cssi/SciSciGPT-SciSciNet huggingface dataset:
A succinct way to diagonalize the translation matrix in three dimensions

The fast multipole method is an effective way to expedite iterative solutions of integral equations for electrodynamic and elastodynamic problems. Iterative solvers, such as the conjugate gradient method, require matrix vector multiplies, and for dense matrices, these matrix-vector multiplies constitute the predominant computational cost as well as requiring a large memory. The fast multipole method is based on the translation of multipoles from one coordinate system to another, which is achieved by using translation matrices. However, the mere use of translation matrices does not reduce the computational cost nor the memory requirement for dynamic problems involving surface scatterers. For such problems, the crucial step in the fast multipole method is the diagonalization of the translation operators. The translation matrix for the three dimensional Helmholtz wave equation has been successfully diagonalized using an alternative and succinct method. The method reveals the relationship between the translation matrices and their representation of the translation group. A diagonalization is expected under a plane-wave basis for the representation since a plane-wave basis forms an irreducible representation for the translation group. Hence, the diagonalization of the translation matrices from the spherical harmonic representation can be viewed as a series of similarity transforms. The result can be used in the fast multipole method and the multilevel fast multipole method where multiple scattering involves interaction between multipoles.
Coethnic Bias and Wartime Informing

Information about insurgent groups is a central resource in civil wars: counterinsurgents seek it, insurgents safeguard it, and civilians often trade it. Yet despite its essential role in civil war dynamics, the act of informing is still poorly understood, due mostly to the classified nature of informant “tips.” As an alternative research strategy, we use an original 2,700 respondent survey experiment in 100 villages to examine attitudes toward the Guardians of Peace program, a widespread campaign by the International Security Assistance Force in Afghanistan to recruit local informants. We find that coethnic bias—the systematic tendency to favor cooperation with coethnics—shapes attitudes about informing and beliefs about retaliation, especially among Tajik respondents. This bias persists even after adjusting for additional explanations and potential confounding variables, suggesting that identity considerations such as coethnicity may influence attitudes toward high-risk behavior in wartime settings.
Economic Foundations of Symmetric Programming

1. Introduction 2. Lagrangean theory 3. Karush-Kuhn-Tucker theory 4. Solving systems of linear equations 5. Asymmetric and symmetric quadratic programming 6. Linear complementarity problem 7. The price taker 8. The monopolist 9. The monopsonist 10. Risk programming 11. Comparative statics and parametric programming 12. General market equilibrium 13. Two-person zero- and non-zero-sum games 14. Positive mathematical programming 15. Multiple optimal solutions 16. Lemke complementary pivot algorithm - user manual 17. Lemke Fortran 77 program.
WHO WINS RESIDENTIAL PROPERTY TAX APPEALS

This article explains who wins residential property tax appeals in Cook County, Illinois. It does so by collecting and combining public sector data, which has been recently released by the Cook County Assessor. The article then uses this data to compute three statistics. Lastly, it contextualizes each statistic in order to determine if some townships, or groups of townships, win more appeals than expected. 210 COLUMBIA JOURNAL OF TAX LAW [Vol.6:209
Phospholipid-dextran with a single coupling point : a useful amphiphile for functionalization of nanomaterials

Nanomaterials hold much promise for biological applications, but they require appropriate functionalization to provide biocompatibility in biological environments. For non-covalent functionalization with biocompatible polymers, the polymer must also remain attached to the nanomaterial after removal of its excess to mimic the high dilution conditions of administration in vivo. Reported here are the synthesis and utilization singly-substituted conjugates of dextran and a phospholipid (Dextran-DSPE) as stable coatings for nanomaterials. Suspensions of single walled carbon nanotubes were found not only to be stable to phosphate buffered saline (PBS), serum, and a variety of pH’s after excess polymer removal, but also provide brighter photoluminescence than carbon nanotubes suspended by poly(ethylene glycol)-DSPE. In addition, both gold nanoparticles (AuNPs) and gold nanorods (AuNRs) were found to maintain their dispersion and characteristic optical absorbance after transfer into Dextran-DSPE, and were obtained in much better yield than similar suspensions with PEG-phospholipid and commonly used thiol-PEG. These suspensions were also stable to PBS, serum, and a variety of pH’s after removal of excess polymer. Dextran-DSPE thus shows great promise as a general surfactant material for the functionalization of a variety of nanomaterials, which could facilitate future biological applications.
Effect of Mutual Coupling on the Performance of GPS AJ Antennas

In this paper, the effects of mutual coupling on the performance of GPS anti-jam antennas are discussed. For space-only processing (SOP) based adaptive antennas operating in the presence of CW interfering signals, it is shown that the performance with mutual coupling is similar to the performance in the absence of mutual coupling. The performance of the adaptive antenna degrades when wide-band interfering signals are introduced. The degradation with mutual coupling is larger than when mutual coupling is excluded in the performance evaluation. Furthermore, it is demonstrated that the improper design of individual elements can be the cause of this performance degradation. Space-time adaptive processing (STAP) is shown to recover the lost performance that SOP based adaptive antennas incur in the presence of wide-band interference. Finally, it is demonstrated that improper element design can be a cause of performance degradation even when STAP is used.
Making an IMPACT: Campus-wide collaboration for course and learning space transformation

