptions. Our framework assigns a cost to each edge and considers the uniform measure over all graphs on n vertices that satisfy a total budget constraint. We show that when the cost function is sufficiently correlated with the underlying geometry of the vertices and for a wide range of budgets, the overwhelming majority of all feasible graphs with the given budget are navigable. We provide a new set of geometric conditions that generalize Kleinberg's set systems as well as a unified analysis of navigability.
Pyramid-based texture analysis/synthesis

This paper describes a method for synthesizing images that match the texture appearance of a given digitized sample. This synthesis is completely automatic and requires only the "target" texture as input. It allows generation of as much texture as desired so that any object can be covered. The approach is based on a model of human texture perception, and has potential to be a practically useful tool for image processing and graphics applications.
Principles and Applications of Rare Earth Ion-Doped Nanoparticles

This article presents some fundamental properties of nanoparticles of insulating materials doped with rare earth ions as optically active centers. In the nano-regime, the effects of confinement can affect the optical properties. These affects are well known in semiconductors such as CdS or CdSe, where the particle size dictates the band gap, and hence the particle’s absorption and emission properties. In the case of insulators, such affects are less important. For insulators, the optical properties are affected by the particle size mainly through (1) the reduced phonon density of states and (2) the role of the surface and near-surface sites occupied by the rare earth ion. In this article we examine the fundamental physics of these systems, and call attention to various experiments in which these affects have been observed.
Visual horizons in world-models

This paper seeks to effect a unification and generalization of various particular results on visual horizons scattered in the literature. A horizon is here defined as a frontier between things observable and things unobservable. Two quite different types of horizon exist which are here termed event-horizons and particle-horizons. These are discussed in detail and illustrated by examples and diagrams. The examples include well-known model-universes which exhibit one or the other type of horizon, both types at once, or no horizon. Proper distance and cosmic time are adopted as the main variables, and the analysis is based on the Robertson–Walker form of the line element and therefore applies to all cosmological theories using a homogeneous and isotropic substratum.
Packing-based approximation algorithm for the k -set cover problem

We present a packing-based approximation algorithm for the k-Set Cover problem. We introduce a new local search-based k-set packing heuristic, and call it Restricted k-Set Packing. We analyze its tight approximation ratio via a complicated combinatorial argument. Equipped with the Restricted k-Set Packing algorithm, our k-Set Cover algorithm is composed of the k-Set Packing heuristic [8] for k≥7, Restricted k-Set Packing for k=6,5,4 and the semi-local (2,1)-improvement [2] for 3-Set Cover. We show that our algorithm obtains a tight approximation ratio of $H_k-0.6402+\Theta(\frac{1}{k})$ , where Hk is the k-th harmonic number. For small k, our results are 1.8667 for k=6, 1.7333 for k=5 and 1.5208 for k=4. Our algorithm improves the currently best approximation ratio for the k-Set Cover problem of any k≥4.
Returns to scale and dynamics of multiple enterprises

This paper presents a dynamic theory of structural change in which functional change driven by technological change and transactional change open opportunity for change in scale and scope of enterprises. Implementation of change in scale and scope of enterprises is constrained by initial state conditions including resource endowments, access to credit, and regulation. In the presence of such constraints, the paper motivates the existence of thresholds that introduce cusps in the optimal paths of control variables. The evolution of enterprises is considered within the context of a multiple enterprise firm that encompasses discrete and continuous processes that are interdependent on intermediate goods as well as their production of environmental effects. Response to opportunity is governed as well by adjustment costs and incomplete markets. The specification is consistent with manufacturing, crop and animal agriculture, as well as service-oriented enterprises. Potential for structural change is considered within the context of changes in prices, regulation, and technological change. We discuss management options that maximize uncertain profit over the planning horizon subject to changing price regimes, regulations, and existing and new technology. We consider incentive as well as quota type policy to regulate environmental effects. While the model is one of optimal control, the presence of constraints opens the opportunity for timing of adjustment and constrains adjustment. We derive thresholds for change and show their principal determinants. Based on this specification, we derive an indicator of flexibility as well as real options style valuation of the benefits of postponement of adjustment. The model’s specification is sufficiently complex as to preempt analytical consideration. Instead, we specify a numerical example and present illustration of the implications of the model based on numerical computation. The example illustrates both unbundling of enterprises as conditions encourage reduction in scope as well as formation of relational links to recover what might be viewed as economies-of-scale by specialized enterprises spawned by unbundling. The example also illustrates conditions necessary to induce a shift from traditional grazing animal operations integrated with crops to intensive feed lots. Within this context, shift in scale, specialization, and scope of enterprises is illustrated. To conclude, the utility of model is considered within general contexts to analyze the structural implications of change in economic conditions such as shifts in price regimes, change in process technology, change in IT technology, and changes in institutional rules.
Further applications of holography to photoelasticity

