206473788
Booth's law of word frequency
Booth’s (1967) law is widely used to model the incidence of low frequency words in English text. Fedorowicz (198 1, 1982a, 1982b) used equation (3) below to study automated bibliographic systems. Pao (1978) used equation (4) to derive a transition point in automatic text analysis. The present communication confirms this usage, corrects a deficiency in the original derivation, and makes the results more general. Booth’s results are based on Zipf’s (1949) well-known relationship between the probability of occurrence, p(r), and the corresponding rank, r, of a word where
46601989
Analysis of Lotka's law: The Simon-Yule approach
Abstract A major difficulty in using the well-known Lotka's law in information science is in the estimation of parameters. In this paper, we argue that the difficulty arises from the misuse of goodness-of-fit tests. As an alternative, we adopt Simon's five-step modeling process for the study of Lotka's law. Three significant contributions can be identified. First, an index approach is used to identify a general formulation of Lotka's law. Second, a time series approach is used to identify two influential variables associated with the empirical data. Third, the constructive mechanism proposed by Simon is used to derive a distribution resembling the general formulation of Lotka's law. Further research on refining the constructive mechanism is suggested.
32843088
Analysis of Zipf's law: An index approach
Abstract A rigorous analysis of Zipf's law is made using an index for the sequence of observed values of the variables in a Zipf-type relationship. Three important properties relating rank, count, and frequency are identified. Using this approach, the shape of Zipf-type curves can be described in terms of three distinct regions and two parameters of the Mandelbrot-Zipf law. This result has considerable practical significance, since it provides rigorous foundations for the application of Zipf's law.
14708618
Enhancing UML Conceptual Modeling through the Use of Virtual Reality
UML is one of the major conceptual modeling tools in Object-Oriented software engineering. However, recently more and more concerns arise from the modeling quality of UML. Among them, limitation of the two-dimensional presentation of its notations is reported to be significant. By bringing in the concepts of Steoropsis (3-D appearance), animation, interaction and immersion, Virtual Reality may improve the UML modeling quality. Specifically, in this paper we analyze the modeling quality of UML by using recent published literature in conceptual modeling. We then recommend the use of Virtual Reality to enhance the modeling quality of UML. Some examples of how Virtual Reality can be used to improve UML modeling quality are given. Finally, we propose a research framework for enhancing the quality of UML conceptual modeling through the use of Virtual Reality.
16469592
IT businesses and franchising: a research proposal
Franchising has been popular as a growth strategy for small businesses; it is even more so in today's global and information-based economy. In early 2001, Entrepreneur magazine-well known for its Franchise 500 listing-added a tech businesses category to its franchise zone with three subcategories: Internet businesses, tech training, and miscellaneous tech businesses. This study applies Herbert Simon's model for business firm growth as a theory-grounded solution to help managers understand the growth dynamics of IT-based franchising businesses. We present a research proposal with a pilot study of the growth of 27 IT-based franchise businesses, and explain how to relate the parameters of Simon's model to strategic variables that can give managers a valuable strategic tool to understand the context of their industrial competition in IT-based franchising.
7851375
The Simon-Yule Approach to Bibliometric Modeling
Abstract Using an index approach to take into account the scattering pattern of the observed values, Chen and Leimkuhler showed that the three well-known bibliometric distributions (i.e., Lotka's law of scientific productivity, Bradford's law of bibliographic scattering, and Zipf's law of word frequency) are equivalent. Furthermore, Chen showed that Lotka's law can be derived from a generating mechanism (the Simon-Yule Model) proposed by Herbert A. Simon. In this paper, we use a simulation algorithm based on the Simon-Yule model to conduct computational experimentation on these three laws. The results indicate that the probability of a new entry (α), be it constant or decreasing, determines the characteristics of all three distributions.
17642380
Evolutionary Modeling of Ordinary Differential Equations for Dynamic Systems
This paper presents a new idea of modeling one-dimensional dynamic systems by higher-order ordinary differential equation (HODE) models in stead of by the ARMA models used in the traditional time series analysis. Accordingly, based on the idea of hybrid evolutionary modeling, we modify the HEMA algorithm in (Cao et al., 1998a; Cao et al., 1998b) to approach the modeling problem of HODEs for dynamic systems. Two applications of time series are used to demonstrate its effectiveness and advantages.
3447304
Measuring the Dependability of Web Services for Use in e-Science Experiments
This paper introduces a dependability assessment tool (WSsDAT) for Web Services monitoring and testing. It allows users to evaluate dependability of Web Services from the point of view of their clients by collecting metadata representing a number of dependability metrics. This Java-based tool can be deployed in diverse geographical locations to monitor and test the behavior of a selected set of Web Services within preset time intervals. The graphical user interface of the tool provides real-time statistical data describing dependability of the Web Services under monitoring. The tool makes it possible for the users to identify typical patterns of dependability-specific behavior depending on the time of the day, days of the week or the client locations. In addition, WSsDAT can collect and analyze service dependability measurements during long periods of time, as well as obtaining dependability-related information about current service behavior. The paper reports on a successful series of experiments using this tool for investigating the dependability of two BLAST Web Services which are widely used in the bioinformatics domain. The paper shows how the tool can be employed by e-scientists in making informed choices of the distributed services being used in an in silico experiment and thereby improving their overall dependability.
10261174
Microarchitecture-aware floorplanning using a statistical design of experiments approach
Since across-chip interconnect delays can exceed a clock cycle in nanometer technologies, it has become essential in high performance designs to add flip-flops on wires with multi-cycle delays. Although such a wire pipelining strategy allows higher operating frequencies, it can reduce the delivered performance of a microarchitecture, since the extra flip-flops inserted may increase the operation latencies and stall cycles. Moreover, the addition of latencies on some wires can have a large impact on the overall performance while other wires are relatively insensitive to additional latencies. This varying sensitivity suggests the need for a throughput-aware strategy for pipelining the interconnects that interacts closely with the physical design step, which determines the lengths of these multicycle wires. We use a statistical design of experiments strategy based on a multifactorial design, which intelligently uses a limited number of simulations to rank the importance of the wires. When applied at the floorplanning level, our results show improvements both in the overall system performance and in the total wire length when compared with an existing technique.
9049589
A service-oriented modeling and simulation framework for rapid development of distributed applications
Abstract The paper presents a service-oriented distributed modeling and simulation framework that supports the development and evaluation of large scale distributed systems such as network-centric and system-of-systems applications. The distinct features of the framework include a modeling and specification language, dynamic model checking for completeness and consistency, automated code generation from the specification, simulation of different architectures with a template-based platform builder, service-oriented multi-agent simulation for easy re-configuration and re-composition, formal policy specification and enforcement for dynamic verification, and dynamic analyses for evaluation and monitoring. The framework and most of the tools reported in this paper have been implemented and applied in several industrial projects. This paper presents the design principles, user interfaces, its runtime infrastructure, and the experiment results on its performance.
2396817
Automatic Pattern-Taxonomy Extraction for Web Mining
In this paper, we propose a model for discovering frequent sequential patterns, phrases, which can be used as profile descriptors of documents. It is indubitable that we can obtain numerous phrases using data mining algorithms. However, it is difficult to use these phrases effectively for answering what users want. Therefore, we present a pattern taxonomy extraction model which performs the task of extracting descriptive frequent sequential patterns by pruning the meaningless ones. The model then is extended and tested by applying it to the information filtering system. The results of the experiment show that pattern-based methods outperform the keyword-based methods. The results also indicate that removal of meaningless patterns not only reduces the cost of computation but also improves the effectiveness of the system.