At Purdue University, the Libraries participate in a provost-initiated, campus-wide course redesign program called Instruction Matters: Purdue Academic Course Transformation (IMPACT). This initiative aims to bring active-learning to foundational courses traditionally taught through lectures. Purdue librarians recognized the IMPACT initiative as one way to enter the conversations blooming on our campus about the nature of learning, curriculum design, and how space design impacts potential learning. This article presents three perspectives: 1) the information literacy coordinator, 2) a libraries’ administrator with a gift for space planning, and; 3) an in-the-trenches liaison to course redesign projects. Each discusses the IMPACT initiative from his or her unique perspective and view of its impact on librarian roles. Collectively, the article explains why we think it is essential that this kind of campus effort is supported by libraries.
On the structure of rationalizability for arbitrary spaces of uncertainty

Weinstein and Yildiz (2007) show that only very weak predictions are robust to misspecifications of higher order beliefs. Whenever a type has multiple rationalizable actions, any of these actions is uniquely rationalizable for some arbitrarily close type. Hence, refinements of rationalizability are not robust. This negative result is obtained under a richness condition, which essentially means that all common knowledge assumptions on payoffs are relaxed. In many settings, this condition entails an unnecessarily demanding robustness test. It is, therefore, natural to explore the structure of rationalizability when arbitrary common knowledge assumptions are relaxed (i.e., without assuming richness). For arbitrary spaces of uncertainty and for every player i, I construct a set A ∞ of actions that are uniquely rationalizable for some hierarchy of beliefs. The main result shows that for any type ti and any action ai rationalizable for ti ,i fai belongs to A ∞ and is justified by conjectures concentrated on A ∞ , then there exists a sequence of types converging to ti for which ai is uniquely rationalizable. This result significantly generalizes Weinstein and Yildiz’s. Some of its implications are discussed in the context of auctions and equilibrium refinements, and in connection with the literature on global games.
Arenicolides A−C, 26-Membered Ring Macrolides from the Marine Actinomycete Salinispora arenicola

Chemical evaluation of the saline fermentation broth of several strains of the obligate marine actinomycete Salinispora arenicola has led to the identification of three new macrolide polyketides designated arenicolides A-C (1-3). The planar structures, elucidated via spectroscopic and chemical methods, consist of 26-membered polyunsaturated macrolactones containing repeating vicinal hydroxyl methoxyl moieties. The relative and absolute stereochemistries of 1-3 were assigned by a combination of J-based configurational analyses and chemical derivatization.
Using ultrasonic measurements and a two-phase composite model to assess radiation damage in reactor pressure vessel steels

Ultrasonic methods used in the study of radiation damage and recovery in single crystals appear to also be useful for similar studies on polycrystalline alloys. Ultrasonic methods have demonstrated a sensitivity to radiation damage as affected by neutron fluence, irradiation temperature, large changes in composition, and possibly, as well, by neutron energy spectrum. On the microstructure defect evolution, only the residual defects created through the radiation event will contribute to the final macroscopic material property change. From a microstructure point, it is generally accepted that radiation hardening and embrittlement in metals are caused by clusters of vacancies, interstitial, and solute atoms that impede the motion of slip dislocations. Although vacancy-type defects are a major contributor to the material hardening, they also indicate the presence of other interstitial defects. Thus the total volume change of vacancy-type defects before and after irradiation can serve as a direct index to the final material property changes. The volume change of the vacancy-type defects can be determined by utilizing the two -phase composite model (matrix and void-type inclusion) to interpret wave velocities of baseline and irradiated specimens that are obtained from the ultrasonic wave experiment. This is a relatively economic and straightforward procedure. The correlationmore » of the volume change of the vacancy-type defects with the existing destructive mechanical test results may play an important role in the future for the prediction of the radiation embrittlement and remaining plant lifetime, especially for the older plants on the verge of exhausting all the available mechanical test specimens loaded in the surveillance capsules. The above hypothesis was supported by the limited irradiated data analyzed and presented in his paper. The proposed ultrasonic methodology also has a potential application to assess creep damage in fossil power plants.« less
Single-grating and single-grism pulse compressors

We introduce single-grating and single-grism pulse compressors, which are compact and automatically aligned for distortion-free output, and the latter of which compensates for significant material dispersion up to third order.
Variations on Information Embedding in Multiple Access and Broadcast Channels

