cssi/SciSciGPT-SciSciNet huggingface dataset:
Mining numerical data – a rough set approach

We present an approach to mining numerical data based on rough set theory using calculus of attribute-value blocks. An algorithm implementing these ideas, called MLEM2, induces high quality rules in terms of both simplicity (number of rules and total number of conditions) and accuracy. MLEM2 induces rules not only from complete data sets but also from data with missing attribute values, with or without numerical attributes. Additionally, we present experimental results on a comparison of three commonly used discretization techniques: equal interval width, equal interval frequency and minimal class entropy (all three methods were combined with the LEM2 rule induction algorithm) with MLEM2. Our conclusion is that even though MLEM2 was most frequently a winner, the differences between all four data mining methods are statistically insignificant.
An Analysis of Federal LandBank Borrowers

This paper uses Federal LandBank Data to examine loan characteristics and farm financial characteristics. Given that farm financial characteristics and loan interest rates can change, this paper examines if current farm financial characteristics can predict the current loan interest rate. In addition, this paper tests to see if farm profitability can be predicted using two debt financial characteristics. Results indicate that interest rates and profitability are not very predicatable based on current farm financials information once the loan progresses.
Logistical Packaging for Food Marketing Systems

This chapter discusses logistical packaging and its role in food marketing systems. Logistical packaging is called by a number of different names, such as distribution packaging, transit packaging, industrial packaging, intermediate packaging and shipping containers. The term logistical packaging is used throughout this chapter as it stresses the importance of integrating packaging with all of the activities in a supply chain. Supply chains range from hand delivery of a neighbour’s garden vegetables to the importation of exotic and rare processed foods, using specialised trans-global distribution systems. Farm markets, conventional grocery stores, restaurants, fast food take-outs, food service institutions and direct marketing systems are supplied by a myriad of operational variations. They are also supplied by a wide range of package types, sizes and formats. Logistical activities in a typical processed food supply chain begin at the farm. Commodities are transported to factories in bulk, or semi-bulk, packages, where the food is processed and packaged to add value. Unit loads are transported to wholesalers or retail distribution centres (RDC) where orders are picked into mixed loads, delivered to retail stores and broken down for retail display. There, consumers buy an assortment of packages and transport them home, where all of the packages are emptied, discarded and either shipped to a recycling facility or collected and transported to a landfill. This process is shown in Fig. 4.1. Packaging affects the cost of every logistical activity in a supply chain, and has a significant impact on productivity. Transport and storage costs are directly related to the size and density of packages. Handling cost depends on unit loads. Inventory control depends on the accuracy of identification systems. Customer service depends on how well the packages protect products and how easy the package is to open, display and sell. The environmental impact depends on the materials, method of manufacture, reuse and disposal of the packaging. The first section of this chapter discusses the functional requirements for logistical packaging to protect, add value and communicate. The second section discusses how packaging is related to the physical activities in factory operations, in transit, in warehouses and in retail stores. The third section discusses testing and evaluating packages for shock, vibration and compression performance. The final section describes the most common logistical packaging forms: corrugated fibreboard boxes, shrink-film bundles, plastic totes, stretch wrapping and pallets.
Competing Auctions with Discrete Valuations

This paper considers a situation of two sellers of perfectly substitutable items competing in publicly announced reserve prices to induce potential bidders participation at their auction. After learning their own valuations and upon observing the reserve prices, potential bidders make a participation decision consisting of a unique auction to visit. The participation decision is modelled as a standard Bayesian- Nash game. Once participation decisions are realized, each bidder observes the aggregate number of bidders at the auction, and bidding games unfold. For extreme parameter values of the distribution of potential-bidders' valuation, it is shown that a unique, symmetric, pure-strategy equilibrium in reserve prices exists. For other values however, no equilibrium in pure strategy exists. The results share the non-existence feature of Hotelling location type models. The model also contributes to the recent literature on directed search.
New tantalum polychalcogenides with infinite anionic chains: K12Ta6Se35 and KTaTe3

Abstract The new compounds K12Ta6Se35 and KTaTe3 have been synthesized through the reaction of Ta metal with a K2Qn(Q = Se, Te) flux. K12Ta6Se35, crystallizes with 4 formula units in space group Pbcn of the orthorhombic system in a cell of dimensions a = 8.3390(17) A, b = 13.259(3) A, c = 56.023(11) A (t = −120 °C). KTaTe3 crystallizes with 20 formula units (or 4 formula units of K5Ta5Te15) in the monoclinic space group P21/c in a cell of dimension a = 7.7177(15) A, b= 13.826(3) A, c = 30.981(6) A, and β = 90.11(3)° (t = −120 °C). Each structure consists of infinite anionic chains of Ta-containing polyhedra well separated by K+ cations. In K12Ta6Se35 there are Ta2Se11 units formed by the face sharing of two TaSe7 elongated bipyramids. These Ta2Se11 units are in turn interconnected by Se2 and Se3 units to form α1[Ta6Se3Se3512−]infinite chains. In KTaTe3, the α1[TaTe3−] infinite chains arise from the face sharing of distorted TaTe6 octahedra.
Distances from the Correlation Between Galaxy Luminosities and Rotation Rates

