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Full-Text Articles in Physical Sciences and Mathematics

Technology Competition And Optimal Investment Timing: A Real Options Perspective, Robert J. Kauffman, X. Li Jan 2005

Technology Competition And Optimal Investment Timing: A Real Options Perspective, Robert J. Kauffman, X. Li

Research Collection School Of Computing and Information Systems

Companies often choose to defer irreversible investments to maintain valuable managerial flexibility in an uncertain world. For some technology-intensive projects, technology uncertainty plays a dominant role in affecting investment timing. This article analyzes the investment timing strategy for a firm that is deciding about whether to adopt one or the other of two incompatible and competing technologies.We develop a continuous-time stochastic model that aids in the determination of optimal timing for managerial adoption within the framework of real options theory. The model captures the elements of the decision-making process in such a way so as to provide managerial guidance in …


A Multi-Agent Approach For Solving Optimization Problems Involving Expensive Resources, Hoong Chuin Lau, H. Wang Jan 2005

A Multi-Agent Approach For Solving Optimization Problems Involving Expensive Resources, Hoong Chuin Lau, H. Wang

Research Collection School Of Computing and Information Systems

In this paper, we propose a multi-agent approach for solving a class of optimization problems involving expensive resources, where monolithic local search schemes perform miserably. More specifically, we study the class of bin-packing problems. Under our proposed Fine-Grained Agent System scheme, rational agents work both collaboratively and selfishly based on local search and mimic physics-motivated systems. We apply our approach to a generalization of bin-packing - the Inventory Routing Problem with Time Windows - which is an important logistics problem, and demonstrate the efficiency and effectiveness of our approach.


Robust Temporal Constraint Networks, Hoong Chuin Lau, Thomas Ou, Melvyn Sim Jan 2005

Robust Temporal Constraint Networks, Hoong Chuin Lau, Thomas Ou, Melvyn Sim

Research Collection School Of Computing and Information Systems

In this paper, we propose the Robust Temporal Constraint Network (RTCN) model for simple temporal constraint networks where activity durations are bounded by random variables. The problem is to determine whether such temporal network can be executed with failure probability less than a given 0 ≤ E ≤ 1 for each possible instantiation of the random variables, and if so. how one might find a feasible schedule with each given instantiation. The advantage of our model is that one can vary the value of ∊ to control the level of conservativeness of the solution. We present a computationally tractable and …


Partnering For Perfection: An Economics Perspective On B2b Electronic Market Strategic Alliances, Qizhi Dai, Robert J. Kauffman Jan 2005

Partnering For Perfection: An Economics Perspective On B2b Electronic Market Strategic Alliances, Qizhi Dai, Robert J. Kauffman

Research Collection School Of Computing and Information Systems

New technological innovations have made it possible for new intermediaries to create value in business processes that involve the procurement of manufacturing and services supplies. Associated with these innovations is the emergence of business-to-business (B2B) electronic markets. These act as digital intermediaries that aim to reduce the transaction costs and mitigate the risks inherent in procurement. They improve buyers’ capabilities to search for attractive prices and also serve to increase the liquidity of sellers’ products. In this chapter, the authors explore the evolution of B2B e-market firms in terms of the strategies they employ to “perfect” their value propositions and …


Two-Echelon Repairable Item Inventory System With Limited Repair Capacity Under Nonstationary Demands, Hoong Chuin Lau, Huawei Song Nov 2004

Two-Echelon Repairable Item Inventory System With Limited Repair Capacity Under Nonstationary Demands, Hoong Chuin Lau, Huawei Song

Research Collection School Of Computing and Information Systems

We study a repairable item inventory system under limited repair capacity and nonstationary Poisson demands, motivated by corrective maintenance of military equipment. Our goal is to minimize the cost of both spare and repair resource allocation. We propose an efficient analytical model that combines optimization modeling and queuing theory.