Information embedding (IE) is the transmission of information within a host signal subject to a distortion constraint. There are two types of embedding methods, namely irreversible IE and reversible IE, depending upon whether or not the host, as well as the message, is recovered at the decoder. In irreversible IE, only the embedded message is recovered at the decoder, and in reversible IE, both the message and the host are recovered at the decoder. In this paper, combinations of irreversible and reversible IE in multiple access channels (MAC) and physically degraded broadcast channels (BC) are considered. In this paper, MAC IE in which separate encoders embed their messages into their host signals subject to distortion constraints is considered. The embedded signals from the two encoders are transmitted to a single decoder across a MAC. For the MAC IE model, the following three cases are considered: A) no host recovery at the decoder, B) lossless recovery of one host at the decoder, and C) lossless recovery of both hosts at the decoder. For the cases A and B, inner bounds on the respective capacity regions are developed. For the case C, inner and outer bounds on the capacity region are developed, and the capacity region is obtained if the hosts are independent. In this paper, BC IE in which two messages intended for separate decoders are embedded into a given host sequence by a single encoder subject to a distortion constraint is also considered. For the BC IE model, the following four cases are considered: A') lossless recovery of the host sequence at neither of the decoders, B') lossless recovery of the host sequence at only the better decoder, C') lossless recovery of the host sequence at both decoders, and D') lossless recovery of the host sequence at only the worse decoder. For cases A' and B', inner and outer bounds on the respective capacity regions are developed. For cases C' and D', the identical capacity regions are obtained.
Performance of a distributed robotic system using shared communications channels

We have designed and built a set of miniature robots called Scouts and have developed a distributed software system to control them. This paper addresses the fundamental choices we made in the design of the control software, describes experimental results in a surveillance task, and analyzes the factors that affect robot performance. Space and power limitations on the Scouts severely restrict the computational power of their on-board computers, requiring a proxy-processing scheme in which the robots depend on remote computers for their computing needs. While this allows the robots to be autonomous, the fact that robots' behaviors are executed remotely introduces an additional complication-sensor data and motion commands have to be exchanged using wireless communications channels. Communications channels cannot always be shared, thus requiring the robots to obtain exclusive access to them. We present experimental results on a surveillance task in which multiple robots patrol an area and watch for motion. We discuss how the limited communications bandwidth affects robot performance in accomplishing the task, and analyze how performance depends on the number of robots that share the bandwidth.
Control and System Design for the Czochralski Crystal Growth Process

An expanded set of control objectives is proposed for the Czochralski crystal growth process. Consideration of the thermal stress near the interface yields an operating regime specification in terms of interface shape. A lumped parameter model is used to determine the performance of alternate inputs and outputs. Based on these considerations, a new control structure is proposed to maintain crystal diameter, interface shape, and thermal gradients throughout the batch growth cycle. The performance of alternative control structures are evaluated
Testing k-modal distributions: optimal algorithms via reductions

We give highly efficient algorithms, and almost matching lower bounds, for a range of basic statistical problems that involve testing and estimating the L1 (total variation) distance between two k-modal distributions p and q over the discrete domain {1,..., n}. More precisely, we consider the following four problems: given sample access to an unknown k-modal distribution p,Testing identity to a known or unknown distribution:1. Determine whether p = q (for an explicitly given k-modal distribution q) versus p is e-far from q;2. Determine whether p = q (where q is available via sample access) versus p is e-far from q;Estimating L1 distance ("tolerant testing") against a known or unknown distribution:3. Approximate dTV(p, q) to within additive e where q is an explicitly given k-modal distribution q;4. Approximate dTV(p, q) to within additive e where q is available via sample access.For each of these four problems we give sub-logarithmic sample algorithms, and show that our algorithms have optimal sample complexity up to additive poly(k) and multiplicative polylog log n + polylogk factors. Our algorithms significantly improve the previous results of [BKR04], which were for testing identity of distributions (items (1) and (2) above) in the special cases k = 0 (monotone distributions) and k = 1 (unimodal distributions) and required O((log n)3) samples.As our main conceptual contribution, we introduce a new reduction-based approach for distribution-testing problems that lets us obtain all the above results in a unified way. Roughly speaking, this approach enables us to transform various distribution testing problems for k-modal distributions over {1,..., n} to the corresponding distribution testing problems for unrestricted distributions over a much smaller domain {1,..., e} where e = O(k log n).
Congestion estimation during top-down placement

Congestion is one of the fundamental issues in very large scale integration physical design. In this paper, we propose two congestion-estimation approaches for early placement stages. First, we theoretically analyze the peak-congestion value of the design and experimentally validate the estimation approach. Second, we estimate regional congestion at the early stages of top-down placement. This is done by combining the wire-length distribution model and interregion wire estimation. Both approaches are based on the well-known Rent's rule, which is previously used for wirelength estimation. This is the first attempt to predict congestion using Rent's rule. The estimation results are compared with the layout after placement and global routing. Experiments on large industry circuits show that the early congestion estimation based on Rent's rule is a promising approach.
A 6-GSamples/s multi-level decision feedback equalizer embedded in a 4-bit time-interleaved pipeline A/D converter

