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Articles 8221 - 8250 of 9003

Full-Text Articles in Computer Sciences

Tacit Knowledge, Nonaka And Takeuchi Seci Model And Informal Knowledge Processes, Siu Loon Hoe Mar 2006

Tacit Knowledge, Nonaka And Takeuchi Seci Model And Informal Knowledge Processes, Siu Loon Hoe

Research Collection School Of Computing and Information Systems

The organizational behavior and knowledge management literature has devoted a lot attention on how structural knowledge processes enhance learning. There has been little emphasis on the informal knowledge processes and the construct remains undefined. The purpose of this paper is to highlight the importance of informal knowledge processes, propose a definition for these processes and link them to the socialization and internalization processes suggested by Nonaka and Takeuchi in the SECI model. The paper offers a fresh perspective on how informal knowledge processes in organizations help to enhance the organization’s learning capability. It will enable scholars and managers to have …

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A Hybrid Scatter Search/Electromagnetism Meta-Heuristic For Project Scheduling, Dieter Debels, Bert De Reyck, Roel Leus, Mario Vanhoucke Mar 2006

A Hybrid Scatter Search/Electromagnetism Meta-Heuristic For Project Scheduling, Dieter Debels, Bert De Reyck, Roel Leus, Mario Vanhoucke

Research Collection Lee Kong Chian School Of Business

In the last few decades, several effective algorithms for solving the resource-constrained project scheduling problem have been proposed. However, the challenging nature of this problem, summarised in its strongly NP-hard status, restricts the effectiveness of exact optimisation to relatively small instances. In this paper, we present a new meta-heuristic for this problem, able to provide near-optimal heuristic solutions for relatively large instances. The procedure combines elements from scatter search, a generic population-based evolutionary search method, and from a recently introduced heuristic method for the optimisation of unconstrained continuous functions based on an analogy with electromagnetism theory. We present computational …

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Fortifying Password Authentication In Integrated Healthcare Delivery Systems, Yanjiang Yang, Robert H. Deng, Feng Bao Mar 2006

Fortifying Password Authentication In Integrated Healthcare Delivery Systems, Yanjiang Yang, Robert H. Deng, Feng Bao

Research Collection School Of Computing and Information Systems

Integrated Delivery Systems (IDSs) now become a primary means of care provision in healthcare domain. However, existing password systems (under either the single-server model or the multi-server model) do not provide adequate security when applied to IDSs. We are thus motivated to present a practical password authentication system built upon a novel two-server model. We generalize the two-server model to an architecture of a single control server supporting multiple service servers, tailored to the organizational structure of IDSs. The underlying user authentication and key exchange protocols we propose are password-only, neat, efficient, and robust against off-line dictionary attacks mounted by …

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Robust Classification Of Eeg Signal For Brain-Computer Interface, Manoj Thulasidas, Cuntai Guan, Jiankang Wu Mar 2006

Robust Classification Of Eeg Signal For Brain-Computer Interface, Manoj Thulasidas, Cuntai Guan, Jiankang Wu

Research Collection School Of Computing and Information Systems

We report the implementation of a text input application (speller) based on the P300 event related potential. We obtain high accuracies by using an SVM classifier and a novel feature. These techniques enable us to maintain fast performance without sacrificing the accuracy, thus making the speller usable in an online mode. In order to further improve the usability, we perform various studies on the data with a view to minimizing the training time required. We present data collected from nine healthy subjects, along with the high accuracies (of the order of 95% or more) measured online. We show that the …

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Crosscutting Score: An Indicator Metric For Aspect Orientation, Subhajit Datta Mar 2006

Crosscutting Score: An Indicator Metric For Aspect Orientation, Subhajit Datta

Research Collection School Of Computing and Information Systems

Aspect Oriented Programming (AOP) provides powerful techniques for modeling and implementing enterprise software systems. To leverage its full potential, AOP needs to be perceived in the context of existing methodologies such as Object Oriented Programming (OOP). This paper addresses an important question for AOP practitioners - how to decide whether a component is best modeled as a class or an aspect? Towards that end, we present an indicator metric, the Crosscutting Score and a method for its calculation and interpretation. We will illustrate our approach through a sample calculation.