A large luminosity-linewidth template sample is now available, improved absorption corrections have been derived, and there are a statistically significant number of galaxies with well determined distances to supply the zero point. A revised estimate of the Hubble Constant is H0 = 77±4 km s−1 Mpc−1 where the error is the 95% probable statistical error. Systematic uncertainties are potentially twice as large.
Mixtures of deterministic-probabilistic networks and their AND/OR search space

The paper introduces mixed networks, a new framework for expressing and reasoning with probabilistic and deterministic information. The framework combines belief networks with constraint networks, defining the semantics and graphical representation. We also introduce the AND/OR search space for graphical models, and develop a new linear space search algorithm. This provides the basis for understanding the benefits of processing the constraint information separately, resulting in the pruning of the search space. When the constraint part is tractable or has a small number of solutions, using the mixed representation can be exponentially more effective than using pure belief networks which model constraints as conditional probability tables.
Combined radiologic/operative therapy in the treatment of cervical malignancy

Abstract In an attempt to increase survival in cervical malignancies, a study was started in 1950 with preoperative internal and external irradiation followed by radical operation. The study was made at Confederate Memorial Medical Center in Shreveport, Louisiana. Three previous reports seemed to indicate an advantage to this combined approach. This report deals with the current findings since the preliminary results were reported.
Institution-Induced Productivity Differences and Patterns of International Capital Flows

Abstract: This paper studies theoretically how the cross-country differences in the institutional quality (IQ) of the domestic credit markets shape the patterns of international capital flows when such IQ differences cause productivity differences across countries. IQ affects productivity by changing productivity-agency cost trade-offs across heterogeneous investment projects, which have opposite effects on the investment and capital flows from exogenous productivity differences. The overall effect of IQ could generate U-shaped responses of the investment and capital flows. This means that capital could flow from middle-income to low-income and high-income countries; and starting from a low IQ, a country could experience both growth and a current account surplus after an institutional reform. More generally, the results here offer some cautions when interpreting the evidence on the role of productivity and institutional differences on capital flows and question the validity of using financial frictions as a proxy for the quality of financial institutions.;
Asymmetrical Bending of Conical Shells

Equations are derived based on A.L.GOLDENVEIZER’s theory; solution is developed applicable to truncated cones of finite length simply supported along two generators and having any type of support at ends; numerical results are obtained by using electronic computer.
Fast Greedy Weighted Fusion

Loop fusion is an important compiler strategy for managing memory hierarchy. By fusing loops that use the same data elements, a compiler can reduce the distance between accesses to the same datum and avoid costly cache misses. Unfortunately the problem of optimal loop fusion for reuse has been shown to be NP-hard, so compilers must resort to heuristics to avoid unreasonably long compile times. Greedy strategies are often excellent heuristics that produce high-quality solutions quickly. We present an algorithm for greedy weighted fusion, in which the heaviest edge (the one with the most reuse) is selected for possible fusion on each step. The algorithm is shown to be fast in the sense that it takes O(V(E+V)) time, which is arguably optimal for producing the greedy solution. In addition, this algorithm has the advantage that it requires only O(E) edge reweighting operations after fusions. This means that it is suitable for use on the problem of enhancing cache reuse, for which the ideal reweighting operation is much more complex than addition. If each reweighting operation requires no more than O(V) time, the time bound of the overall fusion process remains at O(V(E+V)).
Joint Tests for Long Memory and Non-linearity: The Case of Purchasing Power Parity

A pervasive finding of unit roots in macroeconomic data often runs counter to intuition regarding the stochastic nature of the process under consideration. Two econometric techniques have been utilized in an attempt to resolve the finding of unit roots, namely long memory and models that depart from linearity. While the use of long memory and stochastic regime switching models have developed almost independently of each other, it is now clear that the two modeling techniques can be intimately linked. In particular, both modeling techniques have been used in isolation to study the dynamics of the real exchange rate. To determine the importance of each technique in this context, I employ a testing and estimation procedure that allows one to jointly test for long memory and non-linearity (regime switching behavior) of the STAR variety. I find that there is substantial evidence of non-linear behavior for the real exchange rate for many developing and European countries, with little evidence for ESTAR non-linearity for countries outside the European continent including Japan and Canada. In cases where non-linearity is found, I also find significant evidence of long memory for the majority of the countries in my sample. Thus, long memory and non-linearity can also be viewed as compliments rather than substitutes. On the other hand, a combination of long memory and non-linearity may be a promising research avenue for pursuing an answer to the paradox
High Critical Current Densities in Nb3Sn Films with Engineered Microstructures — Artificial Pinning Microstructures

