cssi/SciSciGPT-SciSciNet huggingface dataset:
Partial Factor Productivity, Agronomic Efficiency, and Economic Analyses of Maize in Wheat-Maize Cropping System in Pakistan

Getting maximum benefits from cereals do not lie in reducing N-rate and its number of splits but lowering cost per unit cereal production through higher yields. Field experiments were conducted on maize (Zea mays L.) at the New Developmental research Farm of NWFP (Northwest Frontier Province) Agricultural University Peshawar-Pakistan during 2002-03 and 2003-04 in order to investigate effects of variable rates of N and its time of application on the partial factor productivity (PFPN), agronomic efficiency (AEN), net returns (NR), value-cost ratio (VCR) and marginal returns (MR). The 2 x 3 x 6 factorial experiment was designed having two plant densities (D1 = 60,000 and D2 = 100,000 plants ha-1) and three N levels (N1 = 60, N2 = 120 and N3 = 180 kg N ha-1) applied to main plots, while six split application of N in different proportions were applied to subplots in two equal (T1), three equal (T2), three unequal (T3), four equal (T4), five equal (T5) and five unequal splits (T6) at sowing and with 1st, 2nd, 3rd and 4th irrigation at two wk intervals. Maize ranked first with maximum PFPN, AEN, NR, VCR and MR at higher than at lower plant density, and the increase in all these parameters studied in the experiments was more in 2003-04 as compared to 2002-03. Both PFPN and AEN showed negative relationship with increase in N rates and the cast that vary, but NR, VCR and MR showed positive relationship with increase in N rates and the cost that vary. Among time of N application, maximum PFPN, AEN, NR, VCR and MR were calculated when N was applied in five equal splits (T5) almost comparable with T4 and T6 but was more economical when compared with T1, T2, and T3. In conclusion, the findings suggest that growing maize at D2 applied with N3 in four to five splits is more economical in the wheat-maize cropping system of NWFP.
Using Enrollment Discontinuities to Estimate the Effect of Voluntary Conservation On Local Land Values

O ering payments in exchange for voluntary land use restrictions is an increasingly popularway of conserving ecosystem services such as wildlife habitat, air and water quality enhance-ments, and carbon sequestration on agricultural land. The Conservation Reserve Programis the largest U.S. federal program of this kind. It currently enrolls over 34 million acres ofproductive cropland (about the size of Iowa), paying enrolled landowners over $1.8 billionfor contracts active in 2008.Besides the direct e ects of conservation activities in exchange for money, there may bespillovers stemming from voluntary conservation programs. For large-scale programs likeCRP, some argue that conservation activities reduce local demand for agricultural labor, in-puts and services, thereby causing local economic decline - i.e., negative economic spillovers.To date, evidence of such spillover e ects, even in areas where a signi cant share of thelocal cropland is enrolled in CRP, suggests these e ects are minimal (Sullivan et al. 2004).This evidence shows that overall trends in employment and population, even in areas withlarge CRP enrollments, were unperturbed around the time of those enrollments, and similarto patterns in otherwise similar areas with little or no CRP enrollment. Other anecdotalevidence suggests CRP enrollments have enhanced recreation opportunities, particularly forhunting and for bird watching. Thus, it could be that negative spillovers on agricultural eco-nomic activities are o set by positive spillovers in other sectors of rural economies. Finally,CRP enrollment could have far reaching economic e ects through commodity prices. CRPcontracts have removed 10 percent of the productive cropland in the United States, repre-senting a signi cant downward shift in the supply of cropland acreage and thereby increasingcrop prices.In this paper we examine the e ect of CRP on agricultural land values, including possiblee ects from local economic spillovers. Asset pricing theory predicts that land prices willembody present and future returns to land, and therefore should capture direct and at leastsome indirect e ects of CRP. For example, if payments for conservation activities generallyexceed the amount farmers would have been willing to accept, this could cause an increase inland value for farmers able to gain enrollment. Alternatively, if CRP caused a reduction inthe supply of inputs and labor for non-participating farmers, it could cause their land valuesto decline. CRP might also enhance bird and wildlife populations and thereby increasedemand for recreational services, which could cause land values to increase, perhaps evenfor non-participating landlords. One potentially useful aspect of land values in comparisonto other outcomes is that they embody speculation about broader e ects even before those1
Pattern Classfication in Dynamical Environments: Tagged Feature-Class Space and Univariate Sequential Classifier

This paper presents a statistic pattern recognition and machine learning based classification system paradigm. It focuses on solving problems underlying environments where the attributes of the system exhibit strong uncertainties. Configurations of classifiers therefore have to undergo continual changes during the running process. The classifier discussed here is characterized by a tagged feature-class representation, a dimension-wise univariate discrimination scheme, a default hierarchy of classification, as well as a logic-based learning strategy. Concepts of distinguishability and univariately distinguishable classes under classification are studied. Procedures developed for forming an univariately distinguishable class-feature space by learning are described.
The Gramm-Leach-Bliley Act