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Publicly Verifiable Ownership Protection For Relational Databases, Yingjiu Li, Robert H. Deng Mar 2006

Publicly Verifiable Ownership Protection For Relational Databases, Yingjiu Li, Robert H. Deng

Research Collection School Of Computing and Information Systems

Today, watermarking techniques have been extended from the multimedia context to relational databases so as to protect the ownership of data even after the data are published or distributed. However, all existing watermarking schemes for relational databases are secret key based, thus require a secret key to be presented in proof of ownership. This means that the ownership can only be proven once to the public (e.g., to the court). After that, the secret key is known to the public and the embedded watermark can be easily destroyed by malicious users. Moreover, most of the existing techniques introduce distortions to …

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Agility Measurement Index: A Metric For The Crossroads Of Software Development Methodologies, Subhajit Datta Mar 2006

Agility Measurement Index: A Metric For The Crossroads Of Software Development Methodologies, Subhajit Datta

Research Collection School Of Computing and Information Systems

Software engineering's journey to maturity has been marked by the advent of different development methodologies. While each paradigm has its context and cognoscenti, project teams are often faced with the choice of one approach over another in the grind of delivering software on time and within budget. In this paper, we briefly review the three major techniques of addressing enterprise software development, namely the Waterfall, Unified and Extreme styles. The metric Agility Measurement Index is then proposed, which helps organizations choose the methodology that best suites a particular project.

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Threading And Autodocumenting News Videos: A Promising Solution To Rapidly Browse News Topics, Xiao Wu, Chong-Wah Ngo, Qing Li Mar 2006

Threading And Autodocumenting News Videos: A Promising Solution To Rapidly Browse News Topics, Xiao Wu, Chong-Wah Ngo, Qing Li

Research Collection School Of Computing and Information Systems

This paper describes the techniques in threading and autodocumenting news stories according to topic themes. Initially, we perform story clustering by exploiting the duality between stories and textual-visual concepts through a co-clustering algorithm. The dependency among stories of a topic is tracked by exploring the textual-visual novelty and redundancy of stories. A novel topic structure that chains the dependencies of stories is then presented to facilitate the fast navigation of the news topic. By pruning the peripheral and redundant news stories in the topic structure, a main thread is extracted for autodocumentary

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Caps: Energy-Efficient Processing Of Continuous Aggregate Queries In Sensor Networks, Wen Hu, Archan Misra, Rajiv Shorey Mar 2006

Caps: Energy-Efficient Processing Of Continuous Aggregate Queries In Sensor Networks, Wen Hu, Archan Misra, Rajiv Shorey

Research Collection School Of Computing and Information Systems

In this paper, we design and evaluate an energy efficient data retrieval architecture for continuous aggregate queries in wireless sensor networks. We show how the modification of precision in one sensor affects the sample-reporting frequency of other sensors, and how the precisions of a group of sensors may be collectively modified to achieve the target quality of information (QoI) with higher energy-efficiency. The proposed collective adaptive precision setting (CAPS) architecture is then extended to exploit the observed temporal correlation among successive sensor samples for even greater energy efficiency. Detailed simulations with synthetic and real data traces demonstrate how the combination …

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Energy Efficiency And Capacity For Tcp Traffic In Multi-Hop Wireless Networks, Sorav Bansal, Rajeev Shorey, Rajeev Gupta, Archan Misra Feb 2006

Energy Efficiency And Capacity For Tcp Traffic In Multi-Hop Wireless Networks, Sorav Bansal, Rajeev Shorey, Rajeev Gupta, Archan Misra

Research Collection School Of Computing and Information Systems

We study the performance metrics associated with TCP-regulated traffic in multi-hop, wireless networks that use a common physical channel (e.g., IEEE 802.11). In contrast to earlier analyses, we focus simultaneously on two key operating metrics—the energy efficiency and the transport-layer (TCP) throughput. Using analysis and simulations, we show how these metrics are strongly influenced by the radio transmission range of individual nodes. Due to tradeoffs between the individual packet transmission energy and the likelihood of retransmissions, the total energy consumption is a convex function of the number of hops (and hence, of the transmission range). On the other hand, the …