Films with layers of Nb, Cu, and Sn have been fabricated to simulate a Nb3Sn bronze-type process. These Nb3Sn films have produced critical current densities greater than 1 × 106 A/cm2 at 4.2 K and 7.5 T. Niobium films doped with Y, Sc, Dy, Al2O3, and Ti have been deposited with e-beam co-evaporation onto 75 mm diameter Si wafers with a 100 nm SiO2 buffer layer. The Nb layer was followed by a layer of Cu and a layer of Sn to complete the bronze-type process. The films with the highest Jc had about 8 vol. % Sc and about 18 vol. % Al2O3. Characterization of the microstructure by TEM shows that these high Jc films contained high density of inclusions about 5 nm in size and that the grain size of the Nb3Sn is about 20–25 nm for samples heat treated at 700°C for up to eight hours.
The Billable Hours Derby: Empirical Data on the Problems and Pressure Points

If you ask law firm attorneys to identify their biggest complaint related to private law practice, most will probably respond with one word: billing. At the same time, clients are likely to identify billing as their most serious concern associated with obtaining legal services. The irony in clients and attorneys sharing frustration over hourly billing relates to the fact that the initial interest in hourly billing stemmed from attorneys' desire to be efficient and to maximize their earnings and clients' preference for only paying for the actual time expended on their behalP Since the 1960s, hourly
Social Status and Badge Design

Many websites encourage user participation via the use of virtual rewards like badges. While badges typically have no explicit value, they act as symbols of social status within a community. In this paper, we study how to design virtual incentive mechanisms that maximize total contributions to a website when users are motivated by social status. We consider a game-theoretic model where users exert costly effort to make contributions and, in return, are awarded with badges. The value of a badge is determined endogenously by the number of users who earn an equal or higher badge; as more users earn a particular badge, the value of that badge diminishes for all users. We show that among all possible mechanisms for assigning status-driven rewards, the optimal mechanism is a leaderboard with a cutoff: users that contribute less than a certain threshold receive nothing while the remaining are ranked by contribution. We next study the necessary features of approximately optimal mechanisms and find that approximate optimality is influenced by the the convexity of status valuations. When status valuations are concave, any approximately optimal mechanism must contain a coarse status partition, i.e. a partition of users into status classes whose size will grow as the population grows. Conversely when status valuations are convex, we prove that fine partitioning, that is a partition of users into status classes whose size stays constant as the population grows, is necessary for approximate optimality.
Deterministic Time-Varying Packet Fair Queueing for Integrated Services Networks

In integrated services networks, the provision of Quality of Service (QoS) guarantees depends critically upon the scheduling algorithm employed at the network layer. In this work we review fundamental results on scheduling, and we focus on Packet Fair Queueing (PFQ) algorithms, which have been proposed for QoS wireline-wireless networking. The basic notion in PFQ is that the bandwidth allocated to a session is proportional to a positive weight ?i. Because of the fixed weight assignment, the inherent in PFQ delay-bandwidth coupling imposes limitations on the range of QoS that can be supported. We develop PFQ with deterministic time-varying weight assignments, and we propose a low-overhead algorithm capable of supporting arbitrary piecewise linear service curves which achieve delay-bandwidth decoupling. Unlike existing service-curve based algorithms, our time-varying PFQ scheme does not exhibit the punishment phenomenon, and allows sessions to exploit the extra bandwidth in under-loaded networks.
A hybrid systems model for simple manipulation and self-manipulation systems

Rigid bodies, plastic impact, persistent contact, Coulomb friction, and massless limbs are ubiquitous simplifications introduced to reduce the complexity of mechanics models despite the obvious physical inaccuracies that each incurs individually. In concert, it is well known that the interaction of such idealized approximations can lead to conflicting and even paradoxical results. As robotics modeling moves from the consideration of isolated behaviors to the analysis of tasks requiring their composition, a mathematically tractable framework for building models that combine these simple approximations yet achieve reliable results is overdue. In this paper we present a formal hybrid dynamical system model that introduces suitably restricted compositions of these familiar abstractions with the guarantee of consistency analogous to global existence and uniqueness in classical dynamical systems. The hybrid system developed here provides a discontinuous but self-consistent approximation to the continuous though possibly very stiff and fast dynamics of a physical robot undergoing intermittent impacts. The modeling choices sacrifice some quantitative numerical efficiencies while maintaining qualitatively correct and analytically tractable results with consistency guarantees promoting their use in formal reasoning about mechanism, feedback control, and behavior design in robots that make and break contact with their environment.
Organizational Design, Information Transfer, and the Acquisition of Rent-Producing Resources

