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Authenticating Query Results In Edge Computing, Hwee Hwa Pang, Kian-Lee Tan Mar 2004

Authenticating Query Results In Edge Computing, Hwee Hwa Pang, Kian-Lee Tan

Research Collection School Of Computing and Information Systems

Edge computing pushes application logic and the underlying data to the edge of the network, with the aim of improving availability and scalability. As the edge servers are not necessarily secure, there must be provisions for validating their outputs. This paper proposes a mechanism that creates a verification object (VO) for checking the integrity of each query result produced by an edge server - that values in the result tuples are not tampered with, and that no spurious tuples are introduced. The primary advantages of our proposed mechanism are that the VO is independent of the database size, and that …

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Tool Support For Two-Tiered Architectural Design For Automotive Control Systems, Kevin Steppe, Greg Bylenok, David Garlan, Bradley Schmerl, Kanat Abirov, Nataliya Shevchenko Jan 2004

Tool Support For Two-Tiered Architectural Design For Automotive Control Systems, Kevin Steppe, Greg Bylenok, David Garlan, Bradley Schmerl, Kanat Abirov, Nataliya Shevchenko

Research Collection School Of Computing and Information Systems

An attractive approach to architecture-based design is to structure the development process into two tiers. The top tier represents the abstract design (or architecture) of a system in terms of abstract components. The bottom tier refines that design by making specific implementation decisions, such as platform, middleware, and component implementations. While attractive in principle, there has been relatively little industrial-based experience to shed light on problems and solutions involved in such an approach. In this paper we describe our experience in developing tools to introduce a two-tiered model-based approach to the design of Ford Motor Company’s automotive control systems, highlighting …

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Singapore Management University Report To Stakeholders 2004 - 2005, Singapore Management University Jan 2004

Singapore Management University Report To Stakeholders 2004 - 2005, Singapore Management University

Report to Stakeholders

As the Singapore Management University moves into the Singapore centre, a whole new interchange between education and city takes hold in this revitalised urban environment. Bridging the scholastic origins of Bras Basah with the promise of the new millennium, SMU is at the centre of a new and dynamic educational hub where foundations are being readapted and the future redefined. Every facet of the SMU experience – academic programmes and research, faculty and staff enterprise, student activity and exploration – embraces the University’s passion for creativity, personal interchange and bold challenge.

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Web Usage Mining: Algorithms And Results, Ee Peng Lim, Yew-Kwong Woon, Wee-Keong Ng Jan 2004

Web Usage Mining: Algorithms And Results, Ee Peng Lim, Yew-Kwong Woon, Wee-Keong Ng

Research Collection School Of Computing and Information Systems

No abstract provided.

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A Secure And Privacy Enhanced Location-Based Service Transaction Protocol In Ubiquitous Computing Environment, Konidala Divyan, Robert H. Deng, Jianying Zhou, Kwanjo Kim Jan 2004

A Secure And Privacy Enhanced Location-Based Service Transaction Protocol In Ubiquitous Computing Environment, Konidala Divyan, Robert H. Deng, Jianying Zhou, Kwanjo Kim

Research Collection School Of Computing and Information Systems

Nowadays mobile phones and PDAs are part and parcel of our lives. By carrying a portable mobile device with us all the time we are already living in partial Pervasive Computing Environment (PCE) that is waiting to be exploited very soon. One of the advantages of pervasive computing is that it strongly supports the deployment of Location-Based Service(s) (LBSs). In PCE, there would be many competitive service providers (SPs) trying to sell different or similar LBSs to users. In order to avail a particular service, it becomes very di#cult for a low-computing and resourcepoor mobile device to handle many such …

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Powerful Change Part 2: Reducing The Power Demands Of Mobile Devices, Rajesh Krishna Balan Jan 2004

Powerful Change Part 2: Reducing The Power Demands Of Mobile Devices, Rajesh Krishna Balan