Holographic method for reconstructing polarization of light emitted by photoelastic model, obtaining isochromatic and isoclinic fringe patterns
Rectilinear approximation of a set of points in the plane

We derive algorithms for approximating a set S of n points in the plane by an x-monotone rectilinear polyline with k horizontal segments. The quality of the approximation is measured by the maximum distance from a point in S to the segment above or below it. We consider two types of problems: min-e, where the goal is to minimize the error for k horizontal segments and min-#, where the goal is to minimize the number of segments for error e. After O(n) preprocessing time, we solve the latter in O(min{klogn, n}) time per instance. We then solve the former in O(min{n2, nklog n}) time. We also describe an approximation algorithm for the min-e problem that computes a solution within a factor of 3 of the optimal error for k segments, or with at most the same error as the k-optimal but using 2k–1 segments. Both approximations run in O(nlog n) time.
Optimal Technology, Development and the role of Government

This paper highlights the effect of the presence of the goverment and its redistribution policy in the technology adoption decision. As a result it helps explain the differences in skill premium patterns across the North Atlantic between developed economies such as the US and Continental Europe.
"Green Stimulus," Economic Recovery, and Long-Term Sustainable Development

This paper discusses short-run and long-run effects of "green stimulus" efforts, and compares these effects with non-green fiscal stimuli. Green stimulus is defined here as short-run fiscal stimuli that also serve a "green" or environmental purpose in a situation of "crisis" characterized by temporary under-employment. A number of recently enacted national stimulus packages contain sizeable "green" components. The authors categorize effects according to their a) short-run employment effects, b) long-run growth effects, c) effects on carbon emissions, and d)"co-benefit" effects (on the environment, natural resources, and for other externalities). The most beneficial "green" programs in times of crisis are those that can stimulate employment in the short run, and lead to large "learning curve" effects via lower production costs in the longer term. The overall assessment is that most "green stimulus" programs that have large short-run employment and environmental effects are likely to have less significant positive effects for long-run growth, and vice versa, implying a trade-off in many cases between short-run and long-run impacts. There are also trade-offs for employment generation in that programs that yield larger (smaller) employment effects tend to lead to more employment gains for largely lower-skilled (higher-skilled) workers, so that the long-term growth effects are relatively small (large). Ultimately, the results reinforce the point that different instruments are needed for addressing different problems.
The gentle art of external cephalic version.

Abstract Breech presentation and transverse lie are associated with rupture of the membranes, premature labor, prolapsed cord, and other fetal hazards. To reduce these risks, gentle external cephalic version was attempted for 860 single fetuses. The initial attempt succeeded in 781; subsequent attempts succeeded in 25. Some fetuses reconverted spontaneously to breech; repeat version was always successful. A total of 1,240 external versions were recorded. Of the fetuses of mothers who received any prenatal care, only 27 could not be converted to vertex (0.56 per cent of 4,817 single fetuses). External cephalic version may protect against the premature labors which are associated with breech presentations. Safety, success, optimum timing, and technique of external cephalic version are discussed.
A QCQP approach to triangulation