Within the resource-based view of the firm, a dynamic story has emerged in which the knowledge accumulated over the history of a firm and embedded in organizational routines and structures influences the firm's ability to recognize the value of new resources and capabilities. This paper explores the possibility of firms to select organizational designs that increase the likelihood that they will recognize and value rent-producing resources and capabilities. A computational model is developed to study the tension between an organization's desire to explore its environment for new capabilities and the organization's need to exploit existing capabilities. Support is provided for the proposition that integration, both externally and internally, is an important source of dynamic capability. The model provides greater insight into the tradeoffs between these two forms of integration and suggests when one form may be preferred over another. In particular, evidence is provided that in uncertain environments, the ability to explore possible alternatives is critical while in more certain environments, the ability to transfer information internally is paramount.
Exact-slow fast decomposition of the H/sub /spl infin// filtering Riccati equation of singularly perturbed systems

The H/sub /spl infin// filtering Riccati equation, associated with filtering problem, of standard singularly perturbed systems is completely and exactly decomposed into two reduced-order H/sub /spl infin// filtering Riccati equations corresponding to the slow and fast time scales. The pure-slow and pure-fast H/sub /spl infin// filtering Riccati equations are nonsymmetric ones; however, their O(/spl epsiv/) perturbations are symmetric. It will be shown that the Newton method is very efficient for solving the obtained nonsymmetric H/sub /spl infin// filtering Riccati equations. This method is suitable for parallel computations. Due to complete and exact decomposition of the Riccati equation, this procedure might produce new insight into the two-time scale H/sub /spl infin// output feedback problem.
Counternull Value of an Effect Size

The counternull value of an effect size is the nonnull magnitude of effect size that is supported by exactly the same amount of evidence as supports the null value of the effect size. That is, if the counternull value were taken as the null hypothesis, the resulting P value would be the same as the obtained P value for the actual null hypothesis. Reporting the counternull, in addition to the P value, virtually eliminates the common error of equating failure to reject the null with the estimation of the effect size as equal to zero. Keywords: effect size; null hypothesis; P value; statistical significance
Text based dialog act classification for multiparty meetings

This paper evaluates the performance of various machine learning approaches and their combination for text based dialog act (DA) classification of meetings data. For this task, boosting and three other text based approaches previously described in the literature are used. To further improve the classification performance, three different combination schemes take into account the results of the individual classifiers. All classification methods are evaluated on the ICSI Meeting Corpus based on both reference transcripts and the output of a speech-to-text (STT) system. The results indicate that both the proposed boosting based approach and a method relying on maximum entropy substantially outperform the use of mini language models and a simple scheme relying on cue phrases. The best performance was achieved by combining individual methods with a multilayer perceptron.
Developing an action plan for patient radiation safety in adult cardiovascular medicine. Proceedings from the Duke University Clinical Research Institute/American College of Cardiology Foundation/American Heart Association Think Tank Held on February 28, 2011.

Technological advances and increased utilization of medical testing and procedures have prompted greater attention to ensuring the patient safety of radiation use in the practice of adult cardiovascular medicine. In response, representatives from cardiovascular imaging societies, private payers, government and nongovernmental agencies, industry, medical physicists, and patient representatives met to develop goals and strategies toward this end; this report provides an overview of the discussions. This expert “think tank” reached consensus on several broad directions including: the need for broad collaboration across a large number of diverse stakeholders; clarification of the relationship between medical radiation and stochastic events; required education of ordering and providing physicians, and creation of a culture of safety; development of infrastructure to support robust dose assessment and longitudinal tracking; continued close attention to patient selection by balancing the benefit of cardiovascular testing and procedures against carefully minimized radiation exposures; collation, dissemination, and implementation of best practices; and robust education, not only across the healthcare community but also to patients, the public, and media. Finally, because patient radiation safety in cardiovascular imaging is complex, any proposed actions need to be carefully vetted (and monitored) for possible unintended consequences.
The fibrous nature of the human cervix, and its relation to the isthmic segment in gravid and nongravid uteri.

The fibrous nature of the human cervix and its relation to the isthmic segment in 12 gravid and 46 nongravid uteri was investigated. In the nonpregnant human uterus the cervix was found to be composed predominately of fibrous connective tissue with an average of only about 15% smooth muscle. The tissue superior to the cervix is composed mostly of smooth muscle. The histologic internal os was found to be variable with respect to the constricted area known as the isthmic canal. Thus the nonpregnant isthmus is an indefinite variable segment which is composed principally of smooth muscle which is lined by a transitional epithelium which is bounded below by the fibrous cervix and which above blends imperceptibly with the remainder of the uterine musculature. In the 3rd month of pregnancy the isthmus elongates which is considered a hypertrophic response to pregnancy. When elongation occurs the products of conception are confined to the portion of the uterus which is superior to the isthmic canal. When the products of conception require more space the isthmic musculature unfolds to accommodate them and thus comes to make up a part of the wall of the ovum chamber. It is concluded that from both anatomic and functional standpoints the isthmus forms a unit with the remainder of the uterine musculature. It is believed that the concept of the isthmus uteri as separate distinct entity should be eliminated and that rather the uterus should be considered as being composed of 2 major parts corpus and cervix according to whether the fundamental structure is chiefly muscular of chiefly fibrous.
Proof Nets and the Complexity of Processing Center Embedded Constructions

