On the mass-luminosity relation for galaxies

Relation between neutral hydrogen mass and luminosity for spiral and irregular galaxie

Optimal control of the heave motion of marine cable subsea-unit systems

One of the key problems associated with subsea operations involving tethered subsea units is the motions of support vessels on the ocean surface which can be transmitted to the subsea unit through the cable and increase the tension. In this paper, a theoretical approach for heave compensation is developed. After proper modelling of each element of the system, which includes the cable/subsea-unit, the onboard winch, control theory is applied to design an optimal control law. Numerical simulations are carried out, and it is found that the proposed active control scheme appears to be a promising solution to the problem of heave compensation

On Measuring Consumer Welfare Effects of Trade Reform

We develop a measure of consumer welfare by approximating Hicksian compensating variation as a function of all commodity prices and compensated price elasticities. The unique feature of this approach is that all direct- and cross-commodity effects of a demand system are incorporated into the welfare measurement. This approach is useful for developing an instrumental model to evaluate the consumer welfare effects of trade reform. For illustration, the proposed procedure is applied to Taiwan's meat industry, and various scenarios are considered to show the effects of eliminating meat tariff rates on the quantities of meat demanded and on the savings of meat expenditures.Consumer/Household Economics, International Relations/Trade,

How Increased Food and Energy Prices Affect Consumer Welfare

We analyze the consumer welfare effects of increased food and energy prices and find that the own-price elasticities of both food and energy are relatively inelastic, which explain well the dynamics of the recent soaring food and energy prices. The estimated demand elasticities are then used to analyze the consumer welfare effects of price changes in food and energy. The results indicate that an increase of food and energy prices would incur a substantial consumer welfare loss, which is a heavy burden for low income households.Demand elasticity, compensating variation, consumer welfare, Demand and Price Analysis,

Do Americans Change Toward Healthy Diets?

American’s nutritional and health status appear to be trending toward healthier diets, as measured by a reduction in cholesterol intake and an increase in calcium intake. The levels of food energy and total fats, however, increased substantially.Changes in American diet, nutrient economic responses, Health Economics and Policy, Poster 3601001,

MEASURING FOOD MANUFACTURING PRODUCTIVITY: GROSS- OR NET-OUTPUT APPROACH?

The measured multifactor productivity index of the value of shipments shows a trend of declining and then moving up and down along the level of the base year 1975. The influence of technological changes to the output growth is rather limited. The measured labor productivity index of the value-added exhibits a trend of steady increase over years. The contribution of the food-manufacturing sector to the growth of GDP increased during 1975-97.Food manufacturing, multifactor productivity, labor productivity, Agribusiness, Productivity Analysis,

Reactive-Coupling-Induced Normal Mode Splittings in Microdisk Resonators Coupled to Waveguides

We study the optomechanical design introduced by M. Li et al. [Phys. Rev. Lett. {\bf 103}, 223901 (2009)], which is very effective for investigation of the effects of reactive coupling. We show the normal mode splitting which is due solely to reactive coupling rather than due to dispersive coupling. We suggest feeding the waveguide with a pump field along with a probe field and scanning the output probe for evidence of reactive-coupling-induced normal mode splitting.Comment: 4 pages,6 figure

Nanomechanical Inverse Electromagnetically Induced Transparency and Confinement of Light in Normal modes

We demonstrate the existence of the phenomenon of the inverse electromagnetically induced transparency (IEIT) in an opto mechanical system consisting of a nanomechanical mirror placed in an optical cavity. We show that two weak counter-propagating identical classical probe fields can be completely absorbed by the system in the presence of a strong coupling field so that the output probe fields are zero. The light is completely confined inside the cavity and the energy of the incoming probe fields is shared between the cavity field and creation of a coherent phonon and resides primarily in one of the polariton modes. The energy can be extracted by a perturbation of the external fields or by suddenly changing the $Q$ of the cavity.Comment: 10 pages, 5 figure