Job Scheduling With Unfixed Availability Constraints, Hoong Chuin Lau, C. Zhang Nov 2004

Job Scheduling With Unfixed Availability Constraints, Hoong Chuin Lau, C. Zhang

Research Collection School Of Computing and Information Systems

Standard scheduling theory assumes that all machines are continuously available throughout the planning horizon. In many manufacturing and service management situations however, machines need to be maintained periodically to prevent malfunctions. During the maintenance period, a machine is not available for processing jobs. Hence, a more realistic scheduling model should take into account machine maintenance activities. In this paper, we study the problem of job scheduling with unfixed availability constraints on a single machine. We first propose a preliminary classification for the scheduling problem with unfixed availability constraints based on maintenance constraints, job characteristics and objective function. We divide our …


Corrective Maintenance Optimization In An Air Force, Hoong Chuin Lau, K. Y. Neo, W. C. Wan Nov 2004

Corrective Maintenance Optimization In An Air Force, Hoong Chuin Lau, K. Y. Neo, W. C. Wan

Research Collection School Of Computing and Information Systems

Successful military mission planning and execution depend critically on equipment serviceability and resupply. Due to the stochastic nature of demands, the forecast of optimal spares and resources needed to guarantee the level of serviceability is a complex problem, especially in a multi-echelon setting. In this paper, we propose a decision-support concept and software tool known as Corrective Maintenance Optimizer (CMO) that helps to optimize system availability, through proper allocation of spare parts, both strategically and operationally.


Logistics Network Design With Differentiated Delivery Lead Time: A Chemical Industry Case Study, Michelle Lee Fong Cheong, Rohit Bhatnagar, Stephen C. Graves Nov 2004

Logistics Network Design With Differentiated Delivery Lead Time: A Chemical Industry Case Study, Michelle Lee Fong Cheong, Rohit Bhatnagar, Stephen C. Graves

Research Collection School Of Computing and Information Systems

Most logistics network design models assume exogenous customer demand that is independent of the service time or level. This paper examines the benefits of segmenting demand according to lead-time sensitivity of customers. To capture lead-time sensitivity in the network design model, we use a facility grouping method to ensure that the different demand classes are satisfied on time. In addition, we perform a series of computational experiments to develop a set of managerial insights for the network design decision making process.


A Development Framework For Rapid Metaheuristics Hybridization, Hoong Chuin Lau, M. K. Lim, W. C. Wan, S. Halim Sep 2004

A Development Framework For Rapid Metaheuristics Hybridization, Hoong Chuin Lau, M. K. Lim, W. C. Wan, S. Halim

Research Collection School Of Computing and Information Systems

While meta-heuristics are effective for solving large-scale combinatorial optimization problems, they result from time-consuming trial-and-error algorithm design tailored to specific problems. For this reason, a software tool for rapid prototyping of algorithms would save considerable resources. This work presents a generic software framework that reduces development time through abstract classes and software reuse, and more importantly, aids design with support of user-defined strategies and hybridization of meta-heuristics. Most interestingly, we propose a novel way of redefining hybridization with the use of the "request and response" metaphor, which form an abstract concept for hybridization. Different hybridization schemes can now be formed …


A Two-Level Framework For Coalition Formation Via Optimization And Agent Negotiation, Hoong Chuin Lau, Lei Zhang Sep 2004

A Two-Level Framework For Coalition Formation Via Optimization And Agent Negotiation, Hoong Chuin Lau, Lei Zhang

Research Collection School Of Computing and Information Systems

We present a two-level coalition formation approach based on a centralized optimization model on the upper level, and a distributed agent-negotiation model on the lower level. This approach allows us to balance agent self-interests against a high joint utility. Experimental results show that the two-level coalition formation mechanism will increase not only the overall utility of the coalition, but also the individual utility of most participating agents. The results also suggest it is better for the agents to be partially cooperative rather than either fully cooperative or self-interested in our setting.


Taking Dcop To The Real World: Efficient Complete Solutions For Distributed Event Scheduling, Rajiv Maheswaran, Milind Tambe, Emma Bowring, Jonathan Pearce, Pradeep Varakantham Jul 2004

Taking Dcop To The Real World: Efficient Complete Solutions For Distributed Event Scheduling, Rajiv Maheswaran, Milind Tambe, Emma Bowring, Jonathan Pearce, Pradeep Varakantham

Research Collection School Of Computing and Information Systems

Distributed Constraint Optimization (DCOP) is an elegant formalism relevant to many areas in multiagent systems, yet complete algorithms have not been pursued for real world applications due to perceived complexity. To capably capture a rich class of complex problem domains, we introduce the Distributed Multi-Event Scheduling (DiMES) framework and design congruent DCOP formulations with binary constraints which are proven to yield the optimal solution. To approach real-world efficiency requirements, we obtain immense speedups by improving communication structure and precomputing best case bounds. Heuristics for generating better communication structures and calculating bound in a distributed manner are provided and tested on …