This paper shows how proof nets can be used to formalize the notion of ’’incomplete dependency‘‘ used in psycholinguistic theories of the unacceptability of center embedded constructions. Such theories of human language processing can usually be restated in terms of geometrical constraints on proof nets. The paper ends with a discussion of the relationship between these constraints and incremental semantic interpretation.
THE GALILEO ATTITUDE AND ARTICULATION CONTROL SYSTEM: A RADIATION-HARD, HIGH PRECISION, STATE-OF-THE-ART CONTROL SYSTEM

The Galileo Mission and Spacecraft design impose tight requirements on the Attitude and Articulation Control System (AACS). These requirements, coupled with the flexible spacecraft, the need for autonomy, and a severe radiation environment, pose a great challenge for the AACS designer. The resulting design and implementation are described, along with the discovery and solution of the Single-Event Upset problem. The status of the testing of the AACS in the Integration and Test Laboratory as well as at the spacecraft level is summarized.
The RPC-based proposal for the ATLAS forward muon trigger upgrade in view of super-LHC

The innermost station of the present ATLAS forward muon detector needs to be upgraded for the super-LHC. We present a proposal to replace it with a sandwiched detector composed of several layers of small-radius Monitored Drift Tube chambers (sMDT) for precision tracking measurement and two stations of multi-gap Resistive Plate Chambers (mRPC) for triggering purpose. We describe the layout of the upgraded detector and the trigger strategy. Several modifications to the RPCs used in the ATLAS barrel region are needed to satisfy the super-LHC requirements. Various studies with the proposed mRPC timing resolution, spatial resolution and rate capability have been performed.
On the Witten-Reshetikhin-Turaev representations of mapping class groups

Abstract.We consider a central extension of the mapping class group of a surface with acollection of framed colored points. The Witten-Reshetikhin-Turaev TQFTs associ-ated to SU(2) and SO(3) induce linear representations of this group. We show thatthe denominators of matrices which describe these representations over a cyclotomicﬁeld can be restricted in many cases. In this way, we give a proof of the known resultthat if the surface is a torus with no colored points, the representations have ﬁniteimage. Recall that an object in a cobordism category of dimension 2+1 is a closedoriented surfaces Σ perhaps with some speciﬁed further structure. A morphismMfrom Σ to Σ ′ is (loosely speaking) a compact oriented 3-manifold perhaps withsome speciﬁed further structure, called a cobordism, whose boundary is the disjointunion of −Σ and Σ ′ .A morphism M ′ from Σ to Σ ′′ is composed with a morphismfrom Σ to Σ ′ by gluing along Σ ,inducing any required extra structure from thestructures on Mand M ′
International Financial Integration and Crisis Intensity

i»?This paper analyzes the causes of the 2008â€“2009 financial crisis together with its manifestations, using a Multiple Indicator Multiple Cause (MIMIC) model. The analysis is conducted on a cross-section of 85 economies; I focus on international financial linkages that may have both allowed the crisis to spread across economies, and/or provided insurance. The model of the cross-economy incidence of the crisis combines 2008â€“2009 changes in real gross domestic product (GDP), the stock market, economy credit ratings, and the exchange rate. The key domestic determinants of crisis incidence that I consider are taken from the literature, and are measured in 2006 : real GDP per capita; the degree of credit market regulation; and the current account, measured as a fraction of GDP. Above and beyond these three national sources of crisis vulnerability, I add a number of measures of both multilateral and bilateral financial linkages to investigate the effects of international financial integration on crisis incidence. I ask three questions, with a special focus on Asian economies. First, did the degree of an economyâ€™s multilateral financial integration help explain its crisis? Second, what about the strength of its bilateral financial ties with the United States and the key Asian economics of the Peopleâ€™s Republic of China, Japan, and the Republic of Korea? Third, did the presence of a bilateral swap line with the Federal Reserve affect the intensity of an economyâ€™s crisis? I find that neither multilateral financial integration nor the existence of a Fed swap line is correlated with the cross-economy incidence of the crisis. There is mild evidence that economies with stronger bilateral financial ties to the United States (but not the large Asian economies) experienced milder crises. That is, more financially integrated economies do not seem to have suffered more during the most serious macroeconomic crisis in decades. This strengthens the case for international financial integration; if the costs of international financial integration were not great during the Great Recession, when could we ever expect them to be larger?
Looking beyond Enrollment: The Causal Effect of Need-Based Grants on College Access, Persistence, and Graduation

