In emergent high technology industries, entrepreneurs and their new ventures play a critical role in enhancing economic growth. In these industries, we can easily see some new ventures grow more rapidly to outperform their competitors. However, looking beyond the surface, new ventures’ growth path is idiosyncratic. More specifically, when growing, new ventures pursue different paths in terms of 1) which technologies they develop, 2) which products they make, and 3) what markets they enter. The question that has struck me is why high-tech new ventures differ on these key strategic choices. Building on literature on entrepreneurship, strategy, industry evolution, and network, this dissertation tries to answer this important question by focusing on intra-firm factors, more specifically, the individual and structural attributes of new ventures. Types of founder experience and new ventures’ knowledge structure are examined in depth. My three studies, each presented as a separate essay herein, investigate how individual (i.e. founder experience) and structural attributes (i.e. knowledge structure) affect key strategic choices regarding i) product market scope (Wernerfelt and Montgomery, 1988), ii) technological search scope (Katila and Ahuja, 2002), and iii) the types of new products (Sanchez and Mahoney, 1996; Henderson and Clark, 1990), respectively. In each, I discuss the relevant theories, methodology, data sources, results and implications. By investigating intra-firm factors that trigger different entrepreneurial strategies, my dissertation responds to an important call – micro-foundation of strategy formation – thus filling a key gap in the entrepreneurship literature. / Business Administration/Strategic Management

With the exponential growth of the Web and the inherent polysemy and synonymy problems of the natural languages, search engines are facing many challenges such as information overload, mismatch of search results, missing relevant documents, poorly organized search results, and mismatch of human mental model of clustering engines. To address these issues, much effort including employing different information retrieval (IR) models, information categorization/clustering, personalization, semantic Web, ontology-based IR, and so on, has been devoted to improve the relevance of search results. The major focus of this study is to dynamically re-organize Web search results under a socially constructed hierarchical knowledge structure, to facilitate information seekers to access and manipulate the retrieved search results, and consequently to improve the relevance of search results. / To achieve the above research goal, a special search-browser is developed, and its retrieval effectiveness is evaluated. The hierarchical structure of the Open Directory Project (ODP) is employed as the socially constructed knowledge structure which is represented by the Tree component of Java. Yahoo! Search Web Services API is utilized to obtain search results directly from Yahoo! search engine databases. The Lucene text search engine calculates similarities between each returned search result and the semantic characteristics of each category in the ODP; and thus to assign the search results to the corresponding ODP categories by Majority Voting algorithm. When an interesting category is selected by a user, only search results categorized under the category are presented to the user, and the quality of the search results is consequently improved. / Experiments demonstrate that the proposed approach of this research can improve the precision of Yahoo! search results at the 11 standard recall levels from an average 41.7 per cent to 65.2 per cent; the improvement is as high as 23.5 per cent. This conclusion is verified by comparing the improvements of the P@5 and P@10 of Yahoo! search results and the categorized search results of the special search-browser. The improvement of P@5 and P@10 are 38.3 per cent (85 per cent - 46.7 per cent) and 28 per cent (70 per cent - 42 per cent) respectively. The experiment of this research is well designed and controlled. To minimize the subjectiveness of relevance judgments, in this research five judges (experts) are asked to make their relevance judgments independently, and the final relevance judgment is a combination of the five judges’ judgments. The judges are presented with only search-terms, information needs, and the 50 search results of Yahoo! Search Web Service API. They are asked to make relevance judgments based on the information provided above, there is no categorization information provided. / The first contribution of this research is to use an extracted category-document to represent the semantic characteristics of each of the ODP categories. A category-document is composed of the topic of the category, description of the category, the titles and the brief descriptions of the submitted Web pages under this category. Experimental results demonstrate the category-documents of the ODP can represent the semantic characteristics of the ODP in most cases. Furthermore, for machine learning algorithms, the extracted category-documents can be utilized as training data which otherwise demand much human labor to create to ensure the learning algorithm to be properly trained. The second contribution of this research is the suggestion of the new concepts of relevance judgment convergent degree and relevance judgment divergent degree that are used to measure how well different judges agree with each other when they are asked to judge the relevance of a list of search results. When the relevance judgment convergent degree of a search-term is high, an IR algorithm should obtain a higher precision as well. On the other hand, if the relevance judgment convergent degree is low, or the relevance judgment divergent degree is high, it is arguable to use the data to evaluate the IR algorithm. This intuition is manifested by the experiment of this research. The last contribution of this research is that the developed search-browser is the first IR system (IRS) to utilize the ODP hierarchical structure to categorize and filter search results, to the best of my knowledge.

No description available.

