This dissertation is a collection of essays on intellectual property rights and optimal product selection when innovation occurs sequentially. One of the highlights of this dissertation has been to show the possibility of full rent extraction by the patent holder when uncertainty in litigation is taken into consideration. The result of the theoretical model has practical policy implication regarding the design of an optimal patent system. The other highlight of this dissertation is to show the coexistence of maximal and minimal product differentiation in a sequentially growing market. This result sheds light on the simulation of a multi-dimensional product space. Brief Summaries of Chapters: Chapter 1 presents a survey of the historical, legal, and economic aspects of patents. The emphasis in this survey is to recognize the crucial elements in the current patent law practice and to initiate research projects thereof. Chapter 2 considers a model of sequential innovation in which patent infringement occurs and the outcome of litigation is uncertain. By recognizing the "diminishing returns to litigation" exhibited in the winning probability distribution function for the plaintiff, it is shown that a basic researcher holding a patent is able to extract all the profit facilitated by the basic innovation. More intriguingly, under rather general circumstances, broader patent breadth may diminish the patent holder's incentive to innovate. Chapter 3 extends the previous model to include a rule on the reasonable royalty to determine the damage award. In addition to the full rent extraction results, the extended model further reveals that the second innovator has incentive to "invent around" with close imitation or "invent enough" with a much improved product. Comparative statics with respect to parameters of litigation cost and granted patent breadth are performed. Among other things, it is demonstrated that an increase in patent breadth, and an increase of litigation costs may neutralize each other. Chapter 4 analyzes a model of two-dimensional product differentiation in which sequential entry occurs and the potential entrant outperforms the incumbent in innovating a new dimension. For a three-stage entry-variety-price duopoly, a unique subgame-perfect equilibrium is obtained and fully characterized. Most importantly, the entrant will completely utilize its capacity to innovate and achieve the principle of maximum differentiation with respect to the innovated variety. However, it is shown that with a sequentially growing product space, firms will not choose extreme opposite positions in all dimensions in order to soften price competition; the principle of minimum differentiation persists with respect to the traditional variety. / Ph. D.

Retention of engineering students to graduation and career is important business for both United States (U.S.) industries and engineering education institutions alike. Industries need competent engineers dedicated to working in the field of engineering beyond graduation in order to achieve business success and national economic growth, while engineering education institutions need retention to graduation to achieve their own business goals. This dissertation took a three-pronged approach to identifying relationships between depth and specificity of engineering and response factors related to graduation and career retention of engineers. Occupational alignment, graduate school decisions, and engineering identity were evaluated for relationships with specificity or depth of discipline within engineering degrees to evaluate if increasing the depth or specificity increased the response factors. Using historical data analysis, occupational alignment and graduate school decisions were both found to be influenced by specificity of discipline. Traditional engineering disciplines were found to report the most occupational alignment after graduation, while specific engineering disciplines were more likely to attend graduate school after graduation. Additionally, for all students reporting graduate school attendance, all specificities were most likely to align their graduate degree discipline to their undergraduate degree discipline. A national survey of undergraduate engineering students revealed that engineering identity is related to depth of discipline. Students enrolled in more specific engineering curriculum, in the form of a discipline-specific major with a concentration, reported higher engineering identity. However, the discipline-specific depth of discipline followed closely behind, indicating the impact of depth of discipline is small. The largest difference in scores between the two depths of discipline was found in students' reports of a construct termed "interest". Ultimately, this dissertation found statistically significant relationships between depth and specificity of discipline and occupational alignment, graduate school decisions, and engineering identity. Though these findings are statistically significant, they were incremental, meaning depth and specificity of discipline should not be considered the main factor of influence.

