TESTS ON SEASONAL UNIT ROOTS IN TAIWAN'S VEGETABLE PRICES

Taiwan's retail and farm prices were examined for unit roots at various seasonal frequencies. The results show that no unit roots exist at any seasonal frequency. Additionally, a unit root exists at the zero frequency in marketing margins, reflecting that retail and farm prices are not co-integrated at the long-run frequency.Crop Production/Industries, Demand and Price Analysis,

A REGIONAL ANALYSIS OF VEGETABLE PRODUCTION WITH CHANGING DEMAND FOR ROW CROPS USING QUADRATIC PROGRAMMING

The purpose of the study was to ascertain the competitive and complementary potential of fresh vegetable production relative to traditional row crop production using a regional partial equilibrium model. It seems clear from the analysis that vegetable crops are not destined in the near future to replace row crops in terms of land utilization. Nevertheless, vegetable crops appear to compete with and complement row crops well as evidenced by substantial increases in production as market share was assumed to increase. However, fresh vegetables cannot be considered as residual enterprises to which producers move when the demand for row crops declines. Even with a simulated 20 percent decrease in the demand for row crops, the acreage of fresh vegetables did not increase.Production Economics,

The interactional achievement of familyhood in Vietnamese-Taiwanese international families

Phd ThesisWhile so many studies relating to Vietnamese female spouses in Taiwan have tapped into crucial issues facilitating understanding of this particular social group, none of them deals with face-to-face interaction between Vietnamese female spouses and their Taiwanese family members. This thesis thus tries to bridge the research gap by studying real-life face-to-face interaction in such transnational families with special attention to identifying the interactional relevance and consequentiality of membership categories invoked by the family members and how Taiwanese and Mandarin are used as interactional resources in familial discourse. This study engaged 3 Vietnamese wives in Taiwan along with 14 Taiwanese family members whose mealtime talks were audio-/video‐recorded. Conversation analysis (CA) and membership categorisation analysis (MCA) were adopted to analyse the 7 hours of data collected. It was found (from the corpus of recordings) that a Vietnamese spouse’s deployment of the membership categories ‘Taiwanese’ and ‘Vietnamese’ relates to her use of first-person plural pronouns to form the (literally translated) ‘we + country’ compound. The compound is found to be a distinctive identity-related device used by the Vietnamese participants to engage in self-categorisation. Moreover, it is also an epistemics-related device used by the Vietanamese spouses to ascribe authority or expertise to themselves or their Taiwanese family members in the enactment of 'Vietnamese' or 'Taiwanese'. On the other hand, it was found that the Vietnamese participants orient to Taiwanese and Mandarin as salient resources in admonishment sequences. Specifically, the two languages serve as contextualisation cues and framing devices in 3 different types of admonishment sequences. It is identified that familyhood can be achieved in an admonishment context, in which language varieties are used by adult family members to facilitate their alignment with each other in educating the youngest generation. The research findings suggest that the Vietnamese female spouses can fabricate interactional resources into devices to actively engage in familial communicative events and fulfil their responsibilities as a family member and as a mother. From the discursive construction of national and household identity categories, the Vietnamese spouses have demonstrated how they manage identity work and position themselves in the family; on the other hand, the way that participants negotiate national identities in family discourse have made salient the transnationality pertaining to the families. The study therefore contributes to enriching the understanding of Vietnamese female spouses in Taiwan from a conversation and membership categorisation analytic perspective, and the research findings serve as a reference point for research on cross-border marriage, cross-border couples and interactional patterns in transnational families

Using futures and option contracts to manage price and quantity risk: A case of corn farmers in central Iowa