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Scalable Authentication Of Mpeg-4 Streams, Yongdong Wu, Robert H. Deng Feb 2006

Scalable Authentication Of Mpeg-4 Streams, Yongdong Wu, Robert H. Deng

Research Collection School Of Computing and Information Systems

This paper presents three scalable and efficient schemes for authenticating MPEG-4 streams: the Flat Authentication Scheme, the Progressive Authentication Scheme, and the Hierarchical Authentication Scheme. All the schemes allow authentication of MPEG-4 streams over lossy networks by integrating seamlessly digital signatures and erasure correction coding with MPEG-4's fine granular scalability. A prominent feature of our schemes is their "sign once, verify many ways" property, i.e., they generate only one digital signature per compressed MPEG-4 object group, but allow clients to verify the authenticity of any down-scaled version of the original signed object group.

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Design Synthesis From Interaction And State-Based Specifications, Jun Sun, Jin Song Dong Jan 2006

Design Synthesis From Interaction And State-Based Specifications, Jun Sun, Jin Song Dong

Research Collection School Of Computing and Information Systems

Interaction-based and state-based modeling are two complementary approaches of behavior modeling. The former focuses on global interactions between system components. The latter concentrates on the internal states of individual components. Both approaches have been proven useful in practice. One challenging and important research objective is to combine the modeling power of both effectively and then use the combination as the basis for automatic design synthesis. We present a combination of interaction-based and state-based modeling, namely, Live Sequence Charts and Z, for system specification. We then propose a way of generating distributed design from the combinations. Our approach handles systems with …

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Efficient Mining Of Group Patterns From User Movement Data, Yida Wang, Ee Peng Lim, San-Yih Hwang Jan 2006

Efficient Mining Of Group Patterns From User Movement Data, Yida Wang, Ee Peng Lim, San-Yih Hwang

Research Collection School Of Computing and Information Systems

In this paper, we present a new approach to derive groupings of mobile users based on their movement data. We assume that the user movement data are collected by logging location data emitted from mobile devices tracking users. We formally define group pattern as a group of users that are within a distance threshold from one another for at least a minimum duration. To mine group patterns, we first propose two algorithms, namely AGP and VG-growth. In our first set of experiments, it is shown when both the number of users and logging duration are large, AGP and VG-growth are …

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Advances In Data Modeling Research, G. Allen, A. Bajaj, V. Khatri, S. Ram, Keng Siau Jan 2006

Advances In Data Modeling Research, G. Allen, A. Bajaj, V. Khatri, S. Ram, Keng Siau

Research Collection School Of Computing and Information Systems

In this paper, we summarize the discussions of the panel on "Advances in Data Modeling Research," held at the Americas Conference on Information Systems (AMCIS) in 2005. We focus on four primary areas where data modeling research offers rich opportunities: spatio-temporal semantics, genome research, ontological analysis and empirical evaluation of existing models. We highlight past work in each area and also discuss open questions, with a view to promoting future research in the overall data modeling area.

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Towards Better Quality Specification Miners, David Lo, Siau-Cheng Khoo Jan 2006

Towards Better Quality Specification Miners, David Lo, Siau-Cheng Khoo

Research Collection School Of Computing and Information Systems

Softwares are often built without specification. Tools to automatically extract specification from software are needed and many techniques have been proposed. One type of these specifications – temporal API specification – is often specified in the form of automaton (i.e., FSA/PFSA). There have been many work on mining software temporal specification using dynamic analysis techniques; i.e., analysis of software program traces. Unfortunately, the issues of scalability, robustness and accuracy of these techniques have not been comprehensively addressed. In this paper, we describe a framework that enables assessments of the performance of a specification miner in generating temporal specification of software …

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Visualization For Analyzing Trajectory-Based Metaheuristic Search Algorithms, Steven Halim, Roland H. C. Yap, Hoong Chuin Lau Jan 2006

Visualization For Analyzing Trajectory-Based Metaheuristic Search Algorithms, Steven Halim, Roland H. C. Yap, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

No abstract provided.