Triangulation of a three-dimensional point from n≥2 two-dimensional images can be formulated as a quadratically constrained quadratic program. We propose an algorithm to extract candidate solutions to this problem from its semidefinite programming relaxations. We then describe a sufficient condition and a polynomial time test for certifying when such a solution is optimal. This test has no false positives. Experiments indicate that false negatives are rare, and the algorithm has excellent performance in practice. We explain this phenomenon in terms of the geometry of the triangulation problem.
Efficiency in Public Procurement in Rural Road Projects of Nepal

Transport infrastructure is important for economic growth. In Nepal, about 20 percent of rural residents have to spend more than 3 hours to go to the nearest marketplace or agriculture center. Public procurement is an important policy instrument to use resources wisely and efficiently. This paper analyzes a series of policy questions, from procurement design to contract management and project quality assurance. The paper finds that the competition effect is significant. To enhance competition, bidding documents can be distributed free of charge on a website. The bid preparation period can be extended. Security issues are also found to be particularly important to avoid unnecessary cost overruns and project delays. Heavy rainfall and the bidders' low-balling strategy are identified as other factors of project delays. The quality of roads would deteriorate with not only security incidence but also time, precipitation and traffic volume.
Pattern Avoidance in Matchings and Partitions

Extending the notion of pattern avoidance in permutations, we study matchings and set partitions whose arc diagram representation avoids a given configuration of three arcs. These configurations, which generalize $3$-crossings and $3$-nestings, have an interpretation, in the case of matchings, in terms of patterns in full rook placements on Ferrers boards. We enumerate $312$-avoiding matchings and partitions, obtaining algebraic generating functions, in contrast with the known D-finite generating functions for the $321$-avoiding (i.e., $3$-noncrossing) case. Our approach provides a more direct proof of a formula of Bona for the number of $1342$-avoiding permutations. We also give a bijective proof of the shape-Wilf-equivalence of the patterns $321$ and $213$ which greatly simplifies existing proofs by Backelin-West-Xin and Jelinek, and provides an extension of work of Gouyou-Beauchamps for matchings with fixed points. Finally, we classify pairs of patterns of length 3 according to shape-Wilf-equivalence, and enumerate matchings and partitions avoiding a pair in most of the resulting equivalence classes.
Belts and Suspenders: Interactions Among Climate Policy Regulations

With few exceptions, economic analyses of "cap-and-trade" permit trading mechanisms for climate change mitigation have been based on first-best scenarios without pre-existing distortions or regulations. The reason is obvious: interactions between permit trading and other regulations will be complex. However, climate policy proposed for the U.S. will certainly interact with existing laws, and will also likely include additional regulatory changes with their own sets of interactions. Major bills introduced in the U.S. Congress have included both permit trading and traditional command and control regulations - a combination sometimes called "belts and suspenders." This paper discusses interactions between these instruments, and begins to lay out a framework for thinking about them systematically. The most important determinant of how the two types of instruments interact involves whether or not the cap-and-trade permit price would induce more or less abatement than mandated by the traditional standards alone. Moreover, economists' experience predicting the costs of environmental regulations suggests we are more likely to overestimate the costs of cap-and-trade, and therefore the price of carbon permits, than we are to overestimate the costs of a traditional regulatory standard, and that therefore the regulatory standards will likely reduce the cost-effectiveness benefits of cap-and-trade.
Interval-Based Decisions for Reasoning Systems