The overall objective of this study is to examine the optimal responses of a risk-averse corn producer to price and quantity risks within a framework where both futures and option contracts are available as risk management tools. The corn farmer is selected as a representative decision maker because corn is the most important crop in Iowa;Numerical techniques are used to solve the expected utility maximization problem for the corn producer. In forming his subjective probability distributions about random variables, the farmer is assumed to predicate output which will be sell to cash market at a later date and use futures and put options to hedge against the risk associated with his cash position. To decide the optimal hedging strategy, the farmer also makes predictions on the cash, futures, and option prices prevailing at the end of period. Optimal positions are obtained for three scenarios: (1) the producer considers only futures, (2) the producer considers only put options, (3) the producer considers both futures and put options as risk management tools. Comparative static results regarding the impact of model parameters such as frame size, risk attitudes, price levels, and price variances on the optimal solution are then examined. The access values of futures, options, and futures-and-options added to the producer are computed based on the concept of certainty equivalent;The optimal solution indicates that put options are used not only as for hedging purpose but also as speculative tools. From hedging standpoint, however, the option market offers no additional benefit to the expected utility maximizing producer if futures contracts are already in use;The access values added to the corn producer show that the futures contracts have a greater value to the producer than does the option contracts. The primary factors determining the access value of options are farm size, the variability of prices, and the level of risk aversion

APPLICATION OF THIN FILM ANALYSIS TECHNIQUES AND CONTROLLED REACTION ENVIRONMENTS TO MODEL AND ENHANCE BIOMASS UTILIZATION BY CELLULOLYTIC BACTERIA

Cellulose from energy crops or agriculture residues can be utilized as a sustainable energy resource to produce biofuels such as ethanol. The process of converting cellulose into solvents and biofuels requires the saccharification of cellulose into soluble, fermentable sugars. However, challenges to cellulosic biofuel production include increasing the activity of cellulose-degrading enzymes (cellulases) and increasing solvent (ethanol) yield while minimizing the co-production of organic acids. This work applies novel surface analysis techniques and fermentation reactor perturbations to quantify, manipulate, and model enzymatic and metabolic processes critical to the efficient production of cellulosic biofuels. Surface analysis techniques utilizing cellulose thin film as the model substrate are developed to quantify the kinetics of cellulose degradation by cellulase as well as the interactions with cellulase at the interfacial level. Quartz Crystal Microbalance with Dissipation (QCM-D) is utilized to monitor the change in mass of model cellulose thin films cast. The time-dependent frequency response of the QCM simultaneously measures both enzyme adsorption and hydrolysis of the cellulose thin film by fungal cellulases, in which a significant reduction in the extent of hydrolysis can be observed with increasing cellobiose concentrations. A mechanistic enzyme reaction scheme is successfully applied to the QCM frequency response for the first time, describing adsorption/desorption and hydrolysis events of the enzyme, inhibitor, and enzyme/inhibitor complexes. The effect of fungal cellulase concentration on hydrolysis is tested using the QCM frequency response of cellulose thin films. Atomic Force Microscopy (AFM) is also applied for the first time to the whole cell cellulases of the bacterium C. thermocellum, where the effect of temperature on hydrolysis activity is quantified. Fermentation of soluble sugars to desirable products requires the optimization of product yield and selectivity of the cellulolytic bacterium, Clostridium thermocellum. Metabolic tools to map the phenotype toward desirable solvent production are developed through environmental perturbation. A significant change in product selectivity toward ethanol production is achieved with exogenous hydrogen and the addition of hydrogenase inhibitors (e.g. methyl viologen). These results demonstrate compensatory product formation in which the shift in metabolic activity can be achieved through environmental perturbation without permanent change in the organism’s genome

DYNAMIC LINKAGES BETWEEN PRICES AND IMPORTS FOR JAPANESE FROZEN TUNA

VAR models have been used to describe the dynamic relationships among market price, Japanese harvest, import-from-Taiwan, and import-from-Korea for frozen Big-Eye tuna and Yellow-Fin tuna markets in Japan. It is found that tuna imports from South Korea exert more significant effects on Japan market prices than import-from-Taiwan.Demand and Price Analysis, International Relations/Trade,