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Using Social Development Lenses To Understand E-Government Development, Keng Siau, Y. Long Jan 2006

Using Social Development Lenses To Understand E-Government Development, Keng Siau, Y. Long

Research Collection School Of Computing and Information Systems

As governments at different levels and all around the world are increasingly using the Web to enhance and improve their services, understanding e-government development and exploring factors that affect e-government development have become important research topics. The purpose of this research is to investigate factors explaining e-government development in terms of social development lenses. Based on growth and regional development theories, the paper hypothesizes that income level, development status, and region are three factors that differentiate e- government development in countries. Group comparison tests are conducted using secondary data from the United Nations and the United Nations Development Programme. The …

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Transition Rule Elicitation Methods For Urban Cellular Automata Models, Junfeng Jiao, Luc Boerboom Jan 2006

Transition Rule Elicitation Methods For Urban Cellular Automata Models, Junfeng Jiao, Luc Boerboom

Research Collection College of Integrative Studies

In this chapter, transition rules used in urban CA models are reviewed and classified into two categories: transition potential rules and conflict resolution rules. Then, four widely used rule elicitation methods: Regression analysis, Artificial Neural network (ANN), Visual calibration, and Analytical Hierarchy Processing – Multi Criteria Evaluation (AHP-MCE) are discussed. Most of these methods are data driven methods and can be used to elicit the transition potential rules in the urban CA models. In the following, three possible rule elicitation methods: Interview, Document analysis, and Card sorting are explained and demonstrated. These three methods are driven by knowledge and can …

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In-Network Join Processing For Sensor Networks, Hai Yu, Ee Peng Lim, Jun Zhang Jan 2006

In-Network Join Processing For Sensor Networks, Hai Yu, Ee Peng Lim, Jun Zhang

Research Collection School Of Computing and Information Systems

Recent advances in hardware and wireless technologies have led to sensor networks consisting of large number of sensors capable of gathering and processing data collectively. Query processing on these sensor networks has to consider various inherent constraints. While simple queries such as select and aggregate queries in wireless sensor networks have been addressed in the literature, the processing of join queries in sensor networks remains to be investigated. In this paper, we present a synopsis join strategy for evaluating join queries in sensor networks with communication efficiency. In this strategy, instead of directly joining two relations distributed in a sensor …

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The Impact Of Financial Market And Resale Market On Firm Strategies, Zhiling Guo, Andrew B. Whinston Jan 2006

The Impact Of Financial Market And Resale Market On Firm Strategies, Zhiling Guo, Andrew B. Whinston

Research Collection School Of Computing and Information Systems

The ever-increasing use of information technology (IT) in business transactions greatly expands firms? exposure to different electronic markets. This paper provides a framework to understand how firms can leverage different strategies across external financial markets and an internal resale market to improve overall profitability. We develop a model in which a group of risk-averse retailers sell a homogeneous product to their respective uncertain consumer markets. We study a scenario where an internal resale market can be constructed among the retailers and outside financial markets can be used to improve their ability to manage uncertainty. We identify strategies for retailers operating …

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Using Cognitive Mapping Techniques To Supplement Uml And Up In Information Requirements Determination, Keng Siau, Tan Xin Jan 2006

Using Cognitive Mapping Techniques To Supplement Uml And Up In Information Requirements Determination, Keng Siau, Tan Xin

Research Collection School Of Computing and Information Systems

Information requirements determination is a critical task in system development projects. Many human issues may hinder the efforts to accurately capture and clearly understand users' information requirements. In this paper, we review the cognitive underpinnings of some human issues, which are discussed in existing literature and relevant to information requirements determination. We then propose the use of cognitive mapping techniques in the process of information requirements determination. Three widely used cognitive mapping techniques - causal mapping, semantic mapping, and concept mapping – are briefly introduced in this article. A case is used to illustrate how to use these cognitive mapping …