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The first chapter of this dissertation examines the returns to frequent acquirers from emerging markets and analyzes the cross-country variations in cumulative abnormal returns. The sample consists of 5,147 transactions carried out by firms from 17 common and civil-law countries during the period of January 1985 to June 2008. I find that the cumulative abnormal returns decline over the deal order and it is more pronounced in civil-law countries than in common-law countries. There is also evidence that the premiums paid by acquirers from civillaw countries with a first successful acquisition are higher than those from common-law countries. These findings are consistent with agency problems and the hubris hypothesis, first introduced by Roll (1986). The second chapter examines the information links across futures markets in different nations, using Vector Autoregressive (VAR)-Dynamic Conditional Correlation (DCC) model. The data comprise a large set of commodity and financial futures traded in U.S., U.K., China, Japan, Canada, and Brazil during the period from August 1998 to December 2008. The primary finding is that market interactions are relatively high for commodities for which information production generally is more diverse (metal commodities), while moderate for commodities for which information is more concentrated (agricultural commodities). Furthermore, the strength and persistence of interactions among futures markets decline after excluding the most informative markets. These findings indirectly support the breadth of information being a relevant factor in the extent of information linkage. The results also indicate that the dynamic correlation in futures markets is high in most commodity and financial futures if there is a significant bi-directional return and volatility spillover. Additionally, I estimate a market’s contribution to the price discovery process. In general, the market that has a stronger price impact and a stronger volatility spillover tends to be the market that has greater contribution or leadership in price discovery.