Research Collection School Of Computing and Information Systems

Consumers expect their mobile devices to be small and light, have a decent battery lifetime, and still be powerful enough to run all their desired applications. The need to satisfy such consumer demands has driven mobile-device manufacturers to make products (such as PDAs and cell phones) that match these needs. However, this inevitably requires tradeoffs. Building smaller, lighter devices requires sacrificing the device's battery capacity because battery technology is still fairly dense and heavy, and contributes most of a mobile device's size and weight. But, mobile devices with the required resources to run useful desktop applications need additional battery power …

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Evaluating The Usability Of A Group Support System Using Co-Discovery, Keng Siau Jan 2004

Evaluating The Usability Of A Group Support System Using Co-Discovery, Keng Siau

Research Collection School Of Computing and Information Systems

Group Support Systems (GSSs) have emerged as a new type of information system to aid group decision-making. With the proliferation of such systems in organizations, evaluation of GSSs is becoming increasingly important. This paper reports the evaluation of an existing GSS. Our usability framework consists of nine dimensions: visual clarity, consistency, compatibility, informative feedback, explicitness, flexibility and control, error prevention and correction, ease of learning, and ease of use. We make use of the co-discovery method where teams of two participants perform tasks together while being observed. The study involves questionnaires and interview sessions. The strengths and weaknesses of the …

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Metaheuristics With Local Search Techniques For Retail Shelf-Space Optimization, Andrew Lim, Brian Rodrigues, Xingwen Zhang Jan 2004

Metaheuristics With Local Search Techniques For Retail Shelf-Space Optimization, Andrew Lim, Brian Rodrigues, Xingwen Zhang

Research Collection Lee Kong Chian School Of Business

Efficient shelf-space allocation can provide retailers with a competitive edge. While there has been little study on this subject, there is great interest in improving product allocation in the retail industry. This paper examines a practicable linear allocation model for optimizing shelf-space allocation. It extends the model to address other requirements such as product groupings and nonlinear profit functions. Besides providing a network flow solution, we put forward a strategy that combines a strong local search with a metaheuristic approach to space allocation. This strategy is flexible and efficient, as it can address both linear and nonlinear problems of realistic …

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Bias In The Correlated Uniqueness Model For Mtmm Data, James M. Conway, Filip Lievens, Steven E. Scullen, Charles E. Lance Jan 2004

Bias In The Correlated Uniqueness Model For Mtmm Data, James M. Conway, Filip Lievens, Steven E. Scullen, Charles E. Lance

Research Collection Lee Kong Chian School Of Business

This simulation investigates bias in trait factor loadings and intercorrelations when analyzing multitrait-multimethod (MTMM) data using the correlated uniqueness (CU) confirmatory factor analysis (CFA) model. A theoretical weakness of the CU model is the assumption of uncorrelated methods. However, previous simulation studies have shown little bias in trait estimates even when true method correlations are large. We hypothesized that there would be substantial bias when both method factor correlations and method factor loadings were large. We generated simulated sample data using population parameters based on our review of actual MTMM results. Results confirmed the prediction; substantial bias occurred in trait …

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Parameter Selection In Genetic Algorithms, Onur Boyabatli, Ihsan Sabuncuoglu Jan 2004

Parameter Selection In Genetic Algorithms, Onur Boyabatli, Ihsan Sabuncuoglu

Research Collection Lee Kong Chian School Of Business

In this study, we provide a new taxonomy of parameters of genetic algorithms (GA), structural and numerical parameters, and analyze the effect of numerical parameters on the performance of GA based simulation optimization applications with experimental design techniques. Appropriate levels of each parameter are proposed for a particular problem domain. Controversial to existing literature on GA, our computational results reveal that in the case of a dominant set of decision variable the crossover operator does not have a significant impact on the performance measures, whereas high mutation rates are more suitable for GA applications.