In the fall of 1999, President Clinton signed into law the Gramm-Leach-Bliley Act, also known as the Financial Services Modernization Act. Twenty years later, this statute still governs how financial institutions use consumer data. The statute represents the first (and only) federal law that gives consumers privacy protection over nonpublic personally identifiable information. This paper examines a number of GLBA provisions and demonstrates that consumers do not control the terms under which their financial information is used. While the GLBA was an important first step in obtaining some level of information privacy, this paper argues that Congress undoubtedly placed a much higher value on data use than on data protection.
An Immersive Virtual Reality Mock-Up for Design Review of Hospital Patient Rooms

Full scale physical mock-ups of specific hospital units such as patient rooms are routinely utilized to serve the multiple purposes of constructors, designers, and owner stakeholders for healthcare facility projects. The shortcoming with this practice is that the mock-up is constructed during the construction phase and is of limited use for making extensive decisions regarding the functionality of the room design. Three-dimensional visualisation tools offer healthcare facility stakeholders the opportunity to comprehend proposed designs more clearly during the planning and design phases, thus enabling the greatest influence on design decision making. While several options exist, based on their experience with a bariatric patient room model, the authors promote the utilization of Virtual Reality mock-ups for design review because of their enhanced capacity for an immersive, interactive experience with the design and for the long-term utility of such models for the balance of the project life cycle.
YEAST AS A SOURCE OF VITAMINE B FOR THE GROWTH OF RATS

Yeast is commonly considered the richest source of vitamine-B for the growth of young animals. We have fed groups of rats in colonies on a basal diet of purified casein 18 per cent., salts 3.7 per cent., agar 2 per cent., butter fat 5 per cent., with dextrin to make 100 per cent., and have supplied the vitamine-B in the form of dried yeast of various sources, both as an integral part of the diet or separately in the form of a tablet. Our results were as follows:Air-dried Fleischmann's baker's yeast containing 40 per cent. yeast in the dried product failed to produce normal growth in all cases when the ration contained 4 per cent. or less of the dried product and certain individuals even failed to make normal growth when the dried yeast formed 10 per cent. of the diet. Out of 20 rats, 9 were females, and none of these produced young during the 2 to 4 months of the experiment.When the same yeast was fed separately, 0.6 gram per day per rat was required to secure normal growth. Two out of 4 females on this d...
Causality, responsibility, and blame: a structural-model approach

This talk will provide an overview of work that I have done with Hana Chockler and Judea Pearl [1,4,5] on defining notions such as causality, explanation, responsibility, and blame. I first review the Halpern-Pearl definition of causality-what it means that A is a cause of B–and show how it handles well some standard problems of causality. This definition is based on what are called structural equations, which are ways of describing the effects of interventions. The definition (like most in the literature) views causality as an all-or-nothing concept. Either A is a cause of B or it is not. I show how the account can be extended to take into account the degree of responsibility of A for B. For example, if someone wins an election 11-0, each person is less responsible for his victory than if he had won 6-5. Finally, I discuss more recent work [2,3] on combining a theory of normality (or defaults) with the structural equations. A slightly revised definition of causality that uses normality deals well with problems that have been pointed out in the original Halpern-Pearl definition, and helps explain different intuitions that people have regarding causality.
A Comparison of Quality of Life Measures in Husbands of Women with Breast Cancer

The Quality of Well-Being Scale (QWB-SA) and Medical Outcome Study SF-36 short form (SF-36) are popular health-related quality of life (HRQOL) assessment tools; however, it is unclear whether these measures overlap enough to be interchangeable, and if not, which might be a better choice. This study examined conceptual overlap, validity, and relation with psychosocial functioning of the QWB-SA and SF-36 in a sample of partners of women undergoing adjuvant treatment for breast cancer. Partners (n = 79) of breast cancer patients, recruited in a chemotherapy infusion clinic, completed the QWB-SA and SF-36 and additional psychosocial measures. Descriptive content review shows that both instruments provide a breadth of HRQOL coverage including physical health, mental health, social functioning, role functioning and general health perceptions; however, more QWB-SA scales suffered floor effects. Subscales correlated, with the strongest correlations between the QWB-SA total score and the mental health scales of the SF-36. The QWB-SA and the SF-36 Mental Health Component Summary score, but not the SF-36 Physical Component Summary score were strongly correlated to measures of mood, satisfaction with life, burden, and social support. The QWB-SA and SF-36 measure distinct aspects of HRQOL. Each instrument presents distinct advantages and disadvantages in coverage of particular domains. Labels assigned to SF-36 scales more accurately reflect what they measure. The SF-36 appeared more sensitive to the impact that psychological health played on overall assessment of HRQOL in these partners.
Applicability of generic naming services and fault-tolerant metacomputing with FT-MPI