A 4-bit 6-GS/s pipeline A/D converter with 10-way time-interleaving is demonstrated in a 0.18-/spl mu/m CMOS technology. The A/D converter is designed for a serial-link receiver and features an embedded adjustable single-tap DFE for channel equalization. The ISI subtraction of the DFE is performed at the output of each pipeline stage; hence the effective feedback delay requirement is relaxed by 6/spl times/. Code-overlapping of the 1.5-bit pipeline stage along with digital error correction is used to absorb and remove the remainder of the ISI. The measured A/D converter performance at 6-GSamples/s shows 22.5 dB of low-frequency input SNDR for the calibrated A/D converter with /spl plusmn/0.25 LSB and /spl plusmn/0.4 LSB of INL and DNL, respectively. The input capacitance is 170 fF for each A/D converter. The DFE tap coefficient is adjustable from 0 to 0.25 with 6-bits of programmable weight. With a DFE coefficient of 0.2, the measured DFE performance shows 2.5 dB of amplitude boosting for a 3-GHz input sinusoid. The 1.8/spl times/1.6 mm/sup 2/ chip consumes 780 mW of power from a 1.8-V power supply.
Stabilization Theory and Policy: 50 Years after the Phillips Curve

This paper discusses the impact of A.W.H. Phillips’ seminal work in macroeconomic stabilization policy on subsequent developments in that field. We begin by reviewing the various stabilization rules adopted by Phillips and show how these relate to optimal stabilization rules that emerge from linear-quadratic optimization problems. Most of the early st abilization literature was associated with “backward looking” variables. The development of rational expectations in the 1960’s and 1970’s posed a challenge for stabilization policy. This arose from the role of “forward -looking” inflationary expectations in the Phillips curve, and the effect this had on the design of optimal stabilization rules, through issues such as the “Lucas Critique” and the “time consistency” of policy. We also briefly comment on a long-standing debate, pertaining to the merits of fixed policy rules versus discretionary or optimal policy. The latter part of the paper discusses some of the more contemporary aspects of stabilization policy, thereby serving to illustrate the durability of Phillips’ contributions.
Systems engineering: a practical approach for junior engineers

This paper discusses a recent engineering graduate's viewpoint(s) about his career with the United States Air Force. He discusses the importance of undergraduate engineering disciplines being taught with respect to systems engineering guidelines and how systems engineering should also be taught from a practical viewpoint. If the systems engineering process is added to the traditional engineering curriculum, it should highlight the war-fighter's or customer's needs, specifications, standards, and requirements. This paper stresses the idea that requirements engineering methodologies, a subset of systems engineering, should be taught and discusses the use of requirements engineering to derive software and hardware requirements for avionics subsystems. Definitions and applications of systems engineering methodologies to develop a technological product that succeeds from one milestone decision to another and from one life-cycle phase to the next are also covered. Finally, recommendations are made on how to better prepare pre-graduate engineers for such a workplace
Intrinsic therapeutic applications of noble metal nanoparticles: past, present and future

Biomedical nanotechnology is an evolving field having enormous potential to positively impact the health care system. Important biomedical applications of nanotechnology that may have potential clinical applications include targeted drug delivery, detection/diagnosis and imaging. Basic understanding of how nanomaterials, the building blocks of nanotechnology, interact with the cells and their biological consequences are beginning to evolve. Noble metal nanoparticles such as gold, silver and platinum are particularly interesting due to their size and shape dependent unique optoelectronic properties. These noble metal nanoparticles, particularly of gold, have elicited a lot of interest for important biomedical applications because of their ease of synthesis, characterization and surface functionalization. Furthermore, recent investigations are demonstrating another promising application of these nanomaterials as self-therapeutics. To realize the potential promise of these unique inorganic nanomaterials for future clinical translation, it is of utmost importance to understand a few critical parameters; (i) how these nanomaterials interact with the cells at the molecular level; (ii) how their biodistribution and pharmacokinetics influenced by their surface and routes of administration; (iii) mechanism of their detoxification and clearance and (iv) their therapeutic efficacy in appropriate disease model. Thus in this critical review, we will discuss the various clinical applications of gold, silver and platinum nanoparticles with relevance to above parameters. We will also mention various routes of synthesis of these noble metal nanoparticles. However, before we discuss present research, we will also look into the past. We need to understand the discoveries made before us in order to further our knowledge and technological development (318 references).
Improving resource efficiency in data centers using reputation-based resource selection ☆

Abstract Today data centers are consuming a lot of energy but not very efficiently. Much of energy is wasted. There are several types of energy waste at different levels including infrastructure-, machine- and system-level waste. The former two levels have been improved significantly in the last few years, however, few efforts have been put on the last level, especially the resource waste caused by failures in a data center. In this paper, we attack the problem proactively by leveraging a reputation-based resource selection scheme to reduce the number of resubmissions of tasks, resulting from the failure during the course of their execution. To capture the characteristics of resources, we introduce Opera, an OPEn ReputAtion model. Opera characterizes itself with two important novelties: a vector representation of the reputation and the just-in-time feature that represents the real-time system status, which, to our knowledge, has never been considered in conventional reputation systems. To demonstrate the effectiveness of Opera, we have integrated the Opera trust model into the scheduler of Hadoop. The experimental results showed that Opera enables the scheduler to select appropriate nodes which helped to reduce not only the number of re-executed tasks but also the execution time of Hadoop's jobs under the presence of failures and heavy workload up to 59% and 32%, respectively. This improvements, in turn, can improve the energy efficiency of the whole system and the network by 16.17% and 53.32% for the sort application respectively.
Neutron Star Interiors and Topology Change

