Generalized Quantum Hall Projection Hamiltonians

Certain well known quantum Hall states -- including the Laughlin states, the Moore-Read Pfaffian, and the Read-Rezayi Parafermion states -- can be defined as the unique lowest degree symmetric analytic function that vanishes as at least p powers as some number (g+1) of particles approach the same point. Analogously, these same quantum Hall states can be generated as the exact highest density zero energy state of simple angular momentum projection operators. Following this theme we determine the highest density zero energy state for many other values of p and g.Comment: 9 page

A nu=2/5 Paired Wavefunction

We construct a wavefunction, generalizing the well known Moore-Read Pfaffian, that describes spinless electrons at filling fraction nu=2/5 (or bosons at filling fraction nu=2/3) as the ground state of a very simple three body potential. We find, analogous to the Pfaffian, that when quasiholes are added there is a ground state degeneracy which can be identified as zero-modes of the quasiholes. The zero-modes are identified as having semionic statistics. We write this wavefunction as a correlator of the Virasoro minimal model conformal field theory M(5,3). Since this model is non-unitary, we conclude that this wavefunction is a quantum critical state. Nonetheless, we find that the overlaps of this wavefunction with exact diagonalizations in the lowest and first excited Landau level are very high, suggesting that this wavefunction may have experimental relevance for some transition that may occur in that regime.Comment: 13 pages, 2 figure

Vacuum Structure of Two-Dimensional ϕ4\phi^4 Theory on the Orbifold S1/Z2S^{1}/Z_{2}

We consider the vacuum structure of two-dimensional $\phi^4$ theory on $S^{1}/Z_{2}$ both in the bosonic and the supersymmetric cases. When the size of the orbifold is varied, a phase transition occurs at $L_{c}=2\pi/m$, where $m$ is the mass of $\phi$. For $L<L_{c}$, there is a unique vacuum, while for $L>L_{c}$, there are two degenerate vacua. We also obtain the 1-loop quantum corrections around these vacuum solutions, exactly in the case of $L<L_{c}$ and perturbatively for $L$ greater than but close to $L_{c}$. Including the fermions we find that the "chiral" zero modes around the fixed points are different for $LL_{c}$. As for the quantum corrections, the fermionic contributions cancel the singular part of the bosonic contributions at L=0. Then the total quantum correction has a minimum at the critical length $L_{c}$.Comment: Revtex, 15 pages, 3 eps figure

The Proposed U.S.-South Korea Free Trade Agreement (KORUS FTA): Provisions and Implications

[Excerpt] On June 30, 2007, U.S. and South Korean trade officials signed the proposed U.S.-South Korean Free Trade Agreement (KORUS FTA) for their respective countries. If approved, the KORUS FTA would be the second-largest FTA that South Korea has signed to date, after the agreement with the European Union (EU). It would be the second-largest (next to North American Free Trade Agreement, NAFTA) in which the United States participates. South Korea is the seventhlargest trading partner of the United States and the United States is South Korea’s third-largest trading partner. Various studies conclude that the agreement would increase bilateral trade and investment flows. The final text of the proposed KORUS FTA covers a wide range of trade and investment issues and, therefore, could have substantial economic implications for both the United States and South Korea. The agreement will not enter into force unless Congress approves implementation legislation. The negotiations were conducted under the trade promotion authority (TPA), also called fast-track trade authority, that Congress granted the President under the Bipartisan Trade Promotion Act of 2002 (P.L. 107-210). Under TPA the President has the discretion on when to submit the implementing legislation to Congress. President Bush did not submit the legislation because of differences with the Democratic leadership over treatment of autos and beef, among other issues. Early in his Administration, President Obama indicated the need to resolve those issues before he would submit the implementing legislation. On December 3, 2010, after a series of arduous negotiations and missed deadlines, President Obama and President Lee announced that their negotiators reached agreement on modifications in the KORUS FTA, and that they were prepared to move ahead to getting the agreement approved by the respective legislatures. The White House is expected to send implementing legislation to the 112th Congress and that it would like to see Congress approve the agreement by July 1 of this year. The modifications are in the form of changes in phase-out periods for tariffs on autos, a new safeguard provision on autos, and concessions by South Korea on allowing a larger number of U.S. cars into South Korea under U.S. safety standards than was the case under the original KORUS FTA provisions. The issue of full U.S. beef access was not resolved because of the political sensitivity of the issue in South Korea. In 2008, when President Lee reached a separate agreement with the United States to lift South Korea’s ban on U.S. beef imports, massive anti-South Korean government protests forced the two governments to renegotiate its terms. The U.S. beef sector has largely supported the KORUS FTA. A broad swath of the U.S. business community supports the KORUS FTA . With the modifications in the agreement reached in December, this group also includes the three Detroit-based auto manufacturers and the United Auto Workers (UAW) union. It still faces opposition from some labor unions and other groups, including Public Citizen. Many U.S. supporters view passage of the KORUS FTA as important to secure new opportunities in the South Korean market, while opponents claim that the KORUS FTA does not go far enough to break down South Korean trade barriers or that the agreement will encourage U.S. companies to move their production offshore at the expense of U.S. workers. Other observers have suggested the outcome of the KORUS FTA could have implications for the U.S.-South Korean alliance as a whole, as well as on U.S. Asia policy and U.S. trade policy, particularly in light of an FTA signed in by South Korea and the EU that is expected to go into effect on July 1, 2011