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Heuristics For A Brokering Set Packing Problem, Yunso Guo, Andrew Lim, Brian Rodrigues, Yi Zhu Jan 2004

Heuristics For A Brokering Set Packing Problem, Yunso Guo, Andrew Lim, Brian Rodrigues, Yi Zhu

Research Collection Lee Kong Chian School Of Business

In this paper we formulate the combinatorial auction brokering problem as a Set Packing Problem (SPP) and apply a simulated annealing heuristic to solve SPP. Experimental results are compared with a recent heuristic algorithm and also with the CPLEX Integer Programming solver where we found that the simulated annealing approach outperforms the previous heuristic method and CPLEX obtaining results within smaller timescales.

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A New Look At The Multiclass Network Equilibrium Problem, Patrice Marcotte, Laura Wynter Jan 2004

A New Look At The Multiclass Network Equilibrium Problem, Patrice Marcotte, Laura Wynter

Research Collection School Of Computing and Information Systems

The multiclass network equilibrium problem is expressed in general as a nonmonotone, asymmetric, variational inequality problem. We show that in spite of the nonmonotonicity of the cost operator, the problem may actually satisfy a weaker property, induced by the hierarchical nature of the travel cost interactions. This property allows a natural decomposition approach, not otherwise available, that admits provably convergent algorithms. We present one such algorithm, easily implementable using a solver for the single-class network equilibrium problem, together with a convergence proof.

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Java-Based Digital Library Portal For Geography Education, Zehua Liu, Hai Yuan, Ee Peng Lim, Ming Yin, Dion Hoe-Lian Goh, Yin-Leng Theng, Wee-Keong Ng Jan 2004

Java-Based Digital Library Portal For Geography Education, Zehua Liu, Hai Yuan, Ee Peng Lim, Ming Yin, Dion Hoe-Lian Goh, Yin-Leng Theng, Wee-Keong Ng

Research Collection School Of Computing and Information Systems

G-Portal is a Java-based digital library system for managing the metadata of geography related resources on the Web. In addition to providing a flexible repository subsystem to accommodate metadata of different formats using XML and XML Schemas, G-Portal organizes metadata into projects and layers, and supports an integrated and synchronized classification and map-based interfaces over the stored metadata. G-Portal also includes a classification subsystem that creates category structures and classifies metadata resources into categories based on user-specified classification schemas. Furthermore, G-Portal users can annotate resources and make their annotations available to others. In this paper, we describe the design and …

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Viscors: A Visual-Content Recommender For The Mobile Web, Chan Young Kim, Jae Kyu Lee, Yoon Ho Cho, Deok Hwan Kim Jan 2004

Viscors: A Visual-Content Recommender For The Mobile Web, Chan Young Kim, Jae Kyu Lee, Yoon Ho Cho, Deok Hwan Kim

Research Collection School Of Computing and Information Systems

Current search methods for mobile-Web content can be frustrating to use. To shorten searches for cell phone wallpaper images, VISCORS combines collaborative filtering with content-based image retrieval. An increasing selection of content is becoming available in the mobile-Web environment, where users navigate the Web using wireless devices such as cell phones and PDAs. The fast growth and excellent prospects of the mobile-Web content market have attracted many content providers.

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Supply Chains Integration: Architecture And Enabling Technologies, Keng Siau, Yuhong Tian Jan 2004

Supply Chains Integration: Architecture And Enabling Technologies, Keng Siau, Yuhong Tian

Research Collection School Of Computing and Information Systems

An effective and efficient supply chain is vital to the competitiveness and the survival of an organization. With the emergence of the e-business era, supply chain systems need to be able to extend beyond the traditional boundaries. This paper proposes integrated supply chain architecture (SCA) that combines the benefits of Enterprise Resource Planning (ERP) and the various supply chain applications. Some necessary criteria for an integrated supply chain include completeness, security, flexibility, scalability, and interoperability. The enabling technologies for such a supply chain system include XML, DCOM, CORBA, SOAP, Net, and Semantic Web. Wireless and mobile technologies could further extend …