隨著資訊科技的蓬勃發展，經由資訊媒介的傳播，造成了企業或組織內部資訊大量的累積。因此，知識倉儲(knowledge repository)可以說是儲存各類型文件的儲存庫，主要用來管理和組織各類型資訊，例如資料庫、報告、文件、表單，都可以數位化方式儲存在知識倉儲，其功能在於進行組織內部各類型文件知識內容管理，進而協助組織提供網路服務(web service)，包括：提供目錄、索引以協助使用者尋找資訊的檢索服務以及辨識和確認資訊位址的定址服務。因此，當知識不斷地從組織運作之中產生，知識與資訊的量也跟著不斷增加，如何管理這些知識就益顯重要，包括知識的表達、結構、儲存與取用方式等。 在這篇論文中，本研究試圖整理對於知識倉儲的『知識結構』之相關或背景知識，並針對文件彼此之間的相互參照關係以及索引典建立知識地圖(knowledge map)，進一步將領域的相關知識，如術語或關連性等資料儲存成有結構性之知識，利用此領域知識對於文件內容附加上有語意關係之處理，在進行資訊檢索時，從而利用領域知識結構以協助使用者準確地檢索與查詢有用或相關之資訊內容。 本研究運用檔案管理全宗理論及控制層級(control level)，提出因應組織結構改變之檔案系統目錄結構，劃分全宗、系列、案卷、文件等層次，知識倉儲系統藉由文件虛擬位址(DL)以及文件實體位址(URL)之對映，以處理組織結構改變之動態文件管理。本研究進一步針對具有關連的一組文件進行案卷內部分類，利用所分析之案卷類型結構，描述具有單一文件以及具有複合文件概念之文件，包括：會議記錄、法令規章等，並運用都柏林核心集(Dublin Core)描述文件資料建立Metadata結構，然後透過索引典(Thesaurus)詞彙語意關係之處理，提供概念性之語意資訊檢索。

There is almost a universal agreement among scholars in information retrieval (IR) research that knowledge representation needs improvement. As core component of an IR system, improvement of the knowledge representation system has so far involved manipulation of this component based on principles such as vector space, probabilistic approach, inference network, and language modeling, yet the required improvement is still far from fruition. One promising approach that is highly touted to offer a potential solution exists in the cognitive paradigm, where knowledge representation practice should involve, or start from, modeling the human conceptual system. This study based on two related cognitive theories: the theory-based approach to concept representation and the psychological theory of semantic relations, ventured to explore the connection between the human conceptual model and the knowledge representation model (represented by samples of concepts and relations from the unified medical language system, UMLS). Guided by these cognitive theories and based on related and appropriate data-analytic tools, such as nonmetric multidimensional scaling, hierarchical clustering, and content analysis, this study aimed to conduct an exploratory investigation to answer four related questions. Divided into two groups, a total of 89 research participants took part in two sets of cognitive tasks. The first group (49 participants) sorted 60 food names into categories followed by simultaneous description of the derived categories to explain the rationale for category judgment. The second group (40 participants) performed sorting 47 semantic relations (the nonhierarchical associative types) into 5 categories known a priori. Three datasets resulted as a result of the cognitive tasks: food-sorting data, relation-sorting data, and free and unstructured text of category descriptions. Using the data analytic tools mentioned, data analysis was carried out and important results and findings were obtained that offer plausible explanations to the 4 research questions. Major results include the following: (a) through discriminant analysis category members were predicted consistently in 70% of the time; (b) the categorization bases are largely simplified rules, naïve explanations, and feature-based; (c) individuals theoretical explanation remains valid and stays stable across category members; (d) the human conceptual model can be fairly reconstructed in a low-dimensional space where 93% of the variance in the dimensional space is accounted for by the subjects performance; (e) participants consistently classify 29 of the 47 semantic relations; and, (f) individuals perform better in the functional and spatial dimensions of the semantic relations classification task and perform poorly in the conceptual dimension.