This essay looks at decision-making with interval-valued probability measures. Existing decision methods have either supplemented expected utility methods with additional criteria of optimality, or have attempted to supplement the interval-valued measures. We advocate a new approach, which makes the following questions moot: 1. which additional criteria to use, and 2. how wide intervals should be. In order to implement the approach, we need more epistemological information. Such information can be generated by a rule of acceptance with a parameter that allows various attitudes toward error, or can simply be declared. In sketch, the argument is: 1. probability intervals are useful and natural in A.I. systems; 2. wide intervals avoid error, but are useless in some risk-sensitive decision-making; 3. one may obtain narrower intervals if one is less cautious; 4. if bodies of knowledge can be ordered by their caution, one should perform the decision analysis with the acceptable body of knowledge that is the most cautious, of those that are useful. The resulting behavior differs from that of a behavioral probabilist (a Bayesian) because in the proposal, 5. intervals based on successive bodies of knowledge are not always nested; 6. if the agent uses a probability for a particular decision, she need not commit to that probability for credence or future decision; and 7. there may be no acceptable body of knowledge that is useful; hence, sometimes no decision is mandated.
Troubled Children and Children in Trouble: Redefining the Role of the Juvenile Court in the Lives of Children

This Essay considers the emerging research in the area of dual-jurisdiction children, often referred to as “crossover kids”—those currently or previously involved in maltreatment proceedings who have also committed delinquent acts. Part I describes the development of the juvenile courts in the early twentieth century. Part II of this Essay questions the need to “track” children along one legal path or another and points to the pitfalls of providing services to some children through a criminal justice paradigm instead of treating all children through a social work paradigm. Finally, Part III advocates a redesign of the juvenile court—a return to its roots—to better enable a court to consider the needs of the whole child, in context with the needs of her/his family.
Planning for Network-Aware Paths

Communication in distributed applications across a wide area network needs to cope with heterogenous and constantly changing network conditions. A promising approach to address this is to augment the whole communication path with network awareness by using “bridging” components that are capable of caching, protocol conversion, transcoding, etc. While several such path-based approaches have been proposed, current approaches lack mechanisms for automatically creating effective network paths whose performance is optimized for encountered network conditions.
(Un)Employment Dynamics: The Case of Monetary Policy Shocks

This paper estimates an identified VAR on US data to gauge the dynamic response of the job finding rate, the worker separation rate, and vacancies to monetary policy shocks. I develop a general equilibrium model that can account for the large and persistent responses of vacancies, the job finding rate, the smaller but distinct response of the separation rate, and the inertial response of inflation. The model incorporates labor market frictions, capital accumulation, and nominal price rigidities. Special attention is paid to the role of different propagation mechanisms and the impact of search frictions on marginal costs. Estimates of selected parameters of the model show that wage rigidity, moderate search costs, and a high value of non-market activities are important in explaining the dynamic response of the economy. The analysis extends to a broader set of aggregate shocks and can be used to understand and design monetary, labor market, and other policies in the presence of labor market frictions
RheoStat: Real-Time Risk Management

As the frequency of attacks faced by the average host connected to the Internet increases, reliance on manual intervention for response is decreasingly tenable. Operating system and application based mechanisms for automated response are increasingly needed. Existing solutions have either been customized to specific attacks, such as disabling an account after a number of authentication failures, or utilize harsh measures, such as shutting the system down. In contrast, we present a framework for systematic fine grained response that is achieved by dynamically controlling the host’s exposure to perceived threats.
A multiview approach to tracking people in crowded scenes using a planar homography constraint

Occlusion and lack of visibility in dense crowded scenes make it very difficult to track individual people correctly and consistently. This problem is particularly hard to tackle in single camera systems. We present a multi-view approach to tracking people in crowded scenes where people may be partially or completely occluding each other. Our approach is to use multiple views in synergy so that information from all views is combined to detect objects. To achieve this we present a novel planar homography constraint to resolve occlusions and robustly determine locations on the ground plane corresponding to the feet of the people. To find tracks we obtain feet regions over a window of frames and stack them creating a space time volume. Feet regions belonging to the same person form contiguous spatio-temporal regions that are clustered using a graph cuts segmentation approach. Each cluster is the track of a person and a slice in time of this cluster gives the tracked location. Experimental results are shown in scenes of dense crowds where severe occlusions are quite common. The algorithm is able to accurately track people in all views maintaining correct correspondences across views. Our algorithm is ideally suited for conditions when occlusions between people would seriously hamper tracking performance or if there simply are not enough features to distinguish between different people.
The role of schools in the production of achievement