There is a growing interest in deploying MPI over multiple, heterogenous and geographically distributed resources for performing very large scale computations. However, increasing the amount of geographical distribution and resources creates problems with interoperability and fault-tolerance. FT-MPI presents an interesting solution for adding fault-tolerance to MPI, but suffers from interoperability limitations and potential single points of failure when crossing multiple administrative domains. We propose to overcome these limitations by adding “pluggability” for one potential single point of failure – the name service used by FT-MPI – and combining FT-MPI with the H2O metacomputing framework.
Private bills: A theoretical and empirical study of lobbying ∗

Interest groups lobby over a variety of issues includingprivate bills. There are two striking facts about privatebills introduced in the U.S. Congress. First, several scandalshave involved Congressmen who were being bribed to introduce aprivate bill. Second, the number of private bills introducedhas drastically changed over time. A theoretical model and aneconometric model are developed to explain these phenomena.
Congressional Voting on Term Limits

Between 1990 and 1995,twenty-three states unilaterally imposedterm limits on their own delegations toCongress. In 1995 the House ofRepresentatives defeated a constitutionalamendment that would have limited the termsfor all of Congress. Only weeks later, theSupreme Court struck down the individualstate laws. In 1997 the House againbrought the issue to a vote, which alsofailed. This paper models congressionalvoting on term limits with a simple gamewithin an interest-group theory withlegislators as imperfect agents ofconstituents. The game foremost predictsthat members from term-limited states wouldbe more likely to support term limits inthe first vote but no more likely on thesecond vote. The empirical section employsprobit, multinomial logit, and orderedprobit maximum likelihood estimations toconfirm the stated hypotheses. Among otherresults, in particular both the joint andconditional probability of a `yea' on thefirst vote and a subsequent `nay' on thesecond vote is higher for members fromstates that had unilaterally self-imposedterm limits. The results are robust tomodel specification, estimator, andalternative sampling. Implications areproposed in the concluding comments.
The 1996 One Percent Initiative in Idaho

The 1996 One Percent Initiative in Idaho would have limited property tax rates and the local government expenditures while shifting public school funding to the state. This study shows that Idaho’s property tax is unfair and that the proponents tried to use the voters dissatisfaction to reduce government spending.
The role of reinsurance in state efforts to expand coverage.

Recently, some states have revisited the concept of reinsurance to spread risk in insurance markets, improve the predictability of claims, and reduce the markup of premiums that insurers charge as a buffer against unanticipated claims. This brief examines efforts in Arizona, Connecticut, Idaho, Massachusetts, New Mexico, and New York and proposes lessons for states considering reinsurance programs to expand small group or individual coverage. The author concludes that, while it is unlikely that a state-level reinsurance program will solve the complex problem of making coverage affordable and accessible to all, it can be an efficient strategy for stabilizing coverage and perhaps expanding it.
A Simple Linear Time Algorithm for Proper Box Rectangular Drawings of Plane Graphs

In this paper we introduce a new drawing style of a plane graph G, called proper box rectangular (PBR) drawing. It is defined to be a drawing of G such that every vertex is drawn as a rectangle, called a box, each edge is drawn as either a horizontal or a vertical line segment, and each face is drawn as a rectangle. We establish necessary and sufficient conditions for G to have a PBR drawing. We also give a simple linear time algorithm for finding such drawings. The PBR drawing is closely related to the box rectangular (BR) drawing defined by Rahman, Nakano and Nishizeki [17]. Our method can be adapted to provide a new algorithm for solving the BR drawing problem.
Measuring the Relative Profitability of Mid-South Cotton Production from an Alternative Gin Seed Rebate Model

The purpose of this paper is to assess the opportunity returns forgone to cotton producers in the lower Mid-South region of the United States for growing cotton, compared to alternative commodities. We calculate the actual net returns per acre for selected cotton-producing counties in Arkansas, Louisiana, and Mississippi. In addition, we calculate the opportunity returns per acre if the acres planted in cotton were planted in the highest net return commodity per acre between corn and soybeans during the period 1997 through 2008. Our results find that producers in these cotton producing-counties faced sizeable opportunity revenues foregone averaging 43% between 2003 and 2008. Most observers of the cotton industry would argue that these foregone revenues are a function of historical cotton producers not planting a higher proportion of their acreage in the more-profitable corn enterprise in 2007 and 2008. However, opportunity revenues per acre foregone averaged 37% in the 2007-08 period. This finding suggests that cotton producers recognized a few years prior to the corn price spike in 2007 that alternative commodities, such as corn and soybeans, would generate greater returns on their land. Our research suggests that the higher corn price helped push cotton producers over the edge into planting a greater percentage of their acreage in alternative commodities.
Measuring the magnitude of sums of independent random variables

This paper considers how to measure the magnitude of the sum of independent random variables in several ways. We give a formula for the tail distribution for sequences that satisfy the so called Levy property. We then give a connection between the tail distribution and the pth moment, and between the pth moment and the rearrangement invariant norms.
Detection of Nuclear X-Ray Sources in Nearby Galaxies with Chandra

