8,121 research outputs found

    Benefit Evaluation of the Country of Origin Labeling in Taiwan: Results from Auction Experiment

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    This research is aimed at investigating the consumer’s preference for food produced in Taiwan and the economic benefits for the country of origin labeling. The study uses both experimental auction and contingent valuation method (CVM) to investigate factors that affect the consumer’s willingness to pay (WTP) for products under country-of-origin labeling (COOL). Experimental auctions of Taiwan and China preserved olives as well as Taiwan, China and Vietnam oolong teas were conducted using the Vickrey’s second price sealed bid auction. For CVM, the study used the double-bounded dichotomous choice method in which we started assuming the same base price for all products in the first question and then varied the prices in the second CV question. The products not chosen in the first question were offered with a discount in a range from 10% to 50% in the following question. Based on auction data, the Tobit model shows that the estimated premiums are 58.1%, 78.15% and 98.13% for Taiwan products over their alternatives of China olives, China oolong tea, and Vietnam oolong tea, respectively. Based on the CVM, the estimated premiums for Taiwan over China olives from a Logit model is 67%, and the premiums for Taiwan produced oolong tea should lie between 50% to an unknown upper bound over China and Vietnam alternatives as the Multinomial Logit model cannot be successfully estimated due to too few choice switches with discounted prices. The study thus demonstrates the superiority of the experimental auction over the CVM in eliciting the WTP for foods produced in Taiwan. The study concludes that enacting a COOL law would increase economic benefits to consumers in Taiwan, and at the same time, placing the imported products in the level playing field.country-of-origin labeling, experimental auction, Tobit model, contingent valuation method, logit model, multinomial logit model, willingness to pay, Agricultural and Food Policy, Consumer/Household Economics, Demand and Price Analysis, Food Consumption/Nutrition/Food Safety, Q13, D12.,

    Decomposing non-product form queueing lattices through autorouting with A* algorithm

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    Direct solution techniques are expensive for the state transition lattice of a class of non-product form queuing modes. In this thesis, Autorouting with A* algorithm is adapted to decompose it as solvable subsets which can be solved sequentially and independently. Autorouting with A* algorithm is heuristics in problem solving. It also is one of a class of global optimization problems that are difficult to solve. Some queuing modes of type A will be decomposed in this thesis through Autorouting with A* algorithm

    Real-time Feedback of B0 Shimming at Ultra High Field MRI

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    Magnetic resonance imaging(MRI) is moving towards higher and higher field strengths. After 1.5T MRI scanners became commonplace, 3T scanners were introduced and once 3T scanners became commonplace, ultra high field (UHF) scanners were introduced. UHF scanners typically refer to scanners with a field strength of 7T or higher. The number of sites that utilise UHF scanners is slowly growing and the first 7T MRI scanners were recently CE certified for clinical use. Although UHF scanners have the benefit of higher signal-to-noise ratio (SNR), they come with their own challenges. One of the many challenges is the problem of inhomogeneity of the main static magnetic field(B0 field). This thesis addresses multiple aspects associated with the problem of B0 inhomogeneity. The process of homogenising the field is called "shimming". The focus of this thesis is on active shimming where extra shim coils drive DC currents to generate extra magnetic fields superimposed on the main magnetic field to correct for inhomogeneities. In particular, we looked at the following issues: algorithms for calculating optimal shim currents; global static shimming using very high order/degree spherical harmonic-based (VHOS) coils; dynamic slice-wise shimming using VHOS coils compared to a localised multi-coil array shim system; B0 field monitoring using an NMR field camera; characterisation of the shim system using a field camera; and designing a controller based on the shim system model for real-time feedback
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