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E-Healthcare In Abc County Health Department (Abcchd): Trade-Offs Analysis And Evaluation, Keng Siau, Hwee-Joo Kam Jan 2006

E-Healthcare In Abc County Health Department (Abcchd): Trade-Offs Analysis And Evaluation, Keng Siau, Hwee-Joo Kam

Research Collection School Of Computing and Information Systems

The issue of privacy stirred a tumultuous uproar when the ABC County Health Department (ABCCHD) was planning for an e-Healthcare system that utilized information technology to streamline the administration process of patients. ABCCHD had hired a software vendor, Info-Health, a company that specialized in information system development for the healthcare industry to help in the project. The privacy of patients with Sexually Transmitted Diseases/Human Immunity System was a thorny issue in the implementation of the e-Healthcare system. A trade-off between privacy and cost was discussed and debated. Three alternatives, with varying degrees of privacy and cost, were considered.

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Systems Analysis & Design: An Essential Part Of Is Education, Albert L. Harris, Michael Lang, Briony J. Oates, Keng Siau Jan 2006

Systems Analysis & Design: An Essential Part Of Is Education, Albert L. Harris, Michael Lang, Briony J. Oates, Keng Siau

Research Collection School Of Computing and Information Systems

Systems analysis and design has been as critical building block in Information Systems (IS) education since the inception of the IS major. Whether it is taught using the traditional or "structured approach or the object-oriented approach, it exposes students to the different methods, tools, and techniques used in developing new systems, develops students analytical and problem-solving skills, teaches fact-finding and data gathering techniques, and provides teamwork skills. All of these are valuable skills for systems analysts. This paper introduces the reader of this special issue on systems analysis and design education to the issue, discusses the two approaches to teaching …

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The Roles Of Digital Libraries In Teaching And Learning Geography, Chew-Hung Chang, John Hedberg, Tiong-Sa Teh, Ee Peng Lim Jan 2006

The Roles Of Digital Libraries In Teaching And Learning Geography, Chew-Hung Chang, John Hedberg, Tiong-Sa Teh, Ee Peng Lim

Research Collection School Of Computing and Information Systems

Adopting a problem-centred approach helps students to learn Geography more effectively as they are able to identify and generalize about where different resources or activities are spatially located and they learn to associate certain patterns and processes with geographical changes. In an era where web-based student-centred inquiry is gaining popularity as a mode of learning Geography, the role of digital libraries as delivery trucks (in Clark’s terminology, 1983) needs to be better understood. An obvious affordance of the digital library is that it organizes information around themes for problems to be solved. This paper describes a developmental project to build …

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Multiagent Teamwork: Hybrid Approaches, Praveen Paruchuri, Emma Bowring, Ranjit Nair, Jonathan Pearce, Nathan Schurr, Milind Tambe, Pradeep Varakantham Jan 2006

Multiagent Teamwork: Hybrid Approaches, Praveen Paruchuri, Emma Bowring, Ranjit Nair, Jonathan Pearce, Nathan Schurr, Milind Tambe, Pradeep Varakantham

Research Collection School Of Computing and Information Systems

Today within the multiagent community, we see at least four competing methods to building multiagent systems: beliefdesireintention (BDI), distributed constraint optimization (DCOP), distributed POMDPs, and auctions or game-theoretic methods. While there is exciting progress within each approach, there is a lack of cross-cutting research. This article highlights the various hybrid techniques for multiagent teamwork developed by the teamcore group. In particular, for the past decade, the TEAMCORE research group has focused on building agent teams in complex, dynamic domains. While our early work was inspired by BDI, we will present an overview of recent research that uses DCOPs and distributed …

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Grid-Partition Index: A Hybrid Approach To Nearest-Neighbor Queries In Wireless Location-Based Services, Baihua Zheng, Jianliang Xu, Wang-Chien Lee, Dik Lun Lee Jan 2006