Quark matter is believed to exist in the center of neutron stars. A combined model consisting of quark matter and ordinary matter is used to show that the extreme conditions existing in the center could result in a topology change, that is, in the formation of wormholes.
Hepatorenal syndrome. Studies of the effect of vascular volume and intraperitoneal pressure on renal and hepatic function

Eleven patients with well-documented hepatorenal syndrome were studied by measurement of blood volume, glomerular filtration rate, renal plasma flow, plasma aldosterone concentration, renin substrate concentration, and plasma renin activity. They were then given 750 ml of stored plasma, 750 ml of fresh frozen plasma, and then an infusion of angiotensin II, in random order on successive days. Infusion of fresh frozen plasma improved function more than did stored plasma and in addition returned a very low filtration fraction toward normal. Angiotensin II infusion increased filtration fraction, but decreased glomerular filtration rate, renal plasma flow, and urine flow sharply. Patients were then given a daily infusion of 1,000 ml of fresh frozen plasma for seven to 18 days to expand the blood volume to supranormal levels as assayed by serial measurement of blood volume. Plasma aldosterone levels decreased to a normal range, glomerular filtration rate and renal plasma flow both increased, and urinary excretion of sodium and potassium both returned toward normal. The effect of intraperitoneal pressure was then studied by measuring glomerular filtration rate, renal plasma flow, pressure in the vena cava, hepatic vein free flow, and hepatic vein wedged pressure before, during, and after paracentesis to reduce the intraperitoneal pressure from 30 to 40 cm H2O to 12 to 17 cm H2O. Venous pressures moved parallel to ascitic fluid pressures, and glomerular filtration rate, renal plasma flow, and urine flow all improved sharply; then, as ascitic fluid continued to form, reducing vascular volume, urine flow, glomerular filtration rate, and renal plasma flow all decreased slowly. Six patients then underwent placement of a LeVeen shunt. Improvement in glomerular filtration rate and renal plasma flow and clinical condition was dramatic. During postoperative observation of up to two years, progressive improvement in hepatic function has occurred.
The Thomas-Fermi Quark Model: Non-Relativistic Aspects

Abstract The first numerical investigation of non-relativistic aspects of the Thomas–Fermi (TF) statistical multi-quark model is given. We begin with a review of the traditional TF model without an explicit spin interaction and find that the spin splittings are too small in this approach. An explicit spin interaction is then introduced which entails the definition of a generalized spin “flavor”. We investigate baryonic states in this approach which can be described with two inequivalent wave functions; such states can however apply to multiple degenerate flavors. We find that the model requires a spatial separation of quark flavors, even if completely degenerate. Although the TF model is designed to investigate the possibility of many-quark states, we find surprisingly that it may be used to fit the low energy spectrum of almost all ground state octet and decuplet baryons. The charge radii of such states are determined and compared with lattice calculations and other models. The low energy fit obtained allows us to extrapolate to the six-quark doubly strange H -dibaryon state, flavor symmetric strange states of higher quark content and possible six quark nucleon–nucleon resonances. The emphasis here is on the systematics revealed in this approach. We view our model as a versatile and convenient tool for quickly assessing the characteristics of new, possibly bound, particle states of higher quark number content.
LIQUIDITY AND INEFFICIENT INVESTMENT

We study the role of fiscal policy in a complete markets model where the only friction is the nonpledgeability of human capital. We show that the competitive equilibrium is constrained inefficient, leading to too little risky investment. We also show that fiscal policy following a large negative shock can increase ex ante welfare. Finally, we show that if the government cannot commit to the promised level of fiscal intervention, the ex post optimal fiscal policy will be too small from an ex ante perspective.
Ranking suspected answers to natural language questions using predictive annotation

In this paper, we describe a system to rank suspected answers to natural language questions. We process both corpus and query using a new technique, predictive annotation, which augments phrases in texts with labels anticipating their being targets of certain kinds of questions. Given a natural language question, our IR system returns a set of matching passages, which we then rank using a linear function of seven predictor variables. We provide an evaluation of the techniques based on results from the TREC Q&A evaluation in which our system participated.
O‐tert‐Alkylformohydroximoyl Halides

