Real convergence and regime-switching among EU accession countries

Real convergence among the ten EU 2004 accession economies is investigated with respect to long-run real interest parity. We employ a novel approach where unit-root tests for real interest differentials are embedded within a Markov regime-switching framework. Whereas standard univariate unit-root tests provide mixed support for parity, we find parity is present in all cases where differentials either switch between regimes of stationary and non-stationarity behaviour, or between alternative regimes of stationarity characterized by differing degrees of persistence. Further insights are obtained from the inferred probabilities of being in each regime, and the regime-switching nature of the differential variances

Strong transmission and reflection of edge modes in bounded photonic graphene

The propagation of linear and nonlinear edge modes in bounded photonic honeycomb lattices formed by an array of rapidly varying helical waveguides is studied. These edge modes are found to exhibit strong transmission (reflection) around sharp corners when the dispersion relation is topologically nontrivial (trivial), and can also remain stationary. An asymptotic theory is developed that establishes the presence (absence) of edge states on all four sides, including in particular armchair edge states, in the topologically nontrivial (trivial) case. In the presence of topological protection, nonlinear edge solitons can persist over very long distances.Comment: 5 pages, 4 figures. Minor updates on the presentation and interpretation of results. The movies showing transmission and reflection of linear edge modes are available at https://www.youtube.com/watch?v=XhaZZlkMadQ and https://www.youtube.com/watch?v=R8NOw0NvRu

Circular 66

Phosphorus (P) along with nitrogen (N) and potassium (K) comprise the three macronutrients most frequently added as fertilizer for growing plants. In Alaska soils, P is often the second most limiting nutrient after N. A proper supply of plant-available P is important for root development and plant growth. To supply P to growing crops, the soil not only must contain enough P, but it must be in a form which is available for utilization by the plant. The status of P in the soil has an important influence on fertilization practices. Agricultural soils of Alaska vary considerably, not only in their total content of P and its distribution (form it occurs in), but also in the characteristics for sorption or fixation of P (Ping and Michaelson, 1986). Forms of P in the soil will affect its availability. The P-sorption character of soils will affect P fertilizer reactions in the soil and thus influence the amount of P fertilizer necessary and carry-over effects of applied P. It is essential that P soil tests and their interpretation be tailored for soils with similar P reactions. A useful P soil test must be based on both correlation of test values to plant growth and to field calibration of soil test values with yield

Characteristics and Fertility Status of Soils and Minesoils in Selected Areas of Usibelli Coal Mine, Healy, Alaska

Alaska has been proven to contain not only bountiful oil and gas reserves. but also vast coal fields occurring from the southcentral coastline to the Interior and the Arctic zone to the north. Because of concerns for stable sources of energy, particularly by the energy-short, industrial nations of the Orient, more exploration and stripmining for coal can be expected in the near future. Therefore, it is important to know the consequences of large-area soil disturbances tn the subarctic and bow the effects of man's reclamation efforts and natural processes combine in reestablishing vegetative community. The culmination or synthesis of these processes is soil development and is of great importance in successful stripmine reclamation. The Usibelli Coal Mine Company in the Healy coal field, located in Interior Alaska. commenced stripmining in 1943. Its operation has been continuous, moving from area to area, for the last 40 years. Stripmining requires the excavation of overburden and subsequent redeposition, therefore the Healy operation has exposed minespoils from different strata on various topography. In 1972, the Usibelli Coal Mine company initiated a reclamation program and, over the ensuing l0 years, has seeded and fertilized over 2000 acres. Nevertheless, there remain barren areas and areas undergoing natural revegetation. Additionally, experimental trials in seeding and fertilization were started in 1980. Large areas of intact native plant communities adjoin the mined areas. The company property provides opportunities to study the processes of soil formation under different sets of conditions. The objectives of this study were to (1) characterize the soils on the mine lease area for baseline data, (2) to characterize the mine soils with various history, (3) to study the process of soil formation under different sets of conditions, and (4) to evaluate the nutrient levels of both soil and minesoils to form a basis for establishing soil-handling requirements to promote reclamation practices.This study was supported by funds from the U.S. Department of Energy (AM06-76RL02229) and the U.S. Department of Agriculture Hatch project. Our appreciation to Drs. W.M. Mitchell. G.A. Mitchell. and F. Wooding of the Agricultural and Forestry Experiment Station. and Mr. J.P. Moore of USDA Son Conservation Service for reviewing the manuscript and offering many useful suggestions. Our appreciation also to Dr. Milton A. Wiltse of Division of Geological and Geophysical Surveys. Department of Natural Resources for access to the X-ray diffractometer and technical advice. Special thanks to the Usibelli Coal Mine Inc. for logistic and technical assistance tn carrying out this study

