IMPACTS OF INCOME CHANGES AND MODEL SPECIFICATION ON FOOD DEMAND IN URBAN CHINA

Functional form specification is a crucial task in demand analysis. Four food demand systems for 12 aggregated food items in urban China are estimated and compared using province level data for the period 1992-1999. The results show the expenditure elasticities especially for grain are different based on the functional form selection. According to the measures of forecasting accuracy, we conclude the following: for ex post simulation, the simpler the models, the better the performances, whereas for ex ante forecasting, the more complicated the model, the better the predictions. We further conclude that the LES and QES outperform the LA/AIDS and AIDS. Therefore, model selection should depend on the study purpose. In addition, as urban Chinese household income increases, they will consume more aquatic products, poultry and milk than other foods. This potential trend will certainly benefit the fishery and livestock industries as well as feed grain producers in China or other countries such as Taiwan. However, high own-price elasticities of these three food groups suggest that the profitability of suppliers and traders is very sensitive to price changes.Demand and Price Analysis,

FOOD DEMAND IN URBAN CHINA: AN APPLICATION OF A MULTI-STAGE CENSORED DEMAND SYSTEM

Since its economic reform, China has changed significantly as it makes its transition from a centrally-planned to a consumer-oriented economy and thus has gradually increased household income and changed consumption patterns in urban China. This study attempts to provide an in-depth understanding of heterogeneous consumer patterns in urban China by developing a multi-stage censored demand system using household data. Specifically, this study develops an economic model considering heterogeneous consumption patterns across households and commodity groupings and estimates econometric models of a Quadratic Almost Ideal Demand System (QAIDS) using household data. Three methodologies are integrated including constructing a multi-stage demand system, incorporating demographic variables using the 'ordinary budget share scaling and translation' (OBSSAT), and employing a two-step estimator to deal with zero consumption problems. This study covers three provinces in China, Shandong, Jiangsu, and Guangdong, and uses household data from 1998 provided by the National Bureau of Statistics (NBS). Based on the Chinese food guide pyramid, a three-level utility tree is constructed dividing 18 food items into five subgroups. An empirical analysis is conducted by estimating econometric models to examine the impact of the potential factors, e.g., income and demographic variables, on food demand. The results show the uniqueness of this study in three dimensions. First, using the OBSSAT helps answer the question of "how to break down the heterogeneous consumption patterns in urban China?" In addition, our findings also show that China should be treated as several markets instead of one. Second, the QAIDS has not previously been applied to the study of food demand in urban China. Our results show that the QAIDS is superior to the AIDS; however, the degree of importance for the quadratic term decreases as demographic and censoring effects are considered in a demand system. Finally, 18 food items are broken down into five food subgroups and are estimated by a multi-stage censored QAIDS. Including this large food bundle in a demand system provides us detailed information of the relationship among food items.Demand and Price Analysis,

TRANSLATING AND SCALING OF BUDGET SHARES: AN EMPIRICAL ANALYSIS OF CHINESE URBAN HOUSEHOLD DEMAND FOR MEAT

The importance of incorporating demographic effects into a demand system is demonstrated using Lewbel's unified functions. In this study, the empirical analysis of meat demand in urban China shows the benefit of utilizing the translation and scaling of budget shares.Demand and Price Analysis,

A note on the connection between nonextensive entropy and hh-derivative

In order to study as a whole the major part of entropy measures, we introduce a two-parameter non-extensive entropic form with respect to the \textit{h}-derivative which generalizes the conventional Newton-Leibniz calculus. This new entropy, $S_{h,h'}$, is proved to describe the non-extensive systems and recover several types of the well-known non-extensive entropic expressions, such as the Tsallis entropy, the Abe entropy, the Shafee entropy, the Kaniadakis entropy and even the classical Boltzmann\,--\,Gibbs one. As a generalized entropy, its corresponding properties are also analyzed.Comment: 6 pages, 1 figur

Multiple-Layer Heat Dissipation Module for LED Streetlamps

[[abstract]]High-powered light-emitting diodes (LED) have rapidly developed in recent years from applications in indication devices to wider uses in illumination devices. This study proposed an innovative heat dissipation module for an LED street lamp using a number of substrates positioned in multiple-layer formation. Multi-chip LED arrays were mounted on each substrate. Heat generated by the LEDs was dissipated through a heat dissipation plate formed by the substrates, which connected to heat pipes and a heat sink. This study used several simulation models to determine the natural convection properties of the proposed module. Based on the simulations, a heat dissipation module was manufactured. Module temperatures were measured and compared with simulation results at input powers of 120 and 180W. Illuminance tests were also conducted to verify the performance of the LED lamp. The multiple-layer substrates were shown to instantly and effectively dissipate heat outward and prevent degradation in the illumination quality of the LED lamp.[[notice]]補正完畢[[incitationindex]]EI[[booktype]]紙

Thermal Performance of a Loop Thermosyphon

100學年度研究獎補助論文[[abstract]]Experimental investigations were performed on a loop thermosyphon, consisting of a condensation section and an evaporation section. The evaporator chamber used in this study has an inside diameter of 25 mmand a height of 25 mm. Three evaporators, without wick structure and with 1 mmand 4 mmthickness wick structures were examined in the test. The experiments were conducted under the condition of 20 C, 30 C, 40 C and 50 C cooling water, for heating powers from 20 to 250 W, working fluid fill ratios of 5%, 10%, 20%, 30%, 40% and 50%. The experiments used methanol and water as the working fluid. When the system reached the steady state, the temperature was recorded in order to evaluate the performance of the thermosyphon. Effect of cooling water temperatures, fluid fill ratio and evaporator type were studied. Finally, the results show that the wick structure can enhance the heat transfer effects directly. The working fluid water can support a large heating range.[[notice]]補正完畢[[incitationindex]]EI[[booktype]]紙