The government has attempted to ameliorate gaps in college access and success by providing need-based grants, but little evidence exists on the long-term impacts of such aid. We examine the effects of the Florida Student Access Grant (FSAG) using a regression-discontinuity strategy and exploiting the cut-off used to determine eligibility. We find that grant eligibility had a positive effect on attendance, particularly at public 4-year institutions. Moreover, FSAG increased the rate of credit accumulation and bachelor’s degree completion within 6 years, with a 22% increase for students near the eligibility cut-off. The effects are robust to sensitivity analysis.
Continuous Time Dynamic PET Imaging Using List Mode Data

We describe a method for computing a continuous time estimate of dynamic changes in tracer density using list mode PET data. The tracer density in each voxel is modeled as an inhomogeneous Poisson process whose rate function can be represented using a cubic B-spline basis. An estimate of these rate functions is obtained by maximizing the likelihood of the arrival times of each detected photon pair over the control vertices of the spline. By resorting the list mode data into a standard sinogram plus a "timogram" that retains the arrival times of each of the events, we are able to perform efficient computation that exploits the symmetry inherent in the ordered sinogram. The maximum likelihood estimator uses quadratic temporal and spatial smoothness penalties and an additional penalty term to enforce non-negativity. Corrections for scatter and randoms are described and the results of studies using simulated and human data are included.
Systems Thinking: Common Ground or Untapped Territory?

At international gatherings of systems scholars, the term ‘systems thinking’ elicits understanding nods and smiles. Such thinking, it would appear, is a way this largely academic community works ‘all together now’, thinking in a systemic way about our varied areas of inquiry. But how common is this understanding among us? Assessing the degree to which we work ‘all together now’ requires recognizing the different assumptions we make about what systems thinking means. So powerful is systems thinking's capacity to holistically address twenty-first-century problems that much has been written about it for laypeople. This article presents a content analysis of 14 popular books on systems thinking, revealing that ISSS members’ understanding nods and smiles belie a plurality of meanings assigned to systems thinking and claims about what it means to be a systems thinker. Copyright © 2012 John Wiley & Sons, Ltd.
On Vassiliev knot invariants induced from finite type 3-manifold invariants

We prove that the knot invariant induced by a Z-homology 3sphere invariant of order ≤ k in Ohtsuki’s sense, where k ≥ 4, is of order ≤ k − 2. The method developed in our computation shows that there is no Z-homology 3-sphere invariant of order 5.
Bayesian Inference of Arrival Rate and Substitution Behavior from Sales Transaction Data with Stockouts

When an item goes out of stock, sales transaction data no longer reflect the original customer demand, since some customers leave with no purchase while others substitute alternative products for the one that was out of stock. Here we develop a Bayesian hierarchical model for inferring the underlying customer arrival rate and choice model from sales transaction data and the corresponding stock levels. The model uses a nonhomogeneous Poisson process to allow the arrival rate to vary throughout the day, and allows for a variety of choice models. Model parameters are inferred using a stochastic gradient MCMC algorithm that can scale to large transaction databases. We fit the model to data from a local bakery and show that it is able to make accurate out-of-sample predictions, and to provide actionable insight into lost cookie sales.
Low-Cycle Thermal Mechanical Fatigue Testing

A test method is described for performing uniaxial low-cycle thermal mechanical fatigue tests at elevated temperatures on nickel-base superalloys. Both smooth specimen crack initiation and notched specimen crack propagation testing is discussed. Standard closed loop servohydraulic testing machines with closed loop electric induction heaters are utilized. The temperature and mechanical strain are independently controlled, allowing for a wide range of relationships between temperature and mechanical strain. Tubular specimens are directly inductively heated in air and cooled with compressed air. The temperature is measured with a radiation pyrometer which eliminates thermocouples and premature failures caused by welded thermocouples. Axial strain in the specimen is measured from machined internal ridges on the specimen utilizing a linear variable differential transformer and a quartz internal extensometer. An electronic system compensates for the thermal expansion component of strain for both the control loop and the recorders. This system permits direct recording of the load-induced mechanical strain. Load-strain hysteresis loops and strain-temperature plots can simply be recorded during the test.
Dark current in GaAs/Al x Ga 1-x As quantum well infrared detectors