Made available in DSpace on 2016-04-28T18:22:11Z (GMT). No. of bitstreams: 1 Erisana Celia Sanches Victoriano.pdf: 3011444 bytes, checksum: 0077e3316d46d2f7b287c64a52b1f91d (MD5) Previous issue date: 2010-10-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The new ICTs have been used in face-to-face and distance courses to support and enrich teaching-learning processes. However, their use demands planning and adequacy so that it corresponds to educational goals. For this reason, many studies have been developed. They usually focus on the use of the tools, or on the roles teachers and students play during the interactions (Gervai, 2007; Costa, 2005; Leal, 2005). However, these investigations do not seem to consider language as central in teaching-learning processes; they do not discuss the importance of pedagogic practice and the knowledge structure that are involved in the interactions. In order to contribute to the filling of these gaps, this research was suggested. Therefore, the general objective of this study is to contribute to the improvement on the use of ICTs, more specifically to the use of synchronous communication tools in educational contexts, by considering language as central in teaching-learning processes. In order to reach this goal, seven synchronous sessions (chats) were collected from a distance course that was offered for teachers of English. In addition, the data were analysed under two theoretical frameworks: the systemic-functional theory and the Bernstenian social theory. The analysis developed during this research favoured detailed comprehension about some kinds of interactions that can take place in online synchronous communication in educational contexts, as it highlighted differences in the pedagogic and discursive practices, and in the knowledge structure during the sessions. The analysis developed with the support of the systemic-functional approach for the description of conversations, exchange structure (Martin, 1992), allowed a detailed study of some discursive practices that can take place during this kind of communication. This analysis, combined with the concepts of regulative and instructional discourse suggested in the Bernsteinian theory (Bernstein, 1990), allowed reflections about pedagogic practices that had been involved in the online synchronous sessions. Finally, the concept of entity (Martin and Rose, 2003) and the concepts of horizontal and vertical discourse (Bernstein, 1990) contributed to the comprehension about the nature of knowledge which had been involved in the interactions. This research indicates that the combination of the systemic-functional theory and the Bernsteinian theory can be powerful for the comprehension of language, pedagogic practices and different nature of knowledge that were brought to the interactions; and, it presents results which can contribute to an adequate use of chats in educational contexts , and to the quality of distance education / As tecnologias de informação e comunicação (TICs) vêm sendo usadas em cursos presenciais e a distância com o objetivo apoiar e enriquecer o ensino-aprendizagem. Porém, seu uso exige planejamento e adequação para que corresponda aos objetivos educacionais. Por esse motivo, muitos estudos vêm sendo conduzidos. Esses estudos geralmente focam o uso das próprias ferramentas, ou o papel de professores e alunos durante as interações (Gervai, 2007; Costa, 2005; Leal, 2005). No entanto, essas investigações não consideram a centralidade da linguagem no ensino-aprendizagem, e não discutem a importância da prática pedagógica e das naturezas do conhecimento envolvidas nas interações. Para contribuir com o preenchimento dessas lacunas, esta pesquisa foi proposta. Dessa forma, o objetivo geral deste trabalho é contribuir para o aprimoramento do uso das TICs, mais especificamente com o uso de ferramentas de comunicação síncrona, em contexto educacional considerando a centralidade lingüística em contextos de ensino-aprendizagem. Para tal, sete sessões síncronas online (bate-papos) foram coletadas de um curso a distância, oferecido para professores de inglês. Além disso, os dados foram analisados sob duas perspectivas teóricas: a teoria sistêmico-funcional e a teoria social Bernsteiniana. Ao apontar diferenças nas práticas discursivas e pedagógicas, e na estrutura do conhecimento durante as sessões, a análise conduzida durante essa pesquisa ajudou a compreender mais detalhadamente o tipo de interação que pode acontecer em comunicações síncronas online em contexto educacional. A análise conduzida com ajuda do conceito sistêmico-funcional de estrutura da troca (Martin, 1992) possibilitou um estudo detalhado de algumas práticas discursivas que podem acontecer neste tipo de comunicação online. Essa análise, combinada com os conceitos de discurso regulador e instrucional propostos na teoria bernsteiniana (Bernstein, 1990) permitiu reflexões sobre as práticas pedagógicas que estiveram envolvidas nas sessões síncronas online. Por fim, o conceito de entidade (Martin e Rose, 2003) e os conceitos de discurso horizontal e discurso vertical (Bernstein, 1990), colaboraram para o entendimento sobre a natureza dos conhecimentos envolvidos nas interações. Esta pesquisa indica que a combinação da teoria sistêmico-funcional com a teoria Bernsteiniana mostra-se ferramenta poderosa para a compreensão da linguagem, da prática pedagógica e das diferentes naturezas de conhecimentos trazidos para contextos educacionais; e, apresenta resultados que podem contribuir com usos adequados de ferramentas síncronas digitais em contexto educacional e, assim, com a melhoria da qualidade da educação a distância.