What explains dierences in pre-market factors? Three types of inputs are believed to determine the skills agents take to the labor market: ability, family inputs and school inputs. Therefore to answer the previous question it is crucial to understand …rst the importance of each of those inputs. The literature on the production of achievement has not been able to provide an estimation that can take the three factors into account simultaneously at the student level. This paper intends to …ll this gap by providing an estimation of the production function of achievement where both types of investments (families and schools) are considered in a framework where the inputs are allowed to be correlated with the unobserved term, ability to learn. I do that by applying Olley and Pakes'(1996) algorithm which accommodates for endogeneity problems in the choice of inputs for the production of achievement and by using parents'saving for their child's postsecondary education to control for the unobserved component (i.e. ability to learn) in the production of skills. The estimates for the role of family inputs are in line to previous …ndings. Additionally, the estimates of school inputs show that they are also important for the formation of students'skills even after controlling for ability to learn.
Luteinized unruptured follicle syndrome: a subtle cause of infertility.

A clinical description of luteinized unruptured follicles is presented. This abnormality in ovulation is characterized by normal endocrinologic presumptive signs of ovulation: biphasic basal body temperature curves, secretory endometrium, and laboratory evidence of progesterone production by elevated urinary pregnanediol or plasma progesterone levels In a group of 102 such infertile women, laparoscopy performed 3 to 5 days after apparent ovulation revealed the absence of a corpus hemorrhagicum in 30 women, and the absence of a stigma on a corpus hemorrhagicum in an additional 32 women. These findings were evidence that a follicle had not ruptured and an ovum had not escaped. Of 28 patients undergoing follicular stimulation with clomiphene citrate or human menopausal gonadotropin after this diagnosis, 15 conceived.
Non-robustness of the cash-in-advance equilibrium in the trading post model

The main justification for cash-in-advance (CIA) equilibria when there are multiple assets is a Shapley-Shubik trading-post model where the agents coordinate on a particular medium of exchange. Of course, there are other equilibria. We introduce a refinement and show that the CIA equilibrium does not satisfy our refinement while there exist equilibria that do.
Polychotomic Encoding: A Better Quasi-Optimal Bit-Vector Encoding of Tree Hierarchies

Polychotomic Encoding is an algorithm for producing bit vector encodings of trees. Polychotomic Encoding is an extension of the Dichotomic Encoding algorithm of Raynaud and Thierry. Polychotomic and Dichotomic Encodings are both examples of hierarchical encoding algorithms, where each node in the tree is given a gene--a subset of {1, . . . , n}. The encoding of each node is then the union of that node's gene with the genes of its ancestors. Reachability in the tree can then be determined by subset testing on the encodings.Dichotomic Encoding restructures the given tree into a binary tree, and then assigns two bit, incompatible (chotomic) "genes" to each of the two children of a node. Polychotomic Encoding substitutes a multibit encoding for the children of a node when the restructuring operation of Dichotomic Encoding would produce a new heaviest child (child requiring the most bits to represent a tree of its children) for that node. The paper includes a proof that Polychotomic Encoding never produces an encoding using more bits than Dichotomic Encoding. Experimentally, Polychotomic Encoding produces a space savings of up to 15% on examples of naturally occurring hierarchies, and 25% on trees in the randomly generated test set.
Currents in the Earth's Magnetotail

Currents in the earth's magnetotail are detected with the plasma instrumentation on board the ISEE-1 spacecraft. Field-aligned currents directed into and out of the ionosphere are found in the boundary layer of the plasma sheet. Typical current densities are in the range of 5 x 10-9 to 5 x 10-8 A/m2. These currents are associated with the Region 1 current system that is observed previously at low altitudes. An intense current sheet is shown to exist at a discontinuity in convection electric fields during a period of great magnetic activity. Electron acceleration, similar to that for electron inverted-V precipitation regions at low altitudes, occurs in this current sheet. Examination of the plasma velocity distributions at a neutral-sheet crossing reveals that the neutral sheet current is carried by electrons and protons. The relative directions for the bulk flows of the proton and electron plasmas indicate that the first adiabatic invariant is not conserved for the protons, and quite possibly for the electrons also. These letter findings are in substantial agreement with a neutral sheet model for acceleration of charged particles in the presence of a weak electric field.
Modeling dynamic adjustment in Japanese livestock markets under trade liberalization.