We report preliminary results from an arcsecond-resolution X-ray survey of nearby galaxies using the Advanced CCD Imaging Spectrometer on board the Chandra X-Ray Observatory. The total sample consists of 41 low-luminosity active galactic nuclei (AGNs), including Seyfert galaxies, LINERs, and LINER/H II transition objects. In the initial subsample of 24 objects observed thus far, we detect in ~62% of the objects a compact, pointlike source astrometrically coincident with either the optical or radio position of the nucleus. The high detection rate strongly suggests that the majority of the objects do contain weakly active, AGN-like cores, presumably powered by central massive black holes. The 2-10 keV luminosities of the nuclear sources range from less than 1038 to 1041 ergs s-1, with a median value of 2 × 1038 ergs s-1. Our detection limit corresponds to LX(2-10 keV) ≈ 8 × 1037 ergs s-1 for the typical sample distance of 12 Mpc; this limit is 2 orders of magnitude fainter than the weakest sources of this kind previously studied using ASCA or BeppoSAX. The new data extend toward lower luminosities the known linear correlation between hard X-ray and Hα luminosity for broad-line AGNs. Many narrow-line objects do contain X-ray cores, consistent with either weak AGNs or X-ray binary systems, but they have X-ray luminosities a factor of 10 below the LX-LHα relation of the broad-line sources. Their distributions of photon energies show no indication of exceptionally high absorption. The optical line emission in these nuclei is likely powered, at least in part, by stellar processes.
Extra-dimensional Island-Style FPGAs

This paper proposes modifications to standard island-style FPGAs that provide interconnect capable of scaling at the same rate as typical netlists, unlike traditionally tiled FPGAs. The proposal uses a logical third and fourth dimensions to create increasing wire density for increasing logic capacity. The additional dimensions are mapped to standard two-dimensional silicon. This innovation will increase the longevity of a given cell architecture, and reduce the cost of hardware, CAD tool and Intellectual Property (IP) redesign. In addition, extra-dimensional FPGA architectures provide a conceptual unification of standard FPGAs and time-multiplexed FPGAs.
GraphAEL: Graph Animations with Evolving Layouts

GraphAEL extracts three types of evolving graphs from the Graph Drawing literature and creates 2D and 3D animations of the evolutions. We study citation graphs, topic graphs, and collaboration graphs. We also create difference graphs which capture the nature of change between two given time periods. GraphAEL can be accessed online at http://graphael.cs.arizona.edu.
Finding Minors in Graphs with a Given Path Structure

Given graphs G and H with VHi¾?VG, suppose that we have a u,v-path Puv in G for each edge uv in H. There are obvious additional conditions that ensure that G contains H as a rooted subgraph, subdivision, or immersion; we seek conditions that ensure that G contains H as a rooted minor or minor. This naturally leads to studying sets of paths that form an H-immersion, with the additional property that paths that contain the same vertex must have a common endpoint. We say that H is contractible if, whenever G contains such an H-immersion, G must also contain a rooted H-minor. We show, for example, that forests, cycles, K4, and K1, 1, 3 are contractible, but that graphs that are not 6-colorable and graphs that contain certain subdivisions of K2, 3 are not contractible.
Selective view materialization in a spatial data warehouse

A spatial data warehouse (SDW) consists of a set of materialized views defined over the source relations, either conventional, spatial, or both. Often, when compared to the traditional data warehouses, the cost of view materialization is more expensive with respect to both computation and space. This is because the spatial data is typically larger in size, which leads to high maintenance cost, and the spatial operations are more expensive to process. In this paper, we address the issue of optimizing the view materialization cost in an SDW. We build a cost model to measure the on-the-fly computation cost versus the space cost for spatial queries. We show that a spatial query can be represented in the form of the query-graph and propose three transformation rules, edge-elimination, query-splitting and query-joining, to selectively materialize spatial views. We present a greedy algorithm for materialized view selection so that the local cost optimality can be achieved.
Mining of MicroRNA expression data—a rough set approach

In our research we used a microRNA expression level data set describing eleven types of human cancers. Our methodology was based on data mining (rule induction) using rough set theory. We used a novel methodology based on rule generations and cumulative rule sets. The original testing data set described only four types of cancer. We further restricted our attention to two types of cancer: breast and ovary. Using our combined rule set, all but one cases of breast cancer and all cases of ovary cancer were correctly classified
Equivalences of logic programs

For applications such as deductive databases employing the Open World Assumption, failed derivations have a lesser importance. In this case, use of the identical equivalences based upon the functional semantics [P] and the logical consequences of P allows the application of two different and powerful tools to reason about programs. In particular, these equivalences seem ideal for discussing the deductive structure of such deductive databases, independent of any particular state of the database of facts.
Traces on algebras of parameter dependent pseudodifferential operators and the eta–invariant

