The complexity of lattice knots

AbstractA family of polygonal knots Kn on the cubical lattice is constructed with the property that the quotient of length L(Kn) over the crossing number Cr(Kn) approaches zero as L approaches infinity. More precisely Cr(Kn) = O(L(Kn)43). It is shown that this construction is optimal in the sense that for any knot K on the cubical lattice with length L and Cr crossings Cr ⩽ 3.2L43

Softening the Impact of Adjustment to Reform: The China Experience

This paper examines the structural adjustments induced as China moved from a planned economy that subsidized capital-intensive industry at the expense of agriculture to a nationally integrated market economy more fitting with China's underlying resource endowments. We argue that there were few losers in the process because of 1) a gradual implementation process that maintained transfers to the favored groups under the planned economy, such as urban industrial workers, while the market economy developed benefiting the non-favored groups, such as farmers; 2) high growth rates allowed a large portion of the economy to benefit from the overall reform process and bolstered the government's commitment to further reform; and 3) labor, the most important resource that farm households hold in China, was much less institutionally constrained than land and capital during the reform period, allowing rural workers to participate in the fast growing nonagricultural sector.Agricultural and Food Policy, Political Economy,

Forces behind China's Surging Trade: Competitiveness or Policy Driven?

This paper delves into China's differential growths in trade flows with high income countries by focusing on bilateral content of trade data over the time period 1962-2005. Unlike other studies, we account for end use of traded goods ranging from primary, intermediate, and finished goods because China's policies impact all segments China's trade flows. China's trade growth patterns with major high income countries clearly indicate that the adjacency-neighborhood partners alone is unlikely to explain its unprecedented growth in exports and imports. China's outstanding performance in trade growth can be traced back to the 1970s with changes in its policies and increased involvement in the international segmentation of production processes and preferential tariff treatment to assembling and processing activities.China, international trade, growth, policies, International Relations/Trade,

Developing Country Trade: Implications of China’s Changing Trade and Competitiveness in Intensive and Extensive Margin Goods

This paper delves into China’s differential growths in trade flows with high income and developing countries by focusing on bilateral content of trade data over the time period 1978-2005. Unlike other studies, we account for end use of traded goods ranging from primary, intermediate, and finished goods because China’s policies impact all segments China’s trade flows. In the last 28 years, China has specialized in deficits in the upstream production segments (parts and components) and rapid diversification in consumption goods (extensive margin). While in the late 1970s China’s export and import growth on all goods with major high income countries is outstanding in the most recent years China’s trade growth with developing countries has taken the lead while China is gaining in extensive margins goods trade. This general pattern evolving is in agreement with some of the new trade theory that gives a dominant role to an expansion of the number of export varieties (the extensive margin), which provides an additional channel for welfare gains from trade.China, international trade, growth, intensive, extensive margins, developing countries, International Relations/Trade,

Functional characterization of a gluthathione Stransferase gene from Limonium bicolor in response to several abiotic stresses

In the present study, we characterized a gluthathione S-transferase gene (LbGST1) in response to different abiotic stresses. Real time polymerase chain reaction (RT-PCR) indicated that the LbGST1 can be differentially regulated by stress of NaCl, NaHCO3 and low temperature, suggesting a role in plant stress response. To further investigate abiotic stress tolerance of LbGST1, the transgenic yeast harboring the LbGST1 was generated under the control of inducible GAL promoter (pYES2 vector); yeast cells transformed with empty pYES2 were also generated as a control. Stress tolerance tests showed that LbGST1 yeast transformants exhibited elevated tolerance to the stresses of thermal (53°C), alkali (NaHCO3), ultraviolet radiation, salt (NaCl), drought (sorbitol) and freezing (-20°C) compared with the control transformants, suggesting that the LbGST1 is tolerant to these abiotic stresses. Our results indicate that the LbGST1 gene is resistant to a wider repertoire of stresses and may play a common role in plant acclimation to the examined stress conditions.Key words: Gluthathione S-transferases (GST), abiotic stress, expression analysis, Limonium bicolor

Thermo-mechanical sensitivity calibration of nanotorsional magnetometers

We report on the fabrication of sensitive nanotorsional resonators, which can be utilized as magnetometers for investigating the magnetization dynamics in small magnetic elements. The thermo-mechanical noise is calibrated with the resonator displacement in order to determine the ultimate mechanical torque sensitivity of the magnetometer.Comment: 56th Annual Conference on Magnetism and Magnetic Material

Generalized Random Utility Models with Multiple Types

We propose a model for demand estimation in multi-agent, differentiated product settings and present an estimation algorithm that uses reversible jump MCMC techniques to classify agents' types. Our model extends the popular setup in Berry, Levinsohn and Pakes (1995) to allow for the data-driven classification of agents' types using agent-level data. We focus on applications involving data on agents' ranking over alternatives, and present theoretical conditions that establish the identifiability of the model and uni-modality of the likelihood/posterior. Results on both real and simulated data provide support for the scalability of our approach.EconomicsEngineering and Applied SciencesMathematic

A new DC micro-grid system using renewable energy and electric vehicles for smart energy delivery

This paper proposes a new DC micro-grid system, which fully utilizes the renewable energy and electric vehicle for smart energy delivery. The proposed DC grid incorporates the AC supply module, standby energy module, renewable energy module, and storage energy module together, to execute the energy distribution. Hence, this grid system can offer a high quality power for the three types of loads, namely 110V AC single-phase output, 48V DC output, and 100V DC output. The control strategy of the grid system for performing smart energy delivery will be discussed in the full paper. The simulation results will be also given to verify the four operation modes of the grid system.published_or_final_versionThe 2010 IEEE Vehicle Power and Propulsion Conference (VPPC), Lille, France, 1-3 September 2010. In Proceedings of VPPC, 2010, p. 1-

Measured Constraints on Cloud Top Entrainment to Reduce Uncertainty of Nonprecipitating Stratocumulus Shortwave Radiative Forcing in the Southern Ocean

Stratocumulus cloud top entrainment has a significant effect on cloud properties, but there are few observations quantifying its impact. Using explicit 0-D parcel model simulations, initialized with below-cloud in situ measurements, and validated with in situ measurements of cloud properties, the shortwave cloud radiative forcing (SWCF) was reduced by up to 100 W m−2 by cloud top entrainment in the Southern Ocean. The impact of entrainment-corrected SWCF is between 2 and 20 times that of changes in the aerosol particle concentration or updraft at cloud base. The variability in entrainment-corrected SWCF accounts for up to 50 W m−2 uncertainty in estimating cloud forcing. Measurements necessary for estimating the impact of entrainment on cloud properties can be constrained from existing airborne platforms and provide a first-order approximation for cloud radiative properties of nonprecipitating stratocumulus clouds. These measurement-derived estimates of entrainment can be used to validate and improve parameterizations of entrainment in Global Climate Models