The dynamic adjustment of Japanese livestock markets is analyzed under three alternative import policies: the 1988 Japanese Beef Market Access Agreement (BMAA), the tariffication proposal to the General Agreement on Tariffs and Trade (GATT) negotiations, and the complete liberalization of Japanese beef import policies. Modeling problems associated with these policies include the change from a quota to a tariff and the choice of a tariff reduction path. A proposed formula for the adjustment path of the tariff reduction is designed to buffer the transfer of world price volatility while achieving the goal of reducing trade barriers;Problems associated with the incorporation of meat demand systems derived from utility-maximizing behavior into livestock policy models are examined. These problems include complementarity, issues of aggregation, levels of substitutability, and estimation problems. The changes in the degree of producer supply responsiveness under alternative policies are also discussed. An econometric model of the Japanese livestock industry is then used to simulate the impact of the BMAA, the GATT tariff reduction proposal, and the complete liberalization of beef imports from 1988 to 1997;The projected levels of beef imports under the alternative import policies suggest that the potential market for beef in Japan will be over 1.6 million mt by 1991 and over 2 million mt by 1997. During the transition phase of the BMAA, beef imports are projected to increase to the quota level each year. During the post-transition phase, an additional 20 percent tariff provision will be invoked. Beef imports are projected to increase by over 67 percent in 1991 under the BMAA and to reach 1.232 million mt by 1997. The BMAA and the GATT tariff reduction results are similar until 1994 when the BMAA tariff levels off at 50 percent.
A new proof for the number of lozenge tilings of quartered hexagons

It has been proven that the lozenge tilings of a quartered hexagon on the triangular lattice are enumerated by a simple product formula. In this paper we give a new proof for the tiling formula by using Kuo's graphical condensation. Our result generalizes a result of Proctor on enumeration of plane partitions contained in a "maximal staircase".
Wave propagation in transversely impacted composite laminates

An experimental study was conducted to determine the wave-propagation characteristics, transient strains and residual properties of unidirectional and angle-ply boron/epoxy and graphite/epoxy laminates impacted with silicon-rubber projectiles at velocities up to 250 m/sec. Results include the following: (1) the predominant wave is the flexural wave propagating at different velocities in different directions; (2) peak strains and strain rates in the transverse to the (outer) fiber direction are much higher than those in the direction of the fibers; (3) strain rates up to 640/sec were measured; and (4) unidirectional laminates under impact showed appreciable modulus and strength degradation in the direction transverse to fibers.
Risk Preference Differentials of Small Groups and Individuals

The risk prefer ences of thr ee-person group s a nd individuals are compar ed using a non- sequential repeated-measures lottery exp eriment w ith $20 per-player win pe rcentages varying from 10% to 90%. Analysis based on independent samples of certainty equivalent ratios (certainty equivalent/expected value) elicited using a maximum willingness-to-pay mechanism for fifty-two individuals and sixteen groups reveals that: 1) certainty equi valent ratios ( CERs) va ry significantly a cross lottery win percentages, 2) CER dispersion tends to decline as the lottery win percentage increases and is significantly smaller for groups than individuals in seven of the nine lotteries, 3) for the highest-risk lotteries, the average CERs submitted by groups are significantly smaller (more risk averse) than the average CERs submitted by individuals, 4) for the lowest-risk lotteries, the average CERs submitted by groups are approximately risk-neutral (CER=1) and somewhat larger than the average CERs submitted by individuals.
Economic Issues Related To Chickpea Production In The Northern Plains