Exploiting Channel Memory for Multi-User Wireless Scheduling without Channel Measurement: Capacity Regions and Algorithms

We study the fundamental network capacity of a multi-user wireless downlink under two assumptions: (1) Channels are not explicitly measured and thus instantaneous states are unknown, (2) Channels are modeled as ON/OFF Markov chains. This is an important network model to explore because channel probing may be costly or infeasible in some contexts. In this case, we can use channel memory with ACK/NACK feedback from previous transmissions to improve network throughput. Computing in closed form the capacity region of this network is difficult because it involves solving a high dimension partially observed Markov decision problem. Instead, in this paper we construct an inner and outer bound on the capacity region, showing that the bound is tight when the number of users is large and the traffic is symmetric. For the case of heterogeneous traffic and any number of users, we propose a simple queue-dependent policy that can stabilize the network with any data rates strictly within the inner capacity bound. The stability analysis uses a novel frame-based Lyapunov drift argument. The outer-bound analysis uses stochastic coupling and state aggregation to bound the performance of a restless bandit problem using a related multi-armed bandit system. Our results are useful in cognitive radio networks, opportunistic scheduling with delayed/uncertain channel state information, and restless bandit problems.Comment: 17 pages, 8 figures. Submitted to IEEE Transactions on Information Theory. The whole paper is revised and the title is changed for better clarification

Evaluation of surface energy and radiation balance systems for FIFE

The energy balance and radiation balance components were determined at six sites during the First International Satellite Land Surface Climatology Project Field Experiment (FIFE) conducted south of Manhattan, Kansas during the summer of 1987. The objectives were: to determine the effect of slope and aspect, throughout a growing season, on the magnitude of the surface energy balance fluxes as determined by the Energy Balance Method (EBM); to investigate the calculation of the soil heat flux density at the surface as calculated from the heat capacity and the thermal conductivity equations; and to evaluate the performance of the Surface Energy and Radiation Balance System (SERBS). A total of 17 variables were monitored at each site. They included net, solar (up and down), total hemispherical (up and down), and diffuse radiation, soil temperature and heat flux density, air and wet bulb temperature gradients, wind speed and direction, and precipitation. A preliminary analysis of the data, for the season, indicate that variables including net radiation, air temperature, vapor pressure, and wind speed were quite similar at the sites even though the sites were as much as 16 km apart and represented four cardinal slopes and the top of a ridge

Implementing efficient allocations in a model of financial intermediation

In a finite-trader version of the Diamond-Dybvig (1983) model, the symmetric, ex-ante efficient allocation is implementable by a direct mechanism (i.e., each trader announces the type of his own ex-post preference) in which truthful revelation is the strictly dominant strategy for each trader. When the model is modified by formalizing the sequential-service constraint (cf. Wallace, 1988), the truth-telling equilibrium implements the symmetric, ex-ante efficient allocation with respect to iterated elimination of strictly dominated strategies.Econometric models

Diamond and Dybvig's classic theory of financial intermediation : what's missing?

The article shows that in a finite-trader version of the Diamond and Dybvig model (1983), the ex ante efficient allocation can be implemented as a unique equilibrium. This is so even in the presence of the sequential service constraint, as emphasized by Wallace (1988), whereby the bank must solve a sequence of maximization problems as depositors contact it at different times. A three-trader example with constant relative risk-aversion utility is used in order to illustrate clearly the requirements that the sequential service constraint imposes on implementation.Bank failures

Generating entanglement between microwave photons and qubits in multiple cavities coupled by a superconducting qutrit

We discuss how to generate entangled coherent states of four \textrm{microwave} resonators \textrm{(a.k.a. cavities)} coupled by a superconducting qubit. We also show \textrm{that} a GHZ state of four superconducting qubits embedded in four different resonators \textrm{can be created with this scheme}. In principle, \textrm{the proposed method} can be extended to create an entangled coherent state of $n$ resonators and to prepare a Greenberger-Horne-Zeilinger (GHZ) state of $n$ qubits distributed over $n$ cavities in a quantum network. In addition, it is noted that four resonators coupled by a coupler qubit may be used as a basic circuit block to build a two-dimensional quantum network, which is useful for scalable quantum information processing.Comment: 13 pages, 7 figure