We identify Melrose's suspended algebra of pseudodifferential operators with a subalgebra of the algebra of parametric pseudodifferential operators with parameter space $\R$. For a general algebra of parametric pseudodifferential operators, where the parameter space may now be a cone $\Gamma\subset\R^p$, we construct a unique ``symbol valued trace'', which extends the $L^2$-trace on operators of small order. This allows to construct various trace functionals in a systematic way. Furthermore we study the higher-dimensional eta-invariants on algebras with parameter space $\R^{2k-1}$. Using Clifford representations we construct for each first order elliptic differential operator a natural family of parametric pseudodifferential operators over $\R^{2k-1}$. The eta-invariant of this family coincides with the spectral eta-invariant of the operator.
Interpreting Permanent Shocks to Output When Aggregate Demand May Not Be Neutral in the Long Run

This paper studies a popular statistical model of permanent and transitory shocks to output using a set of arguably more plausible structural assumptions. One way to structurally interpret the model is by assuming aggregate demand has no long-run output effect. However, many economic theories are inconsistent with that assumption. Instead, we reinterpret the statistical model assuming a positive shock to aggregate supply lowers the price level and in the long run raises output while a positive shock to aggregate demand raises the price level. Under these assumptions, a puzzling finding from the empirical literature implies that a positive aggregate demand shock had a long-run positive effect on output in pre–World War I economies.
Clinical, Pathological, and Surgical Outcomes for Adult Pineoblastomas

Introduction Pineoblastomas are uncommon primitive neuroectodermal tumors that occur mostly in children; they are exceedingly rare in adults. Few published reports have compared the various aspects of these tumors between adults and children. Methods The authors report a series of 12 pineoblastomas in adults from 2 institutions over 24 years. The clinical, radiologic, and pathologic features and clinical outcomes were compared with previously reported cases in children and adults. Results Patient age ranged from 24 to 81 years, and all but 1 patient exhibited symptoms of obstructive hydrocephalus. Three patients underwent gross total resection, and subtotal resection was performed in 3 patients. Diagnostic biopsy specimens were obtained in an additional 6 patients. Pathologically, the tumors had the classical morphologic and immunohistochemical features of pineoblastomas. Postoperatively, 10 patients received radiotherapy, and 5 patients received chemotherapy. Compared with previously reported cases, several differences were noted in clinical outcomes. Of the 12 patients, only 5 (42%) died of their disease (average length of survival, 118 months); 5 patients (42%) are alive with no evidence of disease (average length of follow-up, 92 months). One patient died of unrelated causes, and one was lost to follow-up. Patients with subtotal resections or diagnostic biopsies did not suffer a worse prognosis. Of the 9 patients with biopsy or subtotal resection, 4 are alive, 4 died of their disease, and 1 died of an unrelated hemorrhagic cerebral infarction. Conclusions Although this series is small, the data suggest that pineoblastomas in adults have a less aggressive clinical course than in children.
Going with the flow: using gas clouds to probe the accretion flow feeding Sgr A*

The massive black hole in our galactic center, Sgr A*, accretes only a small fraction of the gas available at its Bondi radius. The physical processes determining this accretion rate remain unknown, partly due to a lack of observational constraints on the gas at distances between ~10 and ~10$^5$ Schwarzschild radii (Rs) from the black hole. Recent infrared observations identify low-mass gas clouds, G1 and G2, moving on highly eccentric, nearly co-planar orbits through the accretion flow around Sgr A*. Although it is not yet clear whether these objects contain embedded stars, their extended gaseous envelopes evolve independently as gas clouds. In this paper we attempt to use these gas clouds to constrain the properties of the accretion flow at ~10$^3$ Rs. Assuming that G1 and G2 follow the same trajectory, we model the small differences in their orbital parameters as evolution resulting from interaction with the background flow. We find evolution consistent with the G-clouds originating in the clockwise disk. Our analysis enables the first unique determination of the rotation axis of the accretion flow: we localize the rotation axis to within 20 degrees, finding an orientation consistent with the parsec-scale jet identified in x-ray observations and with the circumnuclear disk, a massive torus of molecular gas ~1.5 pc from Sgr A*. This suggests that the gas in the accretion flow comes predominantly from the circumnuclear disk, rather than the winds of stars in the young clockwise disk. This result will be tested by the Event Horizon Telescope within the next year. Our model also makes testable predictions for the orbital evolution of G1 and G2, falsifiable on a 5-10 year timescale.
Testing geometric convexity

We consider the problem of determining whether a given set S in ${\mathbb R}^{n}$ is approximately convex, i.e., if there is a convex set $K \in {\mathbb R}^{n}$ such that the volume of their symmetric difference is at most e vol(S) for some given e. When the set is presented only by a membership oracle and a random oracle, we show that the problem can be solved with high probability using poly(n)(c/e)n oracle calls and computation time. We complement this result with an exponential lower bound for the natural algorithm that tests convexity along “random” lines. We conjecture that a simple 2-dimensional version of this algorithm has polynomial complexity.
Botswana's infrastructure : a continental perspective