Infosemm: Infosys It Security Maturity Model: A Report, Arcot Desai Narasimhalu, N. Dayasindhu, Raghavan Subramanian Jul 2004

Infosemm: Infosys It Security Maturity Model: A Report, Arcot Desai Narasimhalu, N. Dayasindhu, Raghavan Subramanian

Research Collection School Of Computing and Information Systems

Businesses are faced with a continuing battle related to cyber security related issues ranging from cyber attacks all the way to cyber (information) war. These issues affect result in information, system, reputation, and revenue related risks. These risks arise because of vulnerabilities introduced in three major parts of the enterprise – infrastructure, intelligence and practices. This report provides a rating system for representing the security health of enterprises.


Notes On Equilibria In Symmetric Games, Shih-Fen Cheng, Daniel M. Reeves, Yevgeniy Vorobeychik, Michael P. Wellman Jul 2004

Notes On Equilibria In Symmetric Games, Shih-Fen Cheng, Daniel M. Reeves, Yevgeniy Vorobeychik, Michael P. Wellman

Research Collection School Of Computing and Information Systems

In a symmetric game, every player is identical with respect to the game rules. We show that a symmetric 2strategy game must have a pure-strategy Nash equilibrium. We also discuss Nash’s original paper and its generalized notion of symmetry in games. As a special case of Nash’s theorem, any finite symmetric game has a symmetric Nash equilibrium. Furthermore, symmetric infinite games with compact, convex strategy spaces and continuous, quasiconcave utility functions have symmetric pure-strategy Nash equilibria. Finally, we discuss how to exploit symmetry for more efficient methods of finding Nash equilibria.


Proprietary And Open Systems Adoption In E-Procurement: A Risk-Augmented Transactions Cost Perspective, Robert J. Kauffman, Hamid Mohtadi Jun 2004

Proprietary And Open Systems Adoption In E-Procurement: A Risk-Augmented Transactions Cost Perspective, Robert J. Kauffman, Hamid Mohtadi

Research Collection School Of Computing and Information Systems

We present an economic model that enables the study of incentives for business-to-business (B2B) e-procurement systems investments that permit inventory coordination and improved operational control. We focus on the information technology adoption behavior of firms in the presence of transaction costs, agency costs and information uncertainty. We conclude that it is appropriate to rethink the prior theory and develop an extended transaction-cost theory perspective that incorporates the possibility of shocks. We distinguish among three kinds of B2B e-procurement systems platforms. Proprietary platform procurement systems involve traditional electronic data interchange (EDI) technologies. Open platform procurement systems are associated with e-market Web …


Multi-Period Multi-Dimensional Knapsack Problem And Its Application To Available-To-Promise, Hoong Chuin Lau, M. K. Lim May 2004

Multi-Period Multi-Dimensional Knapsack Problem And Its Application To Available-To-Promise, Hoong Chuin Lau, M. K. Lim

Research Collection School Of Computing and Information Systems

This paper is motivated by a recent trend in logistics scheduling, called Available-to-Promise. We model this problem as the multi-period multi-dimensional knapsack problem. We provide some properties for a special case of a single-dimensional problem. Based on insights obtained from these properties, we propose a two-phase heuristics for solving the multi-dimensional problem. We also propose a novel time-based ant colony optimization algorithm. The quality of the solutions generated is verified through experiments, where we demonstrate that the computational time is superior compared with integer programming to achieve solutions that are within a small percentage of the upper bounds.


A Cost-Effective Critical Path Approach For Service Priority Optimization In The Grid Computing Economy, Mei Lin, Zhangxi Lin Apr 2004

A Cost-Effective Critical Path Approach For Service Priority Optimization In The Grid Computing Economy, Mei Lin, Zhangxi Lin

Research Collection School Of Computing and Information Systems

The advancement in the utilization and technologiesof the Internet has led to the rapid growth of gridcomputing; and the perpetuating demand for gridcomputing resources calls for an incentive-compatible solution to the imminent QoS problem. This paper examines the optimal service priority selection problem that a grid computing network user will confront. We model grid services for a multi-subtask request as a prioritized PERT graph and prove that the localized conditional critical path, which is based on the cost-minimizin gpriority selection for each node, sets the lower bound for the length of cost-effective critical path that commits the optimal solution. We …