We have prepared a series of the title compounds 4 and 5 from the corresponding formohydroxamates and found that they are remarkably inert, resembling vinyl halides rather than the sensitive N-alkylimidoyl halides. O-tert-Alkylformohydroximoylhalogenide Wir haben eine Reihe der Titelverbindungen 4 und 5 aus den entsprechenden Formohydroxamaten hergestellt und gefunden, das sie bemerkenswert inert sind und eher den Vinylhalogeniden ahneln als den empfindlichen N-Alkylimidoylhalogeniden.
Enveloping algebras of Hom-Lie algebras

Enveloping algebras of Hom-Lie and Hom-Leibniz algebras are constructed. 2000 MSC: 05C05, 17A30, 17A32, 17A50, 17B01, 17B35, 17D25 1
Evaporation from Porous Media in the Presence of a Water Table

Evaporation from porous media in the presence of a water table is influenced by the water table depth and the hydraulic characteristics of the medium, among other factors. For shallow water tables, the upward capillary liquid flow maintains continuous liquid pathways connecting the water table to the surface. For deeper water tables, however, the hydraulic continuity may be disrupted due to the opposing gravity and viscous forces. The main objective of this study was to demonstrate the limitation of the common assumption of liquid continuity through the unsaturated zone across large distances above a water table. The concept of the evaporation characteristic length was used to predict the maximum depth of the water table hydraulically connected to the surface. When the water table depth exceeded this characteristic length, the evaporative water loss was significantly suppressed due to the loss of liquid continuity. For model comparison, experimental data from the literature and data from laboratory evaporation experiments were used. Experimental results from cylindrical columns packed with sand with different particle size distributions connected to water tables fixed at various depths below the surface confirmed the existence of a finite characteristic length indicating the maximum depth of the water table hydraulically connected to the surface. The experimentally determined characteristic lengths were in a good agreement with the theoretical predictions. The obtained results also provided new insights regarding the solute transport and deposition patterns during evaporation in the presence of a water table.
Stress response inside perturbed particle assemblies

The effect of structural disorder on the stress response inside three dimensional particle assemblies is studied using computer simulations of frictionless sphere packings. Upon applying a localised, perturbative force within the packings, the resulting Green’s function response is mapped inside the different assemblies, thus providing an explicit view as to how the imposed perturbation is transmitted through the packing. In weakly disordered arrays, the resulting transmission of forces is of the double-peak variety, but with peak widths scaling linearly with distance from the source of the perturbation. This behaviour is consistent with an anisotropic elasticity response profile. Increasing the disorder distorts the response function until a single-peak response is obtained for fully disordered packings consistent with an isotropic description.
Selective sampling algorithms for cost-sensitive multiclass prediction

In this paper, we study the problem of active learning for cost-sensitive multiclass classification. We propose selective sampling algorithms, which process the data in a streaming fashion, querying only a subset of the labels. For these algorithms, we analyze the regret and label complexity when the labels are generated according to a generalized linear model. We establish that the gains of active learning over passive learning can range from none to exponentially large, based on a natural notion of margin. We also present a safety guarantee to guard against model mismatch. Numerical simulations show that our algorithms indeed obtain a low regret with a small number of queries.
Functionals for multilinear fractional embedding

A novel representation is developed as a measure for multilinear fractional embedding. Corresponding extensions are given for the Bourgain-Brezis-Mironescu theorem and Pitt’s inequality. New results are obtained for diagonal trace restriction on submanifolds as an application of the Hardy-Littlewood-Sobolev inequality. Smoothing estimates are used to provide new structural understanding for density functional theory, the Coulomb interaction energy and quantum mechanics of phase space. Intriguing connections are drawn that illustrate interplay among classical inequalities in Fourier analysis.
Analysis of elastic-plastic shells of revolution

A finite element approach using a displacement model is employed to analyze the behavior of elastic-plastic shells of revolution under axisymmetrical loading. The procedures developed are based on Kirchhoff hypotheses together with Love’s first approximation and small deflection theory. The method is quite general and is applicable to any shell geometry, loading, support conditions, and material properties, subject to the conditions of axial symmetry. The approach is suitable for routine computation on a digital computer. The examples shown are intended to show the reliability of the proposed approach, and not its versatility. The use of the proposed curved element proved to be very advantageous in requiring the use of relatively few elements to achieve good results. By applying the incremental technique together with the tangent stiffness method, it is possible to employ the flow theory of plasticity and to trace the loading history. The convergence of the method was found to be satisfactory.
Graduate education in ecological economics

Abstract Interest in graduate education in ecological economics is increasing. However, no formal plan of study for a PhD in ecological economics has been disseminated. The lack of a formal plan is problematic as the field of ecological economics matures, interest grows and new programs are being developed. This paper attempts to fill a void by creating a program of study addressing the proficiencies a graduate student in ecological economics should have upon completion of his/her PhD based on the US educational system. The plan of study presented in this paper has been developed to make the graduate of an ecological economics program as competitive on the labor market as students awarded traditional economics degrees. The plan I describe is created to meet the requirements necessary for a PhD in ecological economics. Further, fields of specialization are suggested to complement the core of an ecological economics program, to enhance the education process and to give the student with an ecological economics degree a higher level of marketability.
Spectrum auction framework for access allocation in cognitive radio networks