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Logistics Outsourcing And 3pl Challenges, Michelle L. F. Cheong Jan 2004

Logistics Outsourcing And 3pl Challenges, Michelle L. F. Cheong

Research Collection School Of Computing and Information Systems

Logistics has been an important part of every economy and every business entity. The worldwide trend in globalization has led to many companies outsourcing their logistics function to Third-Party Logistics (3PL) companies, so as to focus on their core competencies. This paper attempts to broadly identify and categorize the challenges faced by 3PL companies and discover potential gaps for future research. Some of the challenges will be related with the experience and information collected from interviews with two 3PL companies.

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Congestion Control And Vehicle Ownership Restriction: The Choice Of An Optimal Quota Policy, Winston T. H. Koh Jan 2004

Congestion Control And Vehicle Ownership Restriction: The Choice Of An Optimal Quota Policy, Winston T. H. Koh

Research Collection School Of Economics

Singapore introduced a vehicle quota system (VQS) in 1990 as part of its overall policy to control urban congestion. While the VQS has reduced the annual growth rate of the vehicle population to about 3 per cent, it has created uncertainty in the cost of vehicle ownership due to the fluctuations in licence prices. This paper discusses three issues relating to the optimal design of a VQS: licence transferability, sub-categorisation, and the choice of an auction format. The analysis shows that licence transferability is not unambiguously desirable, sub-categorisation is highly regressive, and an open auction format results in less aggressive …

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Deviance Information Criterion For Comparing Stochastic Volatility Models, Andreas Berg, Renate Meyer, Jun Yu Jan 2004

Deviance Information Criterion For Comparing Stochastic Volatility Models, Andreas Berg, Renate Meyer, Jun Yu

Research Collection School Of Economics

Bayesian methods have been efficient in estimating parameters of stochastic volatility models for analyzing financial time series. Recent advances made it possible to fit stochastic volatility models of increasing complexity, including covariates, leverage effects, jump components, and heavy-tailed distributions. However, a formal model comparison via Bayes factors remains difficult. The main objective of this article is to demonstrate that model selection is more easily performed using the deviance information criterion (DIC). It combines a Bayesian measure of fit with a measure of model complexity. We illustrate the performance of DIC in discriminating between various different stochastic volatility models using simulated …

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Qos Routing Optimization Strategy Using Genetic Algorithm In Optical Fiber Communication Networks, Zhaoxia Wang, Zengqiang Chen, Zhuzhi Yuan Jan 2004

Qos Routing Optimization Strategy Using Genetic Algorithm In Optical Fiber Communication Networks, Zhaoxia Wang, Zengqiang Chen, Zhuzhi Yuan

Research Collection School Of Computing and Information Systems

This paper describes the routing problems in optical fiber networks, defines five constraints, induces and simplifies the evaluation function and fitness function, and proposes a routing approach based on the genetic algorithm, which includes an operator [OMO] to solve the QoS routing problem in optical fiber communication networks. The simulation results show that the proposed routing method by using this optimal maintain operator genetic algorithm (OMOGA) is superior to the common genetic algorithms (CGA). It not only is robust and efficient but also converges quickly and can be carried out simply, that makes it better than other complicated GA.

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Analysis Of A Yield Management Model For On Demand Computing Centers, Yezekael Hayel, Laura Wynter, Parijat Dube Jan 2004

Analysis Of A Yield Management Model For On Demand Computing Centers, Yezekael Hayel, Laura Wynter, Parijat Dube

Research Collection School Of Computing and Information Systems

The concept of yield management for IT infrastructures, and in particular for on demand IT utilities was recently introduced in [17]. The present paper provides a detailed analysis of that model, both in simplified cases where an analytical analysis is possible, and numerically on larger problem instances, and confirms the significant revenue benefit that can accrue through use of yield management in an IT on demand operating environment.