The Evolution Of Research On Information Systems: A Fiftieth Year Survey Of The Literature In Management Science, Rajiv D. Banker, Robert J. Kauffman Mar 2004

The Evolution Of Research On Information Systems: A Fiftieth Year Survey Of The Literature In Management Science, Rajiv D. Banker, Robert J. Kauffman

Research Collection School Of Computing and Information Systems

The development of the information systems (IS) literature in Management Science during the past 50 years reflects the inception, growth, and maturation of several different research streams. The five research streams we identify incorporate different definitions of the managerial problems that relate to IS, the alternate theoretical perspectives and different methodological paradigms to study them, and the levels of the organization at which their primary results impact managerial practice. The decision support and design science research stream studies the application of computers in decision support, control, and managerial decision making. The value of information research stream reflects relationships established based …


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.


Task Allocation Via Multi-Agent Coalition Formation: Taxonomy, Algorithms And Complexity, Hoong Chuin Lau, L. Zhang Nov 2003

Task Allocation Via Multi-Agent Coalition Formation: Taxonomy, Algorithms And Complexity, Hoong Chuin Lau, L. Zhang

Research Collection School Of Computing and Information Systems

Coalition formation has become a key topic in multiagent research. In this paper, we propose a preliminary classification for the coalition formation problem based on three driving factors (demands, resources and profit objectives). We divide our analysis into 5 cases. For each case, we present algorithms and complexity results. We anticipate that with future research, this classification can be extended in similar fashion to the comprehensive classification for the job scheduling problem.


Multi-Agent Coalition Via Autonomous Price Negotiation In A Real-Time Web Environment, Hoong Chuin Lau, Wei Sian Lim Oct 2003

Multi-Agent Coalition Via Autonomous Price Negotiation In A Real-Time Web Environment, Hoong Chuin Lau, Wei Sian Lim

Research Collection School Of Computing and Information Systems

In e-marketplaces, customers specify job requests in real-time and agents form coalitions to service them. This paper proposes a protocol for self-interested agents to negotiate prices in forming successful coalitions. We propose and experiment with two negotiation schemes: one allows information sharing while the other does not.


A Generic Object-Oriented Tabu Search Framework, Hoong Chuin Lau Jul 2003

A Generic Object-Oriented Tabu Search Framework, Hoong Chuin Lau

Research Collection School Of Computing and Information Systems

Presently, most tabu search designers devise their applications without considering the potential of design and code reuse, which consequently prolong the development of subsequent applications. In this paper, we propose a software solution known as Tabu Search Framework (TSF), which is a generic C++ software framework for tabu search implementation. The framework excels in code recycling through the use of a welldesigned set of generic abstract classes that clearly define their collaborative roles in the algorithm. Additionally, the framework incorporates a centralized process and control mechanism that enhances the search with intelligence. This results in a generic framework that is …


Strategyproof Mechanisms For Ad Hoc Network Formation, C. Jason Woodard, David C. Parkes Jun 2003

Strategyproof Mechanisms For Ad Hoc Network Formation, C. Jason Woodard, David C. Parkes

Research Collection School Of Computing and Information Systems

Agents in a peer-to-peer system typically have incentives to influence its network structure, either to reduce their costs or increase their ability to capture value. The problem is compounded when agents can join and leave the system dynamically. This paper proposes three economic mechanisms that offset the incentives for strategic behavior and facilitate the formation of networks with desirable global properties.


Modeling Product Development As A System Design Game, C. Jason Woodard Jun 2003

Modeling Product Development As A System Design Game, C. Jason Woodard

Research Collection School Of Computing and Information Systems

A system design game is a model of a situation in which agents’ actions determine the structure of a system, which in turn affects the system’s value and the share of value that each agent may capture through bargaining or market competition. This paper describes a class of games in which agents design interdependent products, for example software programs, which may be complements or substitutes for each other. These relationships are epresented by an object called a design structure network (DSN). Depending on the modeler’s choice of allocation rules, agents may benefit from owning critical nodes in the DSN, corresponding …


On The Strategy Of Supply Hubs For Cost Reduction And Responsiveness, Earl Barnes, Jim Dai, Shijie Deng, Doug Down, Mark Goh, Hoong Chuin Lau, Sharafali Moosa May 2003