Infrastructure made a net contribution of just over two percentage points to Botswana's improved per capita growth performance in recent years. Raising the countrys infrastructure endowment to that of the region's middle-income countries could boost annual growth by about 1.2 percentage points. Botswana has made significant infrastructure progress in recent years, spanning the transport, water and sanitation, power, and mobile telephony sectors. But the country still faces a number of important infrastructure challenges. The most pressing is in the power sector, where the country is economically and financially exposed to a lack of generation capacity and insufficient power supply, leaving the economy vulnerable to power price shocks and load shedding. Botswana's international transport connections and Internet connectivity also lag behind those of comparable countries. Botswana's overall resource envelope of $800 million per year surpasses its $785 million needs estimate. Nevertheless, it loses $68 million a year to inefficiencies and faces a funding gap of $305 million per year, entirely in the power sector, traceable to the quality of spending decisions. Botswana will be in a good position to meet its infrastructure goals if it can reduce inefficiencies, increase public-sector receipts, and attract more public funding.
Quantization using compressive sensing

The problem of compressing a real-valued sparse source using compressive sensing techniques is studied. The rate distortion optimality of a coding scheme in which compressively sensed signals are quantized and then reconstructed is established when the reconstruction is also required to be sparse. The result holds in general when the distortion constraint is on the expected p-norm of error between the source and the reconstruction. A new restricted isometry like property is introduced for this purpose and the existence of matrices that satisfy this property is shown.
An Error Correcting Parser for Context Free Grammars that Takes Less Than Cubic Time

The problem of parsing has been studied extensively for various formal grammars. Given an input string and a grammar, the parsing problem is to check if the input string belongs to the language generated by the grammar. A closely related problem of great importance is one where the input are a string \(\mathcal{I}\) and a grammar G and the task is to produce a string \(\mathcal{I}'\) that belongs to the language generated by G and the ‘distance’ between \(\mathcal{I}\) and \(\mathcal{I}'\) is the smallest (from among all the strings in the language). Specifically, if \(\mathcal{I}\) is in the language generated by G, then the output should be \(\mathcal{I}\). Any parser that solves this version of the problem is called an error correcting parser. In 1972 Aho and Peterson presented a cubic time error correcting parser for context free grammars. Since then this asymptotic time bound has not been improved under the assumption that the grammar size is a constant. In this paper we present an error correcting parser for context free grammars that runs in O(T(n)) time, where n is the length of the input string and T(n) is the time needed to compute the tropical product of two \(n\times n\) matrices.
How to complete a doubling metric

In recent years, considerable advances have been made in the study of properties of metric spaces in terms of their doubling dimension. This line of research has not only enhanced our understanding of finite metrics, but has also resulted in many algorithmic applications. However, we still do not understand the interaction between various graphtheoretic (topological) properties of graphs, and the doubling (geometric) properties of the shortest-path metrics induced by them. For instance, the following natural question suggests itself: given a finite doubling metric (V, d), is there always an unweighted graph (V′,E′) with V ⊆ V′ such that the shortest path metric d′ on V′ is still doubling, and which agrees with d on V. This is often useful, given that unweighted graphs are often easier to reason about. A first hurdle to answering this question is that subdividing edges can increase the doubling dimension unboundedly, and it is not difficult to show that the answer to the above question is negative. However, surprisingly, allowing a (1 + Ɛ) distortion between d and d′ enables us bypass this impossibility: we show that for any metric space (V, d), there is an unweighted graph (V′, E′) with shortest-path metric d′ : V′ × V′ → R≥0 such that - for all x, y ∈ V , the distances d(x, y) ≤ d′(x, y) ≤ (1 + Ɛ) ċ d(x, y), and - the doubling dimension for d′ is not much more than that of d, where this change depends only on Ɛ and not on the size of the graph. We show a similar result when both (V, d) and (V′, E′) are restricted to be trees: this gives a simple proof that doubling trees embed into constant dimensional Euclidean space with constant distortion. We also show that our results are tight in terms of the tradeoff between distortion and dimension blowup.
Organizing the tasks in complex design projects

This research is aimed at structuring complex design projects in order to develop better products more quickly. We use a matrix representation to capture both the sequence of and the technical relationships among the many design tasks to be performed. These relationships define the “technical structure” of a design project which is then analyzed in order to find alternative sequences and/or definitions of the design tasks. Such improved design procedures offer opportunities to speed development progress by streamlining the inter-task coordination. After using this technique to model design processes in several organizations, we have developed a design management strategy which focuses attention on the essential information transfer requirements of a technical project. We expect that this research will benefit not only new design tasks that have never been structured before but also long-standing, often repeated design tasks that may have drifted into poor organizational patterns over many years.
Performance Decrement under Psychological Stress