In cognitive radio networks, there are two categories of networks on different channels: primary networks, which have high-priority access, and secondary networks, which have low-priority access. We develop an auction-based framework that allows networks to bid for primary and secondary access based on their utilities and traffic demands. The bids are used to solve the access allocation problem, which is that of selecting the primary and secondary networks on each channel either to maximize the auctioneer's revenue or to maximize the social welfare of the bidding networks, while enforcing incentive compatibility. We first consider the case when the bids of a network depend on which other networks it will share channels with. When there is only one secondary network on each channel, we design an optimal polynomial-time algorithm for the access allocation problem based on reduction to a maximum matching problem in weighted graphs. When there can be two or more secondary networks on a channel, we show that the optimal access allocation problem is NP-complete. Next, we consider the case when the bids of a network are independent of which other networks it will share channels with. We design a polynomial-time dynamic programming algorithm to optimally solve the access allocation problem when the number of possible cardinalities of the set of secondary networks on a channel is upper-bounded. Finally, we design a polynomial-time algorithm that approximates the access allocation problem within a factor of 2 when the above upper bound does not exist.
Preoperative sonographic radial artery evaluation and correlation with subsequent radiocephalic fistula outcome.

Objective. Primary failure of forearm radiocephalic dialysis fistulas is common even when preoperative vascular mapping is used. Previous studies have suggested that low peak systolic velocity of the radial artery predicts subsequent fistula failure. The study goal was to evaluate whether preoperative spectral Doppler assessment of radial artery inflow can improve forearm fistula outcome prediction. Methods. Forearm fistulas were placed in 112 patients after preoperative sonographic mapping. Preoperative spectral Doppler sonography measured radial artery peak systolic velocity during tight fist clenching for 3 minutes and after fist relaxation. Vessel diameters and peak systolic velocity were assessed for predictive value based on subsequent fistula adequacy. Fistula flow rates were determined 6 to 12 weeks postoperatively in a subset of patients. Results. Failed and successful fistulas were similar in their preoperative arterial and vein diameters, resistive index, and peak systolic velocity during fist clenching and after fist relaxation. Specifically, there was no difference in fistula success with radial artery peak systolic velocity lower than 50 cm/s versus peak systolic velocity of 50 cm/s or higher. The change in peak systolic velocity after fist relaxation was highly predictive of subsequent fistula outcome among female patients in ad hoc analysis. Fistula adequacy for dialysis in women was 11% when the change in peak systolic velocity was lower than 0 cm/s and 50% when the change was 0 cm/sec or higher (P = .02). The postoperative fistula flow rates were lower when the preoperative change in peak systolic velocity was lower than 0 cm/s than when it was 0 cm/s or higher (316 ± 46 versus 781 ± 150 mL/min; P = .003). Conclusions. There was no difference in the preoperative peak systolic velocity or the resistive index of successful and failed fistulas. Measurement of the radial artery peak systolic velocity change after release of fist clenching was not useful in predicting outcomes in male patients but identified a subset of female patients with a very low likelihood of success. This criterion may merit further investigation in future trials.
Cross-Border Listings and Price Discovery: Evidence from U.S.-Listed Canadian Stocks

We examine the contribution of cross-listings to price discovery for a sample of Canadian stocks listed on both the Toronto Stock Exchange (TSE) and a U.S. exchange. We ¢nd that priceson the TSE and U.S. exchange are cointegrated and mutually adjusting. The U.S. share of price discovery ranges from 0.2 percent to 98.2 percent, with an average of 38.1 percent. The U.S. share is directly related to the U.S. share of trading and to the ratio of proportions of informative tradeson the U.S. exchange and the TSE, and inversely related to the ratio of bid-ask spreads. WITH THE ENHANCED GLOBALIZATION of ¢nancial markets, the number of non-U.S. ¢rms cross-listing shares on a U.S. exchange has substantially increased. Attracting non-U.S. listings is now a top priority of the U.S. stock exchanges. At the end of 2000, 420 non-U.S. ¢rmswere listed on the New York Stock Exchange (NYSE).The number of foreign ¢rmslisted on Nasdaq waseven higher.The popularity of international cross-listings has prompted many academic studies on the topic. 1 Most of these studies focus on the bene¢ts of international cross-listings, including the reduced cost of capital and the enhanced liquidity of a ¢rm’s stock. Studiessuch asAlexander, Eun, and Janakiramanan (1987, 1988) and Foerster and Karolyi (1993) suggest that the cost of capital declines because the portion of the risk premium that compensates for cross-border investment barriers dissipates. Miller (1999) and Foerster and Karolyi (1999) propose increased investor recognition as another possible explanation. Several studies examine changes in trading volume and costs due to international cross-listing. Foerster and Karolyi (1998) ¢nd that the bid-ask spreads in Canada decrease after the cross-listing of Canadian stocks in the United States. Domowitz, Glen, and Madhavan (1998) suggest that the impact of cross-listing is complex and depends on the degree of quote transparency, that is, the extent to which price information is observable in the two markets. Smith and So¢anos (1997) examine if cross-listing is a zerosum game, with increased trading in the United States being oiset by reduced
CONTRACEPTION AS DEVELOPMENT? NEW EVIDENCE FROM FAMILY PLANNING IN COLOMBIA