Some crop producers in the Northern Plains have added chickpeas to traditional crop rotations. In the United States, chickpeas have historically been produced in California, Oregon, and Washington. Measurable amounts of chickpea production have only recently occurred in Montana and North Dakota. Agronomic, production, and marketing management of chickpeas may be quite different from that for more commonly-grown crops. This Briefing addresses economic issues related to chickpea production, marketing, and risk management in the Northern Plains.
Generating linkage disequilibrium patterns in data simulations using genomeSIMLA

Whole-genome association (WGA) studies are becoming a common tool for the exploration of the genetic components of common disease. The analysis of such large scale data presents unique analytical challenges, including problems of multiple testing, correlated independent variables, and large multivariate model spaces. These issues have prompted the development of novel computational approaches. Thorough, extensive simulation studies are a necessity for methods development work to evaluate the power and validity of novel approaches. Many data simulation packages exist, however, the resulting data is often overly simplistic and does not compare to the complexity of real data; especially with respect to linkage disequilibrium (LD). To overcome this limitation, we have developed genomeSIMLA. GenomeSIMLA is a forward-time population simulation method that can simulate realistic patterns of LD in both family-based and case-control datasets. In this manuscript, we demonstrate how LD patterns of the simulated data change under different population growth curve parameter initialization settings. These results provide guidelines to simulate WGA datasets whose properties resemble the HapMap.
CuIn1−xGaxSe2-based photovoltaic cells from electrodeposited precursor films

We have developed an electrodeposition bath based on a buffer solution so that the stability of the electrodeposition process is enhanced and no metal oxides or hydroxides precipitate out of solution. The buffer-solution-based bath also deposits more gallium in the precursor films. As-deposited precursors are stoichiometric or slightly Cu-rich CuIn1−xGaxSe2. Only a minimal amount of indium was added to the electrodeposited precursor films by physical vapor deposition to obtain a 9.4%-efficient device.
Linear response methods for accurate covariance estimates from Mean field variational Bayes

Mean field variational Bayes (MFVB) is a popular posterior approximation method due to its fast runtime on large-scale data sets. However, a well known major failing of MFVB is that it underestimates the uncertainty of model variables (sometimes severely) and provides no information about model variable covariance. We generalize linear response methods from statistical physics to deliver accurate uncertainty estimates for model variables—both for individual variables and coherently across variables. We call our method linear response variational Bayes (LRVB). When the MFVB posterior approximation is in the exponential family, LRVB has a simple, analytic form, even for non-conjugate models. Indeed, we make no assumptions about the form of the true posterior. We demonstrate the accuracy and scalability of our method on a range of models for both simulated and real data.
Limits to Open Class Performance

This viewgraph presentation describes the limits to open class performance. The contents include: 1) Standard Class; 2) 15m/Racing Class; 3) Open Class; and 4) Design Solutions associated with assumptions, limiting parameters, airfoil performance, current trends, and analysis.
Analysis of the regional impacts of Climate Policy in Japan

After great improvements in energy efficiency in the 1970’s, Japan has made little progress in reducing energy consumption since 1990, the base year for the Kyoto Protocol. This study is motivated by the recent growing demands among policy makers to find all possibilities for saving energy. To make informed decisions on how to save energy, policy makers need detailed information on energy consumption structures within each jurisdiction. First, in this article, I decompose national level energy intensity into efficiency and activity effects with the Fisher Ideal index, and then estimate regressions on prefecture level residential electricity demand between 1990 and 2003. It is found that national level energy intensity declined by seventy three percent from 1970 to 2003; sixty three percent of the decline may be attributed to improvement in energy efficiency. Energy intensity, however, has slightly increased since early 1990’s. Secondly, this paper explores the impact of reduction of carbon emission on the economy. I find that the Japanese government needs to enact the environmental taxes on a $12/ton in order to meet the Kyoto Protocol. It is also found that imposing a $12/ton environmental tax reduces Japanese GDP by around six percent and equivalent variations in urban regions fall while equivalent variations in rural regions rise.
Descriptions of hadronic structure