It is not clear whether the tunneling current in QWIPs depends just on the energy corresponding to motion perpendicular to the plane of the quantum well or on the total energy. In order to get a quantitative assessment of the contribution of energy corresponding to motion in the plane of the quantum well to the dark current we use the following approach. We calculate the dark current in GaAs/Al x Ga 1-x s quantum well infrared detectors for both tunneling dependent only on Ez, and tunneling dependent on the total energy, and compare the results to experimental data. Comparison of theoretical results with experimental data at 40K shows that motion in the plane of the quantum well plays a significant role in determining the tunneling dark current. Corrections are made to Levine's original formula. Variation of the dark current with barrier width and doping density is systematically studied. It is shown that increasing the barrier width and/or decreasing the doping density in the well do not always reduce the dark current.
The Meta Distribution of the SIR in Poisson Bipolar and! Cellular Networks

The calculation of the SIR distribution at the typical receiver (or, equivalently, the success probability of transmissions over the typical link) in Poisson bipolar and cellular networks with Rayleigh fading is relatively straightforward, but it only provides limited information on the success probabilities of the individual links. This paper focuses on the meta distribution of the SIR, which is the distribution of the conditional success probability $P_{\rm{ s}}$ given the point process, and provides bounds, an exact analytical expression, and a simple approximation for it. The meta distribution provides fine-grained information on the SIR and answers questions such as “What fraction of users in a Poisson cellular network achieve 90% link reliability if the required SIR is 5 dB?” Interestingly, in the bipolar model, if the transmit probability $p$ is reduced while increasing the network density $\lambda$ such that the density of concurrent transmitters $\lambda p$ stays constant as $p\rightarrow 0$ , $P_{\rm{ s}}$ degenerates to a constant, i.e., all links have exactly the same success probability in the limit, which is the one of the typical link. In contrast, in the cellular case, if the interfering base stations are active independently with probability $p$ , the variance of $P_{\rm{ s}}$ approaches a non-zero constant when $p$ is reduced to 0 while keeping the mean success probability constant.
Electron Impact Excitation of Ions

The ancient curiosity of “what produces the light” still motivates research on electron impact excitation of ions. We have developed extensive knowledge of the subject which relies on detailed information about atomic structure and a conviction that quantum theory, in principle, correctly describes the atomic structure and the collision dynamics. Still, we are unable to predict cross sections or rates for this process with sufficient reliability to satisfy our needs.
P3: toward privacy-preserving photo sharing

With increasing use of mobile devices, photo sharing services are experiencing greater popularity. Aside from providing storage, photo sharing services enable bandwidth-efficient downloads to mobile devices by performing server-side image transformations (resizing, cropping). On the flip side, photo sharing services have raised privacy concerns such as leakage of photos to unauthorized viewers and the use of algorithmic recognition technologies by providers. To address these concerns, we propose a privacy-preserving photo encoding algorithm that extracts and encrypts a small, but significant, component of the photo, while preserving the remainder in a public, standards-compatible, part. These two components can be separately stored. This technique significantly reduces the accuracy of automated detection and recognition on the public part, while preserving the ability of the provider to perform server-side transformations to conserve download bandwidth usage. Our prototype privacy-preserving photo sharing system, P3, works with Facebook, and can be extended to other services as well. P3 requires no changes to existing services or mobile application software, and adds minimal photo storage overhead.
FRÉCHET DISTANCE PROBLEMS IN WEIGHTED REGIONS

We discuss two versions of the Frechet distance problem in weighted planar subdivisions. In the first one, the distance between two points is the weighted length of the line segment joining the points. In the second one, the distance between two points is the length of the shortest path between the points. In both cases, we give algorithms for finding a (1 + ∊)-factor approximation of the Frechet distance between two polygonal curves. We also consider the Frechet distance between two polygonal curves among polyhedral obstacles in (1/∞ weighted region problem) and present a (1 + ∊)-factor approximation algorithm.
Model-based hierarchical clustering

We present an approach to model-based hierarchical clustering by formulating an objective function based on a Bayesian analysis. This model organizes the data into a cluster hierarchy while specifying a complex feature-set partitioning that is a key component of our model. Features can have either a unique distribution in every cluster or a common distribution over some (or even all) of the clusters. The cluster subsets over which these features have such a common distribution correspond to the nodes (clusters) of the tree representing the hierarchy. We apply this general model to the problem of document clustering for which we use a multinomial likelihood function and Dirichlet priors. Our algorithm consists of a two-stage process wherein we first perform a flat clustering followed by a modified hierarchical agglomerative merging process that includes determining the features that will have common distributions over the merged clusters. The regularization induced by using the marginal likelihood automatically determines the optimal model structure including number of clusters, the depth of the tree and the subset of features to be modeled as having a common distribution at each node. We present experimental results on both synthetic data and a real document collection.
The Race to Beat the Cuprates