Made available in DSpace on 2016-04-28T18:22:12Z (GMT). No. of bitstreams: 1 Erisana Celia Sanches Victoriano.pdf: 3011444 bytes, checksum: 0077e3316d46d2f7b287c64a52b1f91d (MD5) Previous issue date: 2010-10-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The new ICTs have been used in face-to-face and distance courses to support and enrich teaching-learning processes. However, their use demands planning and adequacy so that it corresponds to educational goals. For this reason, many studies have been developed. They usually focus on the use of the tools, or on the roles teachers and students play during the interactions (Gervai, 2007; Costa, 2005; Leal, 2005). However, these investigations do not seem to consider language as central in teaching-learning processes; they do not discuss the importance of pedagogic practice and the knowledge structure that are involved in the interactions. In order to contribute to the filling of these gaps, this research was suggested. Therefore, the general objective of this study is to contribute to the improvement on the use of ICTs, more specifically to the use of synchronous communication tools in educational contexts, by considering language as central in teaching-learning processes. In order to reach this goal, seven synchronous sessions (chats) were collected from a distance course that was offered for teachers of English. In addition, the data were analysed under two theoretical frameworks: the systemic-functional theory and the Bernstenian social theory. The analysis developed during this research favoured detailed comprehension about some kinds of interactions that can take place in online synchronous communication in educational contexts, as it highlighted differences in the pedagogic and discursive practices, and in the knowledge structure during the sessions. The analysis developed with the support of the systemic-functional approach for the description of conversations, exchange structure (Martin, 1992), allowed a detailed study of some discursive practices that can take place during this kind of communication. This analysis, combined with the concepts of regulative and instructional discourse suggested in the Bernsteinian theory (Bernstein, 1990), allowed reflections about pedagogic practices that had been involved in the online synchronous sessions. Finally, the concept of entity (Martin and Rose, 2003) and the concepts of horizontal and vertical discourse (Bernstein, 1990) contributed to the comprehension about the nature of knowledge which had been involved in the interactions. This research indicates that the combination of the systemic-functional theory and the Bernsteinian theory can be powerful for the comprehension of language, pedagogic practices and different nature of knowledge that were brought to the interactions; and, it presents results which can contribute to an adequate use of chats in educational contexts , and to the quality of distance education / As tecnologias de informação e comunicação (TICs) vêm sendo usadas em cursos presenciais e a distância com o objetivo apoiar e enriquecer o ensino-aprendizagem. Porém, seu uso exige planejamento e adequação para que corresponda aos objetivos educacionais. Por esse motivo, muitos estudos vêm sendo conduzidos. Esses estudos geralmente focam o uso das próprias ferramentas, ou o papel de professores e alunos durante as interações (Gervai, 2007; Costa, 2005; Leal, 2005). No entanto, essas investigações não consideram a centralidade da linguagem no ensino-aprendizagem, e não discutem a importância da prática pedagógica e das naturezas do conhecimento envolvidas nas interações. Para contribuir com o preenchimento dessas lacunas, esta pesquisa foi proposta. Dessa forma, o objetivo geral deste trabalho é contribuir para o aprimoramento do uso das TICs, mais especificamente com o uso de ferramentas de comunicação síncrona, em contexto educacional considerando a centralidade lingüística em contextos de ensino-aprendizagem. Para tal, sete sessões síncronas online (bate-papos) foram coletadas de um curso a distância, oferecido para professores de inglês. Além disso, os dados foram analisados sob duas perspectivas teóricas: a teoria sistêmico-funcional e a teoria social Bernsteiniana. Ao apontar diferenças nas práticas discursivas e pedagógicas, e na estrutura do conhecimento durante as sessões, a análise conduzida durante essa pesquisa ajudou a compreender mais detalhadamente o tipo de interação que pode acontecer em comunicações síncronas online em contexto educacional. A análise conduzida com ajuda do conceito sistêmico-funcional de estrutura da troca (Martin, 1992) possibilitou um estudo detalhado de algumas práticas discursivas que podem acontecer neste tipo de comunicação online. Essa análise, combinada com os conceitos de discurso regulador e instrucional propostos na teoria bernsteiniana (Bernstein, 1990) permitiu reflexões sobre as práticas pedagógicas que estiveram envolvidas nas sessões síncronas online. Por fim, o conceito de entidade (Martin e Rose, 2003) e os conceitos de discurso horizontal e discurso vertical (Bernstein, 1990), colaboraram para o entendimento sobre a natureza dos conhecimentos envolvidos nas interações. Esta pesquisa indica que a combinação da teoria sistêmico-funcional com a teoria Bernsteiniana mostra-se ferramenta poderosa para a compreensão da linguagem, da prática pedagógica e das diferentes naturezas de conhecimentos trazidos para contextos educacionais; e, apresenta resultados que podem contribuir com usos adequados de ferramentas síncronas digitais em contexto educacional e, assim, com a melhoria da qualidade da educação a distância

No description available.