The ongoing debate on the evaluative role of citation analysis and the theory of citation recognizes that the citation process is complex and that citation counts are affected by certain extra-scientific or external factors. To date, little effort has been made to explore the effects of various external factors; this thesis addresses this lack. In the context of the various perspectives on citations and citation analysis, this study uses journals as the unit of analysis and investigates what, how, and to what extent extra-scientific factors influence the citation impact of journals. An integrated conceptual model of Journal Citation Impact that takes into account current theoretical positions and prior empirical research findings is developed. It addresses the interrelationships between Journal Citation Impact and a range of external factors (Journal Properties, Journal Visibility, Journal Accessibility, Journal Internationality, Journal Selectivity, Journal Promptness, Journal Editorial Prestige, and Perceived Journal Quality). The proposed conceptual model is novel in that it: (1) incorporates nearly all possible external factors that affect Journal Citation Impact; (2) addresses the complex interrelationships between a number of external factors and Journal Citation Impact in one model; (3) regards both Journal Citation Impact and its external factors as theoretical constructs; and (4) identifies the observed variables of the external factors and Journal Citation Impact. However, because of the difficulties in operationalizing all the theoretical constructs, this conceptual model is simplified to an operational model for empirical testing. The operational model includes the construct Journal Citation Impact and four of its external factors, Journal Properties, Journal Accessibility, Journal Internationality, and Perceived Journal Quality. Structural Equation Modeling (SEM) with Partial Least Squares (PLS) is used to test the operational model with empirical data from 41 research journals in clinical neurology. Data are collected from bibliographic database searching, web searching, printed journals, and from a web-based survey that was conducted to obtain information on perceptions of journal quality. Empirical results of the operational model show that Journal Accessibility, Journal Internationality, and Perceived Journal Quality have large, medium, and small effects respectively on Journal Citation Impact, thus indicating that certain extra-scientific factors can influence Journal Citation Impact significantly. The findings suggest that great care should be taken in interpreting and evaluating the results obtained from citation analysis. In terms of Journal Citation Impact, this research also suggests that various journal citation indicators should be ii used to reflect different aspects of citation impact. By exploring the phenomenological domain in the citing process, this exploratory study not only provides a better understanding of citation analysis, it also contributes to the development of the theory of citation. From the methodological perspective, introducing SEM with PLS to Informetrics and Scientometrics also contributes to the knowledge base of these fields. Pragmatically, the research findings will enhance the judgment of researchers and practitioners such as editors, publishers, librarians and other information specialists in assessing journal performance. Finally, the worldwide survey findings on peer assessment of journal outlets in clinical neurology will be useful for researchers, academics or clinicians in this field.

The ongoing debate on the evaluative role of citation analysis and the theory of citation recognizes that the citation process is complex and that citation counts are affected by certain extra-scientific or external factors. To date, little effort has been made to explore the effects of various external factors; this thesis addresses this lack. In the context of the various perspectives on citations and citation analysis, this study uses journals as the unit of analysis and investigates what, how, and to what extent extra-scientific factors influence the citation impact of journals. An integrated conceptual model of Journal Citation Impact that takes into account current theoretical positions and prior empirical research findings is developed. It addresses the interrelationships between Journal Citation Impact and a range of external factors (Journal Properties, Journal Visibility, Journal Accessibility, Journal Internationality, Journal Selectivity, Journal Promptness, Journal Editorial Prestige, and Perceived Journal Quality). The proposed conceptual model is novel in that it: (1) incorporates nearly all possible external factors that affect Journal Citation Impact; (2) addresses the complex interrelationships between a number of external factors and Journal Citation Impact in one model; (3) regards both Journal Citation Impact and its external factors as theoretical constructs; and (4) identifies the observed variables of the external factors and Journal Citation Impact. However, because of the difficulties in operationalizing all the theoretical constructs, this conceptual model is simplified to an operational model for empirical testing. The operational model includes the construct Journal Citation Impact and four of its external factors, Journal Properties, Journal Accessibility, Journal Internationality, and Perceived Journal Quality. Structural Equation Modeling (SEM) with Partial Least Squares (PLS) is used to test the operational model with empirical data from 41 research journals in clinical neurology. Data are collected from bibliographic database searching, web searching, printed journals, and from a web-based survey that was conducted to obtain information on perceptions of journal quality. Empirical results of the operational model show that Journal Accessibility, Journal Internationality, and Perceived Journal Quality have large, medium, and small effects respectively on Journal Citation Impact, thus indicating that certain extra-scientific factors can influence Journal Citation Impact significantly. The findings suggest that great care should be taken in interpreting and evaluating the results obtained from citation analysis. In terms of Journal Citation Impact, this research also suggests that various journal citation indicators should be ii used to reflect different aspects of citation impact. By exploring the phenomenological domain in the citing process, this exploratory study not only provides a better understanding of citation analysis, it also contributes to the development of the theory of citation. From the methodological perspective, introducing SEM with PLS to Informetrics and Scientometrics also contributes to the knowledge base of these fields. Pragmatically, the research findings will enhance the judgment of researchers and practitioners such as editors, publishers, librarians and other information specialists in assessing journal performance. Finally, the worldwide survey findings on peer assessment of journal outlets in clinical neurology will be useful for researchers, academics or clinicians in this field.

No description available.

Multiple Effect Evaporators (MEE) are used in kraft pulp mills to concentrate black liquor. In order to verify if the MEE is operating at an optimum condition, thermal performance of evaporators is calculated. Due to the interconnection of many variables involved, this can be a challenging task. Thus, this work involved the study of operating data from two Canadian pulp mills using Multivariate Data Analysis (MVDA) techniques: Principal Component Analysis (PCA) and Partial Least Squares Analysis (PLS). Moreover, the evaporation system was modelled using a dynamic simulation software called CADSIM. MVDA determined that the thermal performance of the evaporators was positively correlated with the weak black liquor flow rate and negatively correlated with the steam pressure (to the first effect). The CADSIM model confirmed these findings. Therefore, these two techniques show to be useful tools in identifying operating variables that may be adjusted to improve thermal performance of evaporators.

Multiple Effect Evaporators (MEE) are used in kraft pulp mills to concentrate black liquor. In order to verify if the MEE is operating at an optimum condition, thermal performance of evaporators is calculated. Due to the interconnection of many variables involved, this can be a challenging task. Thus, this work involved the study of operating data from two Canadian pulp mills using Multivariate Data Analysis (MVDA) techniques: Principal Component Analysis (PCA) and Partial Least Squares Analysis (PLS). Moreover, the evaporation system was modelled using a dynamic simulation software called CADSIM. MVDA determined that the thermal performance of the evaporators was positively correlated with the weak black liquor flow rate and negatively correlated with the steam pressure (to the first effect). The CADSIM model confirmed these findings. Therefore, these two techniques show to be useful tools in identifying operating variables that may be adjusted to improve thermal performance of evaporators.

No description available.

No description available.

Thesis (Ph. D.)--University of Missouri-Columbia, 1998. / Typescript. Vita. Includes bibliographical references (leaves 244-246). Also available on the Internet.

Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (leaves 216-234).

Includes bibliographical references (p. 193-208).