Layered copper oxide (cuprate) materials have held the record for high-temperature superconductivity for more than a decade. But as Dagotto explains in his Perspective, fullerenes may soon rival the cuprates. He highlights two reports by SchA¶net al., who have used a recently developed technique to induce superconductivity both in ladder cuprates and in a doped Cmaterial. The latter shows superconductivity at temperatures of up to 117 kelvin, a record for noncuprates and close to the cuprate record of 133 kelvin. Modifications to the material may help raise the critical temperature further, possibly beyond 133 kelvin.
High gradient acceleration in a 17 GHz photocathode RF gun

A 17 GHz RF acceleration experiment is being constructed at MIT. The goal is to study particle acceleration at high field gradients and to generate high quality electron beams for potential applications in next generation linear colliders and free electron lasers. The peak accelerating gradient in the l 1/2; cavity RF gun is about 250 MV/m. The expected beam parameters, for operation with a photoemission cathode, are as follows: energy 2 MeV, normalized emittance 0.43 π mm-mrad, energy spread 0.18%, bunch charge 0.1 nC, and bunch length 0.39 ps. The detailed experimental setup, including RF cavity, RF transport and coupling, vacuum system, laser and timing system are described.
Performance of M-ary soft fusion systems using simulated human responses

A major hurdle in the development of soft and hard/soft data fusion systems is the inability to determine the practical performance gains between fusion operators without the burdens associated with human testing. Drift diffusion models of human responses (i.e., decision, confidence assessments, and response times) from cognitive psychology can be used to gain a sense of the performance of a fusion system during the design phase without the need for human testing. The majority of these models were developed for binary decision tasks, and furthermore, the few models which can operate on M-ary decision tasks are yet unable to generate subject confidence assessments. The current study proposes a method for realizing human responses over an M-ary decision task using pairwise successive comparisons of related binary decision tasks. We provide an example based on the two-stage dynamic signal detection models developed by Pleskac and Busemeyer (2010) where subjects were presented with a pair of lines on a computer screen, asked to determine which of two lines was the longest, and to assess their confidence in their decision using a subjective probability scale. M-ary human opinions were simulated for this line length task and used to assess the performance of several fusion rules, namely: Bayes' rule of probability combination, Dempster's Rule of Combination (DRC), Yager's rule, Dubois and Prade's rule (DPR), and the Proportional Conflict Redistribution rule #5. When taking source reliability into account in the combination, Bayes' rule of probability combination and DRC exhibited the most accurate performance (i.e., the largest amount of specific evidence committed towards the true outcome) for this task. Yager's rule and DPR exhibited inferior performance across all simulated cases.
Development of a tester for evaluation of prototype thermal cells and batteries

A tester was developed to evaluate prototype thermal cells and batteries-especially high-voltage units-under a wide range of constant-current and constant-resistance discharge conditions. Programming of the steady-state and pulsing conditions was by software control or by hardware control via an external pulse generator. The tester was assembled from primarily Hewlett-Packard (H-P) instrumentation and was operated under H-P's Rocky Mountain Basic (RMB). Constant-current electronic loads rated up to 4 kW (400 V at up to 100 A) were successfully used with the setup. For testing under constant-resistance conditions, power metal-oxide field-effect transistors (MOSFETs) controlled by a programmable pulse generator were used to switch between steady-state and pulse loads. The pulses were digitized at up to a 50 kHz rate (20 /spl mu/ s/pt) using high-speed DVMs; steady-state voltages were monitored with standard DVMs. This paper describes several of the test configurations used and discusses the limitations of each. Representative data are presented for a number of the test conditions. >
Modeling students' metacognitive errors in two intelligent tutoring systems

Intelligent tutoring systems help students acquire cognitive skills by tracing students' knowledge and providing relevant feedback. However, feedback that focuses only on the cognitive level might not be optimal – errors are often the result of inappropriate metacognitive decisions. We have developed two models which detect aspects of student faulty metacognitive behavior: A prescriptive rational model aimed at improving help-seeking behavior, and a descriptive machine-learned model aimed at eliminating attempts to “game” the tutor. In a comparison between the two models we found that while both successfully identify gaming behavior, one is better at characterizing the types of problems students game in, and the other captures a larger variety of faulty behaviors. An analysis of students' actions in two different tutors suggests that the help-seeking model is domain independent, and that students' behavior is fairly consistent across classrooms, age groups, domains, and task elements.
A novel degree of freedom in flapping wings shows promise for a dual aerial/aquatic vehicle propulsor

Ocean sampling for highly temporal phenomena, such as harmful algal blooms, necessitates a vehicle capable of fast aerial travel interspersed with an aquatic means of acquiring in-situ measurements. Vehicle platforms with this capability have yet to be widely adopted by the oceanographic community. Several animal examples successfully make this aerial/aquatic transition using a flapping foil actuator, offering an existence proof for a viable vehicle design (Fig. 1).We discuss a preliminary realization of a flapping wing actuation system for use in both air and water. The wing employs an active in-line motion degree of freedom to generate the large force envelope necessary for propulsion in both fluid media.