Army trainees unaware that they were serving in an experiment were, under controlled conditions, led to believe that either (1) an aircraft in which they were passengers was about to make an emerge...
Supporting Dynamic Changes in Web Service Environments

The Web has become the universal medium for publishing and using of Web accessible services called Web services. The widespread adoption of XML standards including WSDL, SOAP, and UDDI has spurred an intense research activity to deal with issues related to Web services. One of the most important issues is the management of changes that occur in Web service environments. Web services operate in a highly dynamic environment where changes can be initiated to adapt to evolving business climates. All changes performed to Web services must be efficiently propagated to ensure global consistency. In this paper, we combine Web services, ontologies, and agents to cater for the management of changes in Web services. We address the challenging issues of detection, propagation, and reaction to both internal and external changes to Web services.
Dynamic cache reconfiguration strategies for a cluster-based streaming proxy

The high bandwidth and the relatively long-lived characteristics of digital video are key limiting factors in the wide-spread usage of streaming content over the Internet. The problem is further complicated by the fact that video popularity changes over time. In this paper, we study caching issues for a cluster-based streaming proxy in the face of changing video popularity. We show that the cache placement problem for a given video popularity is NP-complete, and propose the dynamic first fit (DFF) algorithm that give the results close to the optimal cache placement. We then propose minimum weight perfect matching(MWPM) and swapping-based techniques that can dynamically reconfigure the cache placement to adapt to changing video popularity with minimum copying overhead. Our simulation results show that MWPM reconfiguration can reduce the copying overhead by a factor of more than two, and that swapping-based reconfiguration can further reduce the copying overhead compared to MWPM, and allow for the tradeoffs between the reconfiguration copying overhead and the proxy bandwidth utilization.
The social value of Science Shops: a Cost-Benefit Analysis

We describe and apply a method to determine the net social benefits of science shops. University departments operating as science shops coordinate research projects for individuals or civil society organizations (CSO) lacking the financial means to turn to professional consultancy bureaus. Three cases are analyzed; the science shops atWageningen, Brussels and Eindhoven. After investigation, it appears that under the normal assumptions for the application of CBA, the science shops concerned show positive net social benefits.
Hydrologic processes in global climate change

Popular concerns over global resource issues have focused attention on the description of the dynamics of hydrologic processes at scales much larger than the traditional river basin. Improved, remotely sensed land surface data on a global scale and improved large-scale global circulation models (GCMs) have fueled the need to better integrate hydrologic processes with land surface features and atmospheric dynamics. Until recently, however, the interaction between climate modelers and hydrologists has been weak. Given a prescribed geographic distribution of sea surface temperature, GCM models can approximately simulate long-term, large area mean precipitation, runoff, and other hydrologic variables. Runoff is the amount of precipitation leaving an area in surface drainage in contrast to that which infiltrates into the subsurface. Some hydrologists have been involved in so-called “effects” modeling, in which they attempt to use GCM output to assess the sensitivity of hydrologic systems to global warming. These efforts have made hydrologists painfully aware of the incompatibility of temporal and spatial scales between the GCMs and basin-scale hydrologic models in common use. GCM model simulations with and without mountains have been used to demonstrate the role of the mountains in controlling soil wetness in the North American mid-continent “Manabe, 1990”. Improvements in spatial resolution of the land surface does affect model performance, particularly in the influence of orographic processes and the scale-dependence of the representation of mountain-induced gravity wave drag. Simulation of runoff at the river basin scale using a GCM “pot model” (a lumped representation of hydrologic processes) has been compared with simple nonlinear soil moisture models. The results suggest that runoff predicted by the GCM has statistical characteristics much more similar to the rainfall input of the model itself than it does to actual observed runoff. Incorporation of a relatively simple representation of the soil moisture dependence of infiltration, along with a simple representation of base flow, leads to much better agreement with the statistical character of simulated runoff. Hydrologic characterization of large areas will improve as spatially distributed soil moisture modeling continues to evolve and remotely sensed data becomes available from the Earth Observing System [Wood, 1990].
Decentralized optimal dispatch of photovoltaic inverters in residential distribution systems

Decentralized methods for computing optimal real and reactive power setpoints for residential photovoltaic (PV) inverters are developed in this paper. It is known that conventional PV inverter controllers, which are designed to extract maximum power at unity power factor, cannot address secondary performance objectives such as voltage regulation and network loss minimization. Optimal power flow techniques can be utilized to select which inverters will provide ancillary services, and to compute their optimal real and reactive power setpoints according to well-defined performance criteria and economic objectives. Leveraging advances in sparsity-promoting regularization techniques and semidefinite relaxation, this paper shows how such problems can be solved with reduced computational burden and optimality guarantees. To enable large-scale implementation, a novel algorithmic framework is introduced - based on the so-called alternating direction method of multipliers - by which optimal power flow-type problems in this setting can be systematically decomposed into sub-problems that can be solved in a decentralized fashion by the utility and customer-owned PV systems with limited exchanges of information. Since the computational burden is shared among multiple devices and the requirement of all-to-all communication can be circumvented, the proposed optimization approach scales favorably to large distribution networks.
Every sequence is decompressible from a random one