I would like to devote this lecture to discussing two topics: the evolution of the quark model and the problem of quark confinement. By way of introduction, however, I must stress that after ten years of relative stability, high energy physics is again in a state of flux. At this point, therefore, I had better deal only with generalities. A few significant points characterize the general pattern of the present situation. First there is an evolution of the quark model leading to a proliferation of fundamental constituents. This is of course related to the discovery of new particles. But quantum numbers alone do not seem enough this time, unlike the days of strange particles. New dynamics may also be necessary. An example is the Zweig-Iizuka rule, but asymptotic freedom, quark confinement, etc., must also be included as part of the general problem. One can even speculate that a new post-quantum mechanics is hidden somewhere, although this may be going too far.
Morse theory and toric vector bundles

Morelli's computation of the K-theory of a toric variety X associates a polyhedrally constructible function on a real vector space to every equivariant vector bundle E on X. The coherent-constructible correspondence lifts Morelli's constructible function to a complex of constructible sheaves kappa(E). We show that certain filtrations of the cohomology of kappa(E) coming from Morse theory coincide with the Klyachko filtrations of the generic stalk of E. We give Morse-theoretic (i.e. microlocal) conditions for a complex of constructible sheaves to correspond to a vector bundle, and to a nef vector bundle.
Dynamic reserve zones for day-ahead unit commitment with renewable resources

As more non-dispatchable renewable resources are integrated into the grid, it will become increasingly difficult to predict the transfer capabilities and the network congestion. At the same time, renewable resources require operators to acquire more operating reserves. With today's deterministic reserve requirements unable to ensure optimal reserve locations, improvements to re-serve policies are needed to ensure reserve deliverability while maintaining a reliable system at least cost. This paper proposes a daily reserve zone determination procedure, which is able to reflect system operating conditions by utilizing probabilistic power flows. A statistical clustering algorithm is used to cluster buses together to produce the zones; the algorithm uses a centrality measurement, which is based on weighted power transfer distribution factors. The proposed method is validated by testing it on a modified IEEE 118-bus system for multiple days; the proposed method is compared against existing reserve zone partitioning procedures. While the proposed reserve zone determination method is a heuristic, it is shown to be effective and it is a computationally tractable method. The proposed method can be used on its own and can be used along with stochastic programming techniques that implicitly determine reserves.
Is the Sun Embedded in a Typical Interstellar Cloud

Interstellar material around the Sun is typical for our neighborhood of the Galaxy. The physical properties and kinematics of the partially ionized interstellar material (ISM) near the Sun are typical of warm diffuse clouds in the solar vicinity. The direction of the interstellar magnetic field at the heliosphere, the polarization of light from nearby stars, and the kinematics of nearby clouds are naturally explained in terms of the S1 superbubble shell. The interstellar radiation field at the Sun appears to be harder than the field ionizing ambient diffuse gas, which may be a consequence of the low opacity of the tiny cloud surrounding the heliosphere.
Stability of C^*-algebras associated to graphs

We characterize stability of graph C*-algebras by giving five conditions equivalent to their stability. We also show that if G is a graph with no sources, then C*(G) is stable if and only if each vertex in G can be reached by an infinite number of vertices. We use this characterization to realize the stabilization of a graph C*-algebra. Specifically, if G is a graph and G is the graph formed by adding a head to each vertex of G, then C*(G) is the stabilization of C*(G); that is, C*(G) ≅ C*(G) ⊗ K.
Distributed construction of quantum fingerprints

Quantum fingerprints are useful quantum encodings introduced by Buhrman, Cleve, Watrous and de Wolf (Physical Review Letters, Volume 87, Number 16, Article 167902, 2001) to obtaia an efficient quantum communication protocol. We design a protocol for constructing the fingerprint in a dlstributed scenario. As an application, this protocol gives rise to a communication protocol more efficient than the best known classical protocol for a communicatioa problem.