Chaotic temperature dependence in a model of spin glasses

We address the problem of chaotic temperature dependence in disordered glassy systems at equilibrium by following states of a random-energy random-entropy model in temperature; of particular interest are the crossings of the free-energies of these states. We find that this model exhibits strong, weak or no temperature chaos depending on the value of an exponent. This allows us to write a general criterion for temperature chaos in disordered systems, predicting the presence of temperature chaos in the Sherrington-Kirkpatrick and Edwards-Anderson spin glass models, albeit when the number of spins is large enough. The absence of chaos for smaller systems may justify why it is difficult to observe chaos with current simulations. We also illustrate our findings by studying temperature chaos in the naive mean field equations for the Edwards-Anderson spin glass.Comment: 10 pages, 5 figures; To be published in European Physics Journal

International Trade: Rules of Origin

[Excerpt] Determining the country of origin of a product is important for properly assessing tariffs, enforcing trade remedies (such as anti-dumping and countervailing duties) or quantitative restrictions (tariff quotas), and statistical purposes. Other commercial trade policies are also linked with origin determinations, such as country of origin labeling and government procurement regulations. Rules of origin (ROO), used to determine the country of origin of merchandise entering the U.S. market, can be very simple, noncontroversial tools of international trade as long as all of the parts of a product are manufactured and assembled primarily in one country. However, when a finished product’s component parts originate in many countries, as is often the case in today’s global trading environment, determining origin can be a very complex, sometimes subjective, and time-consuming process. U.S. Customs and Border Protection (CBP) is the agency responsible for determining country of origin using various ROO schemes. Non-preferential rules of origin are used to determine the origin of goods imported from countries with which the United States has most-favored-nation (MFN) status. They are the principal regulatory tools for accurate assessment of tariffs on imports, addressing country of origin labeling issues, qualifying goods for government procurement, and enforcing trade remedy actions and trade sanctions. Preferential rules are used to determine the eligibility of imported goods from certain U.S. free trade agreement (FTA) partners and certain developing country beneficiaries to receive duty-free or reduced tariff benefits under bilateral or regional FTAs, trade preference programs (such as the Generalized System of Preferences), and other special import programs. Preferential rules of origin are specific to each FTA, which means that they vary from agreement to agreement and preference to preference. This report deals with ROO in three parts. First, we describe in more detail the reasons that country of origin rules are important and briefly describe U.S. laws and methods that provide direction in making these determinations. Second, we discuss briefly some of the more controversial issues involving rules of origin, including the apparently subjective nature of some CBP origin determinations, and the effects of the global manufacturing process on ROO. Third, we conclude with some alternatives and options that Congress could consider that might assist in simplifying the process. This report will be updated as events warrant

Measuring the Higgs to Photon-Photon Branching Ratio at the Next Linear e+e−e^+e^- Collider

We examine the prospects for measuring the photon-photon branching ratio of a Standard-Model-like Higgs boson ($h$) at the Next Linear $e^+e^-$ Collider when the Higgs boson is produced via $W^+W^-$--fusion: $e^+e^-\to\nu_e \bar\nu_e h$. In particular, we study the accuracy of such a measurement and the statistical significance of the associated signal as a function of the electromagnetic calorimeter resolution and the Higgs boson mass. We compare results for the $W^+W^-$--fusion production/measurement mode with the results obtained for the $e^+e^-\rightarrow Z^*\rightarrow Z h$ production/measurement mode in a parallel earlier study.Comment: 5 pages, full postscript file also available via anonymous ftp at ftp://ucdhep.ucdavis.edu/gunion/htogamgam_sm96.ps To appear in ``Proceedings of the 1996 DPF/DPB Summer Study on New Directions for High Energy Physics'