Submitted by Jean Medeiros (jeanletras@uepb.edu.br) on 2016-02-29T13:53:28Z No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) PDF - Natalice dos Santos Sales.pdf: 3971336 bytes, checksum: 5c5a0633dc255180a572d2b151d73426 (MD5) / Approved for entry into archive by Secta BC (secta.csu.bc@uepb.edu.br) on 2016-06-13T20:31:10Z (GMT) No. of bitstreams: 2 PDF - Natalice dos Santos Sales.pdf: 3971336 bytes, checksum: 5c5a0633dc255180a572d2b151d73426 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2016-06-13T20:31:10Z (GMT). No. of bitstreams: 2 PDF - Natalice dos Santos Sales.pdf: 3971336 bytes, checksum: 5c5a0633dc255180a572d2b151d73426 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2015-02-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Hypersaline estuarine systems the fish species move between areas of greater supply of resources and according to salinity gradient, because the physiological tolerance is a common adaptation to many species of estuarine fish. Moreover, those species can display other behavioral adaptations, such as food flexibility. Thus, this study analized structure and composition of the ichthyofauna in accordance with the salinity gradients as well as ecology and trophic organization. Samples were collected in rainy and dry season, from January to Decembre 2012, in 12 points distributed into three areas defined according to the salinity gradient (Inferior, Intermediate and Upper). The fishes were captured using a beach seine. The low rainfall, high evaporation rate and the small input of freshwater in Tubarão River estuary favored a salinity between 30 and 45. The structure and composition of ichthyofauna showed spatial and temporal differences between the Tubarão River estuary areas, with salinity and substrate influencing the distribution of species. Atherinella brasiliensis, Lile piquitinga, Eucinostomus argenteus, Ulaema lefroyi, Lutjanus analis and Sphoeroides greeleyi are the most abundant distributed in all the estuarine areas. Among the 104 species caught at the estuary of Tubarão River, 18 were selected according to their abundance, for analysis of trophic ecology. However, only the spacial variation showed significant changes in fish diet. In general, the diet of the species was based mainly on Macroalgae, Polychaeta, Decapoda, Mollusca and Zooplankton. Among these items the representatives of Zooplankton are the main prey in the diet of small juveniles. Because of this preference for certain food items species were grouped into six different trophic guilds: Zooplanktivore, Omnivore, Herbivore-Macroalgae, Zoobenthivore- Hyperbenthos, Zoobenthivore-Epifauna and Zoobenthivore-Infauna. The largest overlap values occured in the Upper zone, due to a higher salinity restricting the establishment of various prey. The results presented in this study showed the direct relationship of the structure and composition of ichthyofauna and the trophic ecology with habitat heterogeneity and the variation in salinity. Thus, the data obtained in the study allows our understanding of the dynamics of community structure that hypersaline system and favors the development of approaches to conservation and sustainable use of biological diversity. / Nos sistemas estuarinos hipersalinos as espécies de peixes se movimentam entre os locais de maior oferta de recursos e entre os diferentes gradientes de salinidade, de acordo com a tolerância fisiológica que é uma adaptação comum para espécies de peixes estuarinos. Além disso, estas espécies podem exibir outras adaptações comportamentais, como a flexibilidade alimentar. Assim, o estudo analisou a estrutura e composição da ictiofauna de acordo com o gradiente de salinidade, bem como a ecologia e a organização trófica. As amostragens foram realizadas durante a chuva e a seca de 2012 em 12 pontos distribuídos em três zonas definidas de acordo com o gradiente de salinidade (Inferior, Intermediária e Superior). Os peixes foram capturados com a utilização de uma rede beach seine através de arrasto de praia. O baixo índice pluviométrico, a elevada taxa de evaporação e a pequena entrada de água doce presentes no estuário do Rio Tubarão favoreceram uma salinidade entre 30 e 45. A estrutura e composição da ictiofauna apresentaram diferenças espacial e temporal entre as zonas do estuário do rio Tubarão, com a salinidade e o substrato influenciando na distribuição das espécies Atherinella brasiliensis, Lile piquitinga, Eucinostomus argenteus, Ulaema lefroyi, Lutjanus analis and Sphoeroides greeleyi Dentre as 104 espécies capturadas no estuário do Rio Tubarão 18 foram selecionadas, de acordo com sua abundância, para análise da ecologia trófica. No geral a dieta das espécies foi baseada, principalmente, em Macroalgas, Polychaeta, Decapoda, Mollusca e Zooplâncton. Dentre esses itens os representantes do Zooplâncton são as presas principais na dieta dos pequenos juvenis. Devido a essa preferência por determinados itens alimentares as espécies foram agrupadas em seis guildas tróficas, distintas: Zooplanctívoro, Onívoro. HerbívoroMacroalga, Zoobentívoro-Hiperbentos, Zoobentívoro-Epifauna e Zoobentívoro-Infauna. Os maiores valores de sobreposição foram registrados na zona Superior, possivelmente pela elevada salinidade que restringe o estabelecimento de diversas presas. Em geral os resultados apresentados nesse estudo mostram a relação direta da estrutura e composição da ictiofauna e a ecologia trófica das espécies com a heterogeneidade do habitat e a variação de salinidade que possibilita proteção aos peixes juvenis e maior abundância de recursos tróficos. Assim, os dados obtidos no estudo possibilita a compreensão da dinâmica da estrutura da comunidade desse sistema hipersalino, bem como favorece o desenvolvimento de abordagens para a conservação e uso sustentável da diversidade biológica.

A large amount of on-line information resides on the invisible web - web pages generated dynamically from databases and other data sources hidden from current crawlers which retrieve content only from the publicly indexable Web. Specially, they ignore the tremendous amount of high quality content "hidden" behind search forms, and pages that require authorization or prior registration in large searchable electronic databases. To extracting data from the hidden web, it is necessary to find the search forms and fill them with appropriate information to retrieve maximum relevant information. To fulfill the complex challenges that arise when attempting to search hidden web i.e. lots of analysis of search forms as well as retrieved information also, it becomes eminent to design and implement a distributed web crawler that runs on a network of workstations to extract data from hidden web. We describe the software architecture of the distributed and scalable system and also present a number of novel techniques that went into its design and implementation to extract maximum relevant data from hidden web for achieving high performance.