Kucera and Gacs independently showed that every infinite sequence is Turing reducible to a Martin-Lof random sequence. We extend this result to show that every infinite sequence S is Turing reducible to a Martin-Lof random sequence R such that the asymptotic number of bits of R needed to compute n bits of S, divided by n, is precisely the constructive dimension of S. We show that this is the optimal ratio of query bits to computed bits achievable with Turing reductions. As an application of this result, we give a new characterization of constructive dimension in terms of Turing reduction compression ratios.
Digital I/Q demodulator

I/Q demodulation is a common and useful RF signal processing technique used in charged-particle accelerators. When implemented with conventional analog RF components, a number of inherent errors can degrade the I/Q Demodulator performance, including gain balance, quadrature-phase balance, DC offsets, impedance match, and carrier leakage. Recent advances in high-speed analog-to-digital converters allow the I/Q demodulator to be implemented digitally, greatly reducing these systematic errors. This paper describes the design of a digital I/Q demodulator that will be applied to the PEP-II B factory.
Software development with two port calibration techniques for RHIC impedance measurements

The coupling impedance of accelerator devices is measured by simulating the beam with a central wire and measuring the scattering parameters of the system. The wire pipe system forms a mismatch with the 50 ohm transmission line. An integrated software environment has been developed in LabVIEW, for the Macintosh. The program measures the scattering parameters of some known standards, determines the correct scattering parameters of a device using TRL calibration technique and gives the impedance of the device. Its performance has been tested for some known microwave devices. >
On the global regularity of wave maps in the critical Sobolev norm

We extend the recent result of T.Tao (5) to wave maps defined from the Minkowski space R n+1 , n � 5, to a target manifold N which pos- sesses a "bounded parallelizable" structure. This is the case of Lie groups, homogeneous spaces as well as the hyperbolic spaces H N. General compact Riemannian manifolds can be imbedded as totally geodesic submanifolds in bounded parallelizable manifolds, see (1), and therefore are also covered, in principle, by our result. Compactness of the target manifold, which seemed to play an important role in (5), turns out however to play no role in our discus- sion. Our proof follows closely that of (5) and is based, in particular, on its remarkable microlocal gauge renormalization idea.
Rational Parking Functions and Catalan Numbers

The “classical” parking functions, counted by the Cayley number (n+1) n−1, carry a natural permutation representation of the symmetric group S n in which the number of orbits is the Catalan number $${\frac{1}{n+1} \left( \begin{array}{ll} 2n \\ n \end{array} \right)}$$ . In this paper, we will generalize this setup to “rational” parking functions indexed by a pair (a, b) of coprime positive integers. These parking functions, which are counted by b a−1, carry a permutation representation of S a in which the number of orbits is the “rational” Catalan number $${\frac{1}{a+b} \left( \begin{array}{ll} a+b \\ a \end{array} \right)}$$ . First, we compute the Frobenius characteristic of the S a -module of (a, b)-parking functions, giving explicit expansions of this symmetric function in the complete homogeneous basis, the power-sum basis, and the Schur basis. Second, we study q-analogues of the rational Catalan numbers, conjecturing new combinatorial formulas for the rational q-Catalan numbers $${\frac{1}{[a+b]_{q}} {{\left[ \begin{array}{ll} a+b \\ a \end{array} \right]}_{q}}}$$ and for the q-binomial coefficients $${{{\left[ \begin{array}{ll} n \\ k \end{array} \right]}_{q}}}$$ . We give a bijective explanation of the division by [a+b] q that proves the equivalence of these two conjectures. Third, we present combinatorial definitions for q, t-analogues of rational Catalan numbers and parking functions, generalizing the Shuffle Conjecture for the classical case. We present several conjectures regarding the joint symmetry and t = 1/q specializations of these polynomials. An appendix computes these polynomials explicitly for small values of a and b.
Toroidal magnetic fields in type II superconducting neutron stars

We determine constraints on the form of axisymmetric toroidal magnetic fields dictated by hydrostatic balance in a type II superconducting neutron star with a barotropic equation of state. Using Lagrangian perturbation theory, we find the quadrupolar distortions due to such fields for various models of neutron stars with type II superconducting and normal regions. We find that the star becomes prolate and can be sufficiently distorted to display precession with a period of the order of years. We also study the stability of such fields using an energy principle, which allows us to extend the stability criteria established by R. J. Tayler for normal conductors to more general media with magnetic free energy that depends on density and magnetic induction, such as type II superconductors. We also derive the growth rate and instability conditions for a specific instability of type II superconductors, first discussed by P. Muzikar, C. J. Pethick and P. H. Roberts, using a local analysis based on perturbations around a uniform background.