There has been considerable debate in the last decade about whether or not family planning programmes in developing countries reduce fertility or improve socio-economic outcomes. This article provides new evidence by studying the expansion of one of the worlds oldest and largest family planning organisations -- Profamilia of Colombia. It finds that family planning explains less than 10% of Colombias fertility decline during its demographic transition. As in wealthy countries however lowering the costs of first birth postponement produced important socio-economic gains enabling young women to obtain more education and to work more and live independently later in life.
Structural characterization of [VO(salicylhydroximate)(CH3OH)]3: Applications to the biological chemistry of vanadium(V)

The biological chemistry of vanadium has garnered increased attention due to the recent isolation of vanadium enzymes capable of nitrogenase [l] and bromoperoxidase [2,3] activities. The latter enzymes, isolated from marine algae, contain a mononuclear V(V) active site [4] that does not appear to require redox chemistry in the catalytic mechanism. It is well established that bacteria and algae often produce low molecular weight chelating agents (siderophores) which will sequester metal ions and facilitate the transport of these nutrients into the cell [5]. The two major classes of siderophores are based on catecholate and hydroxamate metal ligands [6]. Because vanadium bromoperoxidase is isolated from algae and bacteria, we felt that it would be interesting to examine the coordination chemistry of vanadium with hydroxamate ligands that might form the basis of vanadium sequestering agents for these organisms. In the process of our studies, we have isolated an intriguing trinuclear cluster composed of V03+ and salicylhydroxamic acid and report herein the structure and solution chemistry of this molecule. [VO(salicylhydroximate)(CHsOH)] a (1) can be prepared in 70% yield by the room temperature reaction of one equivalent of VO(acetylacetonate)z or VCla with salicylhydroxamic acid and three equivalents of NaOCHs or NaOH in methanol. Air acts as the oxidant to form deep blue solutions of 1. Slow evaporation of a methanol solution gave deep blue blocks which were suitable for X-ray crystallographic analysis. Crystallographic data for 1: monoclinic, space group P2Jc, a = 11.006(3), b = 15.722(7), c = 2 1.240(6) A; fi = 111.40(2)‘; v = 3422(2) A3, Z = 4; l(Mo Kor) =0.7107 A; crystal dimensions 0.42 X 0.49 X 0.52 mm3; p = 8.19 cm-l. The intensities of 4504 reflections were measured at room temperature (0 G26 < 453 on a P2r diffractometer using MO Ka radiation. The structure was solved using the SHELX-86 program. All nonhydrogen atoms were refined using anisotropic thermal parameters. Hydrogen atoms were located, but not refined, and placed at fixed distances (0.95 A) from bonded carbon atoms. All calculations were carried out using the SHELX-86 program. For Fig. 1. An ORTEP diagram of 1 with thermal ellipsoids at 30% probability. Selected mean bond lengths (A) and angles (“) for chemically equivalent bonds with range in parentheses: V=O, 1.59 (1.582-1.602); V-O,, 1.85 (1.8421.861); v-o,, 2.08 (2.061-2.096); V-O,., 2.12 (2.0902.143); V-On, 1.86 (1.858-1.868); V-N, 2.02 (2.0142.030); On-N, 1.37 (1.362-1.376); Cn-N, 1.33 (1.3181.339); Cn-0, 1.26 (1.260-1.275); V-V, 4.66 (4.6524.671); O=V-0,, 91 (88.1-92.7); O=V-O,, 108 (107.5108.6); O=V-On, 94 (93.8-94.7); O=V-N, 98 (97.098.1); O=V-0,, 165 (163.1-166.7); V-N-On, 120 (119.5-120.6); N-0,-V, 120 (119.4-120.2).
A web-based resource for investigating environmental change: The emigrant pass observatory

ABSTRACT We present a user-friendly, data-driven Web site (http://thermal.gg.utah.edu/facilities/epo/) for a geothermal, climate change observatory that is educational for the general public, students, and researchers alike. The Emigrant Pass Observatory (EPO), located in the Grouse Creek Mountains in northwestern Utah, gathers both meteorological data (solar radiation, air temperature, rainfall, wind speed and direction, and snow depth) and subsurface temperatures in shallow drillholes. Our website has three main functions: (1) it provides a tutorial for understanding both local climate and climate change, and their relation to diffusion of temperatures into the Earth's subsurface; (2) it facilitates user-defined accessibility to download available climate data; and (3) it contains lesson ideas for using real data to understand local climate. EPO data and resources are ideal for active learning projects. Additionally, our collaboration with ongoing outreach projects (e.g., NSF-sponsored GK–12) in Utah pr...