Optimal Foraging Theory (OFT) has its origin in processualistic ideas in 1960s with traces back to the dawn of the archaeological science in the 19th century. The OFT model is based on the construction of an individual’s food item selection understood as an evolutionary construct that maximizes the net energy gained per unit feeding time. The most common variants are diet patch choice, diet breadth/prey choice models and Marginal Value Theorem (MVT). The theory introduced experimental studies combined with mathematically data analyses and computer simulations. The results visualized in the experimental diagrammed curve are possible to compare with the archaeological records. What is “optimal” is an empirical question not possible to know but still useful as a benchmark for measuring culture. The theory is common in USA but still not in Europe. OFT seems to be useful in hunter-gatherer research looking at human decisions, energy flow, depression of resources and extinction. This literature review concludes that the prey-choice/diet-breadth model seems to be useful for hunter-gatherer research on Gotland focusing on possible causes of the hiatus in archaeological records between 5000-4500 BC. / Optimal Foraging Theory (OFT) har sitt ursprung i de processualistiska ideérna under 1960-talet med spår tillbaka till arkeologins början som vetenskap under 1800-talet. OFT modellen baseras på konstruktionen av en individs födoämnesval som förstås som en evolutionär konstruktion som maximerar nettoenergiintaget per tidsenhet som gått åt för försörjningen. De vanligaste varianterna är patch-choice, diet breadth/prey choice modellerna och Marginal Value Theorem (MVT). Experimentella studier genomförs och data bearbetas matematiskt och visar datorsimulerade kurvdiagram möjliga att jämföra med arkeologiska källmaterial. Vad som är ”optimalt” är en empirisk fråga omöjlig att veta men användbar ändå som en slag referens för att mäta kultur. Teorin är vanlig i USA men ännu inte i Europa. OFT förefaller användbar inom forskning av jägare-samlare om man fokuserar på beslutsfattande, energiflöde, depression av resurser och utrotning av arter. Slutsatsen i denna litteraturöversikt är att prey choice/diet breadth modellen tycks vara användbar för gotländsk jägare-samlare-forskning som fokuserar på möjliga orsaker till de arkeologiska fyndens hiatus mellan 5000-4500 BC.

This dissertation presents an evaluation of coprolite specimens from the Lower Pecos canyonlands as records of individual dietary decisions. Prior studies of coprolites from this region have greatly expanded our knowledge of Archaic subsistence patterns, but have not taken full advantage of the record of individual dietary decisions recorded in each coprolite specimen. The menu, or dietary combinations, reflected in individual coprolite specimens are assessed through the identification of several congruent botanical components derived from the same food resource, phytoliths, fiber ultimates, and epidermal sheets. The data is analyzed with hierarchical cluster analysis, an exploratory statistical technique. The resultant menus reflected in these clusters are evaluated with reference to the diet-breadth model developed for the known staple resources of the canyonlands as well as the seasonal subsistence patterns observed in the ethnohistoric record of modern-day Mexico and Texas. This same technique is also applied to the coprolite data available from previous studies in the Lower Pecos canyonlands. Overall, the combined dietary data available for the Lower Pecos canyonlands presents a similar dependence on desertic plant resources throughout the Archaic. Three main menus are apparent in the specimens. The first menu consists of prickly pear (Opuntia sp.) cladodes, or nopales, and was principally, although not exclusively, consumed in the late spring. This menu is primarily consumed when other resources were not readily available and may be considered a dependable but undesirable meal. The second menu consists of pit-baked lechuguilla (Agave lechuguilla) and sotol (Dasylirion sp.) caudices, or hearts, common throughout the cool season. This menu entails high processing costs, but would provide a reliable caloric return. The third menu exhibits a monolithic reliance on prickly pear fruits, or tunas, during the summer. The ease of harvest and consumption is reflected in the seasonal dominance of this resource, which was assuredly a highly desirable meal. The dietary patterns recorded in the coprolite specimens from the Lower Pecos canyonlands demonstrate a seasonally variable diet-breadth that incorporated low-ranked resources during times of seasonal scarcity as well as a monolithic dependence on high-ranked resources when they were available in the local landscape.

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