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Paper For An Educational Digital Library, Dion Hoe-Lian Goh, Yin-Leng Theng, Ming Yin, Ee Peng Lim Dec 2003

Paper For An Educational Digital Library, Dion Hoe-Lian Goh, Yin-Leng Theng, Ming Yin, Ee Peng Lim

Research Collection School Of Computing and Information Systems

GeogDL is a digital library of geography examination resources designed to assist students in revising for a national geography examination in Singapore. As part of an iterative design process, we carried out participatory design and brainstorming with student and teacher design partners. The first study involved prospective student design partners. In response to the first study, we describe in this paper an implementation of PAPER – Personalised Adaptive Pathways for Exam Resources – a new bundle of personalized, interactive services containing a mock exam and a personal coach. The mock exam provides a simulation of the actual geography examination while …

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Structuring Lecture Videos For Distance Learning Applications, Chong-Wah Ngo, Feng Wang, Ting-Chuen Pong Dec 2003

Structuring Lecture Videos For Distance Learning Applications, Chong-Wah Ngo, Feng Wang, Ting-Chuen Pong

Research Collection School Of Computing and Information Systems

This paper presents an automatic and novel approach in structuring and indexing lecture videos for distance learning applications. By structuring video content, we can support both topic indexing and semantic querying of multimedia documents. In this paper, our aim is to link the discussion topics extracted from the electronic slides with their associated video and audio segments. Two major techniques in our proposed approach include video text analysis and speech recognition. Initially, a video is partitioned into shots based on slide transitions. For each shot, the embedded video texts are detected, reconstructed and segmented as high-resolution foreground texts for commercial …

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Development Of A Framework For Trust In Mobile Commerce, J. Erickson, Keng Siau Dec 2003

Development Of A Framework For Trust In Mobile Commerce, J. Erickson, Keng Siau

Research Collection School Of Computing and Information Systems

Mobile commerce represents a significant development in e-commerce. Despite the potential of mobile commerce, trust is a major obstacle in its adoption and development. The focus of this research is to develop a framework to identify the factors influencing trust in mobile commerce and to explain the development of such trust using a means-ends objective network. We utilized the Value- Focused Thinking approach to interview subjects in order to identify their fundamental and means objectives concerning trust in mobile commerce and to construct a means-ends objective network. A trust framework is developed from the means-ends objective network. As one of …

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Xstamps: A Multiversion Timestamps Concurrency Control Protocol For Xml Data, Khin-Myo Win, Wee-Keong Ng, Ee Peng Lim Dec 2003

Xstamps: A Multiversion Timestamps Concurrency Control Protocol For Xml Data, Khin-Myo Win, Wee-Keong Ng, Ee Peng Lim

Research Collection School Of Computing and Information Systems

With the tremendous growth of XML data over the Web, efficient management of such data becomes a new challenge for database community. Several data management solutions, proposed in recent years, extend the capability of traditional database systems to meet the needs of XML data while alternative approaches introduce new generation databases, named as native XML database management systems. Although traditional databases have mature transaction management and concurrency control techniques, there is still a need to tailor techniques for native XML databases in order to deal with distinct characteristics of XML. In this paper, we propose XStamps, a multiversion timestamps concurrency …

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To Pester Or Leave Alone: Lifetime Value Maximization Through Optimal Communication Timing, Xavier Dreze, Andre Bonfrer Dec 2003

To Pester Or Leave Alone: Lifetime Value Maximization Through Optimal Communication Timing, Xavier Dreze, Andre Bonfrer

Research Collection Lee Kong Chian School Of Business

The marketing literature has long acknowledged the importance of a customer’s lifetime value in customer relationship management. More recently, researchers have turned their attention to the links between satisfaction and both customer acquisition and retention strategies. In this paper, we are interested in understanding the impact of communication frequency on customer retention and ultimately on lifetime value. We develop a theoretical framework for managing a customer database and addressing the tradeoffs between value extraction and customer retention. An empirical application of this framework is conducted for permission-based email marketing in the entertainment industry. This application recognizes the customization ability underlying …