Higher covariant derivative regulators and non-multiplicative renormalization

The renormalization algorithm based on regularization methods with two regulators is analyzed by means of explicit computations. We show in particular that regularization by higher covariant derivative terms can be complemented with dimensional regularization to obtain a consistent renormalized 4-dimensional Yang-Mills theory at the one-loop level. This shows that hybrid regularization methods can be applied not only to finite theories, like \eg\ Chern-Simons, but also to divergent theories.Comment: 12 pages, phyzzx, no figure

Global differential geometry: An introduction for control engineers

The basic concepts and terminology of modern global differential geometry are discussed as an introduction to the Lie theory of differential equations and to the role of Grassmannians in control systems analysis. To reach these topics, the fundamental notions of manifolds, tangent spaces, vector fields, and Lie algebras are discussed and exemplified. An appendix reviews such concepts needed for vector calculus as open and closed sets, compactness, continuity, and derivative. Although the content is mathematical, this is not a mathematical treatise but rather a text for engineers to understand geometric and nonlinear control

Combined high vacuum/high frequency fatigue tester

Apparatus permits application of significantly greater number of cycles or equivalent number of cycles in shorter time than conventional fatigue test machines. Environment eliminates problems associated with high temperature oxidation and with sensitivity of refractory alloy behavior to atmospheric contamination

SEAHT: A computer program for the use of intersecting arcs of altimeter data for sea surface height refinement

The SEAHT program is designed to process multiple passes of altimeter data with intersecting ground tracks, with the estimation of corrections for orbital errors to each pass such that the data has the best overall agreement at the crossover points. Orbit error for each pass is modeled as a polynomial in time, with optional orders of 0, 1, or 2. One or more passes may be constrained in the adjustment process, thus allowing passes with the best orbits to provide the overall level and orientation of the estimated sea surface heights. Intersections which disagree by more than an input edit level are not used in the error parameter estimation. In the program implementation, passes are grouped into South-North passes and North-South passes, with the North-South passes partitioned out for the estimation of orbit error parameters. Computer core utilization is thus dependent on the number of parameters estimated for the set of South-North arcs, but is independent on the number of North-South passes. Estimated corrections for each pass are applied to the data at its input data rate and an output tape is written which contains the corrected data

International Trade: Rules of Origin

[Excerpt] Recent trade policy issues have pointed to the framework used by the United States and other countries to regulate imports, including the process of determining country of origin using “rules of origin” (ROO). Such rules can be very simple, noncontroversial tools of international trade as long as all of the parts of a product are manufactured and assembled primarily in one country. However, when a finished product’s component parts originate in many countries—as is often the case in today’s global trading environment—determining origin can be a very complex, sometimes subjective, and time-consuming process. This report first provides a general overview of the U.S. ROO system, including its implementation as it applies to manufactured imports. Second, advantages and disadvantages of the ROO schemes as implemented by the United States are also discussed. Third, the report illustrates ways in which the application of the rules of origin system can lead to country of origin determinations that could be inconsistent with U.S. policy objectives or goals, or encourage businesses to circumvent them. The report concludes with some options that Congress could consider in order to improve the ROO process

Higher covariant derivative Pauli-Villars regularization does not lead to a consistent QCD

We compute the beta function at one loop for Yang-Mills theory using as regulator the combination of higher covariant derivatives and Pauli-Villars determinants proposed by Faddeev and Slavnov. This regularization prescription has the appealing feature that it is manifestly gauge invariant and essentially four-dimensional. It happens however that the one-loop coefficient in the beta function that it yields is not $-11/3,$ as it should be, but $-23/6.$ The difference is due to unphysical logarithmic radiative corrections generated by the Pauli-Villars determinants on which the regularization method is based. This no-go result discards the prescription as a viable gauge invariant regularization, thus solving a long-standing open question in the literature. We also observe that the prescription can be modified so as to not generate unphysical logarithmic corrections, but at the expense of losing manifest gauge invariance.Comment: 43 pages, Latex file (uses the macro axodraw.sty, instructions of how to get it and use it included), FTUAM 94/9, NIKHEF-H 94/2