The EU-South Korea Free Trade Agreement and Its Implications for the United States

[Excerpt] On October 6,2010, the 27 member European Union (EU) and South Korea signed a bilateral free trade agreement (FTA). The agreement is expected to go into effect on July 1, 2011, pending approval by the European Parliament and the South Korean National Assembly. If enacted, the South Korea-EU FTA (KOREU FTA) would be the largest FTA in terms of market size that South Korea has entered into. The KOREU FTA reflects the EU and South Korean trade strategies to use FTAs to strengthen economic ties outside their home regions. It also builds upon the surge in trade and investment flows between South Korea and the EU over the past decade. This agreement has possible implications for U.S. trade with South Korea and congressional action on the proposed U.S.-South Korea FTA (KORUS FTA). The proposed KOREU FTA is very comprehensive. It would reduce and eliminate tariffs and other trade barriers in manufactured goods, agricultural products and services and would also cover such trade-related activities as government procurement, intellectual property rights, labor rights and environmental issues. Most studies done on the potential impact of the KOREU FTA estimate that the agreement will have a small but positive effect on the economies of the EU and South Korea as a whole and that the larger relative impact would be on the South Korean economy. The greatest economic impact of the KOREU FTA would be on specific sectors in each economy. EU services providers would be expected to experience gains from the agreement, especially in the areas of retail and wholesale trade, transportation services, financial services, and business services. In terms of trade in goods, EU exporters of pharmaceuticals, auto parts, industrial machinery, electronics parts, and some agricultural goods and processed foods would be expected to gain from the KOREU FTA\u27s implementation. At the same time, South Korean manufacturers of cars, ships, wireless telecommunications devices, chemical products, and imaging equipment would be expected to increase their exports to the EU market. The KOREU FTA is similar to the proposed KORUS FTA in many respects. Both agreements are comprehensive and both would eliminate tariffs on most trade in goods soon after they enter into force. However, they differ in other respects. Phase-out periods for tariffs on some manufactured goods differ. In addition, the KOREU FTA does not cover foreign direct investment. Unlike the KORUS FTA, the KOREU FTA would not allow trade sanctions to be applied where violations of the workers\u27 rights, and environment provisions have been deemed to occur. In addition, the KORUS FTA would cover a broader range of trade in services than would the KOREU FTA. It is not clear whether these differences in the structures of the FTAs would result in appreciable differences in outcomes in terms of economic gains and losses. U.S. and European firms are close competitors in a number of sectors and industries, particularly autos. Some business representatives argue that enactment of the KOREU FTA before enactment of the KORUS FTA would give European competitors commercial first mover advantages, since EU firms, such as those in the auto industry or the services sector, could gain greater market opportunities in South Korea not afforded to US. firms. On the other hand, other factors could also mitigate such advantages. For example, U.S. multinational firms operating in the EU could benefit from the KOREU FTA. Nevertheless, the content and fate of the KOREU FTA could influence the pace and tone of any debate in the United States on the KORUS FTA in the 112th Congress

Machine learning with the hierarchy‐of‐hypotheses (HoH) approach discovers novel pattern in studies on biological invasions

Research synthesis on simple yet general hypotheses and ideas is challenging in scientific disciplines studying highly context‐dependent systems such as medical, social, and biological sciences. This study shows that machine learning, equation‐free statistical modeling of artificial intelligence, is a promising synthesis tool for discovering novel patterns and the source of controversy in a general hypothesis. We apply a decision tree algorithm, assuming that evidence from various contexts can be adequately integrated in a hierarchically nested structure. As a case study, we analyzed 163 articles that studied a prominent hypothesis in invasion biology, the enemy release hypothesis. We explored if any of the nine attributes that classify each study can differentiate conclusions as classification problem. Results corroborated that machine learning can be useful for research synthesis, as the algorithm could detect patterns that had been already focused in previous narrative reviews. Compared with the previous synthesis study that assessed the same evidence collection based on experts' judgement, the algorithm has newly proposed that the studies focusing on Asian regions mostly supported the hypothesis, suggesting that more detailed investigations in these regions can enhance our understanding of the hypothesis. We suggest that machine learning algorithms can be a promising synthesis tool especially where studies (a) reformulate a general hypothesis from different perspectives, (b) use different methods or variables, or (c) report insufficient information for conducting meta‐analyses

Incompressible liquid state of rapidly-rotating bosons at filling factor 3/2

Bosons in the lowest Landau level, such as rapidly-rotating cold trapped atoms, are investigated numerically in the specially interesting case in which the filling factor (ratio of particle number to vortex number) is 3/2. When a moderate amount of a longer-range (e.g. dipolar) interaction is included, we find clear evidence that the ground state is in a phase constructed earlier by two of us, in which excitations possess non-Abelian statistics.Comment: 5 pages, 5 figure

Retrospective studies of operating problems in air transport

An epidemiological model for the study of human errors in aviation is presented. In this approach, retrospective data are used as the basis for formulation of hypotheses as to system factors which may have contributed to such errors. Prospective experimental studies of aviation operations are also required in order to prove or disprove the hypotheses, and to evaluate the effectiveness of intervention techniques designed to solve operational problems in the aviation system