Grid-Partition Index: A Hybrid Approach To Nearest-Neighbor Queries In Wireless Location-Based Services, Baihua Zheng, Jianliang Xu, Wang-Chien Lee, Dik Lun Lee

Research Collection School Of Computing and Information Systems

Traditional nearest-neighbor (NN) search is based on two basic indexing approaches: object-based indexing and solution-based indexing. The former is constructed based on the locations of data objects: using some distance heuristics on object locations. The latter is built on a precomputed solution space. Thus, NN queries can be reduced to and processed as simple point queries in this solution space. Both approaches exhibit some disadvantages, especially when employed for wireless data broadcast in mobile computing environments. In this paper, we introduce a new index method, called the grid-partition index, to support NN search in both ondemand access and periodic broadcast …

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Webarc: Website Archival Using A Structured Approach, Ee Peng Lim, Maria Marissa Dec 2005

Webarc: Website Archival Using A Structured Approach, Ee Peng Lim, Maria Marissa

Research Collection School Of Computing and Information Systems

Website archival refers to the task of monitoring and storing snapshots of website(s) for future retrieval and analysis. This task is particularly important for websites that have content changing over time with older information constantly overwritten by newer one. In this paper, we propose WEBARC as a set of software tools to allow users to construct a logical structure for a website to be archived. Classifiers are trained to. determine relevant web pages and their categories, and subsequently used in website downloading. The archival schedule can be specified and executed by a scheduler. A website viewer is also developed to …

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New Efficient Mds Array Codes For Raid Part Ii: Rabin-Like Codes For Tolerating Multiple (>=4) Disk Failures, Gui-Liang Feng, Robert H. Deng, Feng Bao Dec 2005

New Efficient Mds Array Codes For Raid Part Ii: Rabin-Like Codes For Tolerating Multiple (>=4) Disk Failures, Gui-Liang Feng, Robert H. Deng, Feng Bao

Research Collection School Of Computing and Information Systems

A new class of Binary Maximum Distance Separable (MDS) array codes which are based on circular permutation matrices are introduced in this paper. These array codes are used for tolerating multiple (greater than or equal to 4) disk failures in Redundant Arrays of Inexpensive Disks (RAID) architecture. The size of the information part is m \times n, where n is the number of information disks and (m+1) is a prime integer; the size of the parity-check part is m \times r, the minimum distance is r+1, and the number of parity-check disks is r. In practical applications, m can be …

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Improving The Quality Of Conceptual Modeling Using Cognitive Mapping Techniques, Keng Siau, X. Tan Dec 2005

Improving The Quality Of Conceptual Modeling Using Cognitive Mapping Techniques, Keng Siau, X. Tan

Research Collection School Of Computing and Information Systems

Conceptual modeling involves the understanding and communication between system analysts and end-users. Many factors may affect the quality of conceptual modeling processes as well as the models per se. Human cognition plays a pivotal role in understanding these factors and cognitive mapping techniques are effective tools to elicit and represent human cognition. In this paper, we look at the use of cognitive mapping techniques to improve the quality of conceptual modeling. We review frameworks on quality in conceptual modeling and examine the role of human cognition in conceptual modeling. The paper also discusses how human cognition is related to quality …

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Giving Users The Steering Wheel For Guiding Resource-Adaptive Systems, Joao Sousa, Rajesh Krishna Balan, Vahe Poladian, David Garlan, Mahadev Satyanarayanan Dec 2005

Giving Users The Steering Wheel For Guiding Resource-Adaptive Systems, Joao Sousa, Rajesh Krishna Balan, Vahe Poladian, David Garlan, Mahadev Satyanarayanan

Research Collection School Of Computing and Information Systems

Addressing resource variation plays an increasingly important role in engineering today's software systems. Research in resource-adaptive applications takes an important step towards addressing this problem. However, existing solutions stop short of addressing the fact that different user tasks often have specific goals of quality of service, and that such goals often entail multiple aspects of quality of service. This paper presents a framework for engineering software systems capable of adapting to resource variations in ways that are specific to the quality goals of each user task. For that, users are empowered to specify their task-specific preferences with respect to multiple …

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