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Nurse Rostering Problems: A Bibliographic Survey, Brenda Cheang, Haibing Li, Andrew Lim, Brian Rodrigues Dec 2003

Nurse Rostering Problems: A Bibliographic Survey, Brenda Cheang, Haibing Li, Andrew Lim, Brian Rodrigues

Research Collection Lee Kong Chian School Of Business

Hospitals need to repeatedly produce duty rosters for its nursing staff. The good scheduling of nurses has impact on the quality of health care, the recruitment of nurses, the development of budgets and other nursing functions. The nurse rostering problem (NRP) has been the subject of much study. This paper presents a brief overview, in the form of a bibliographic survey, of the many models and methodologies available to solve the NRP.

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Design And Analysis Of Cylindrical Antiresonant Reflecting Optical Waveguide, Chyng Wen Tee, S. F. Yu Dec 2003

Design And Analysis Of Cylindrical Antiresonant Reflecting Optical Waveguide, Chyng Wen Tee, S. F. Yu

Research Collection Lee Kong Chian School Of Business

A field-transfer matrix method is developed to analyze the modal characteristics of cylindrical multilayered waveguides with axis-symmetric geometry. A new design rule for cylindrical antiresonant reflecting optical waveguides (ARROWs), based on a three-step design process, is also proposed to minimize the radiation loss of the fundamental leaky mode. In addition, a simple approach is suggested to estimate the optimum core diameter of the cylindrical ARROWs for optimum radiation loss and radiation loss margin. Hence, it can be shown that an extra high index cladding layer is good enough to reduce the radiation loss as well as to maintain a reasonably …

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A Fit-Gap Analysis Of E-Business Curricula Vs. Industry Need, S. Davis, Keng Siau, K. Dhenuvakonda Dec 2003

A Fit-Gap Analysis Of E-Business Curricula Vs. Industry Need, S. Davis, Keng Siau, K. Dhenuvakonda

Research Collection School Of Computing and Information Systems

The alignment of e-business academic programs with the e-business market is examined using a fit-gap analysis. Two high-end business schools, ranked independently by US News and Business Week, were chosen as sample. A total of 391 different e-commerce courses were identified, which were classified into 24 categories. Out of these, there are two broad and distinct tracks in e-business curricula, with one track paving the way for an e-business career with a prevailing focus on the business aspect and the other track leading to a career focusing on technology and Web-based systems development. Industry demand for e-business professionals and the …

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Creating A Virtual Store Image, P. Katerattanakul, Keng Siau Dec 2003

Creating A Virtual Store Image, P. Katerattanakul, Keng Siau

Research Collection School Of Computing and Information Systems

A study was conducted to describe some of the factors that needed to be considered for a virtual store. It was revealed that the growth of e-commerce and online businesses has made it essential to understand the critical attributes of image for a virtual store. Store image was described as the way in which the store was defined by customers and several studies. The study compiled 77 designs and features into a list used to construct a survey. Four hundred and twenty-seven potential customers were requested to rate the significance of each item on the list. The information gathered identified …

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Score Tests For Inverse Gaussian Mixture, Zhenlin Yang Dec 2003

Score Tests For Inverse Gaussian Mixture, Zhenlin Yang

Research Collection School Of Economics

The mixed inverse Gaussian given by Whitmore (Scand. J. Statist., 13, 1986, 211–220) provides a convenient way for testing the goodness-of-fit of a pure inverse Gaussian distribution. The test is a one-sided score test with the null hypothesis being the pure inverse Gaussian (i.e. the mixing parameter is zero) and the alternative a mixture. We devise a simple score test and study its finite sample properties. Monte Carlo results show that it compares favourably with the smooth test of Ducharme (Test, 10, 2001, 271-290). In practical applications, when the pure inverse Gaussian distribution is rejected, one is interested in making …

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