On The Strategy Of Supply Hubs For Cost Reduction And Responsiveness, Earl Barnes, Jim Dai, Shijie Deng, Doug Down, Mark Goh, Hoong Chuin Lau, Sharafali Moosa

Research Collection School Of Computing and Information Systems

A supply hub is a location generally close to a manufacturer’s facility where all or some of its supplies are warehoused with the agreement that the materials will be paid for only when consumed. Supply hub is an innovative strategy employed by especially the electronics industry to achieve cost reduction and improved responsiveness. After first tracing the developments leading to the establishment of supply hubs, the paper then describes the dynamics of the operation of supply hubs. Case examples are provided to highlight the current practices. Finally, some research issues are identified.


Advances In Mobile Commerce Technologies, Ee Peng Lim, Keng Siau Jan 2003

Advances In Mobile Commerce Technologies, Ee Peng Lim, Keng Siau

Research Collection School Of Computing and Information Systems

No abstract provided.


Trading Agents Competing: Performance, Progress And Market Effectiveness, Michael P. Wellman, Shih-Fen Cheng, Daniel M. Reeves, Kevin M. Lochner Jan 2003

Trading Agents Competing: Performance, Progress And Market Effectiveness, Michael P. Wellman, Shih-Fen Cheng, Daniel M. Reeves, Kevin M. Lochner

Research Collection School Of Computing and Information Systems

The annual trading agent competition offers agent designers a forum for evaluating programmed trading techniques in a challenging market scenario. TAC aims to spur research by enabling researchers to compare techniques on a common problem and build on each other's ideas. A fixed set of assumptions and environment settings facilitates communication of methods and results. As a multiyear event, TAC lets researchers observe trading agents' progress over time, in effect accelerating the evolution of an adapted population of traders. Given all the participant effort invested, it is incumbent on us to learn as much from the experience as possible. After …


Integrating Local Search And Network Flow To Solve The Inventory Routing Problem, Hoong Chuin Lau, Q Liu, H. Ono Jul 2002

Integrating Local Search And Network Flow To Solve The Inventory Routing Problem, Hoong Chuin Lau, Q Liu, H. Ono

Research Collection School Of Computing and Information Systems

The inventory routing problem is one of important and practical problems in logistics. It involves the integration of inventory management and vehicle routing, both of which are known to be NP-hard. In this paper, we combine local search and network flows to solve the inventory management problem, by utilizing the minimum cost flow sub-solutions as a guiding measure for local search. We then integrate with a standard VRPTW solver to present experimental results for the overall inventory routing problem, based on instances extended from the Solomon benchmark problems.


Leadership Antecedents Of Informal Knowledge Acquisition And Dissemination, Siu Loon Hoe, Steve Mcshane Jul 2002

Leadership Antecedents Of Informal Knowledge Acquisition And Dissemination, Siu Loon Hoe, Steve Mcshane

Research Collection School Of Computing and Information Systems

Knowledge management is emerging as one of the leading influences on an organisation’s survival and competitive advantage (Blumentritt & Johnston 1999). Knowledge management is concerned with the effective acquisition, sharing, storage and utilisation of knowledge (Huber 1991; Saffady 1998). Corporate leaders are increasingly aware of the notion that an organisation’s long-term survival depends on its ability to generate new knowledge and continuously learn from the environment. The importance of a superior organisational learning capability as a source of competitive advantage is a common refrain among both managers and scholars (e.g. Kohli & Jaworski 1990; Nonaka 1991; Quinn 1992; Slater & …


Combining Two Heuristics To Solve A Supply Chain Optimization Problem, Hoong Chuin Lau, Yuyue Song Jul 2002

Combining Two Heuristics To Solve A Supply Chain Optimization Problem, Hoong Chuin Lau, Yuyue Song

Research Collection School Of Computing and Information Systems

In this paper, we consider a real-life supply chain optimization problem concerned with supplying a product from multiple warehouses to multiple geographically dispersed retailers. Each retailer faces a deterministic and period-dependent demand over some finite planning horizon. The demand of each retailer is satisfied by the supply from some predetermined warehouse through a fleet of vehicles which are only available within certain time windows at each period. Our goal is to identify a combined inventory and routing schedule such that the system-wide total cost over the planning horizon is minimised. This problem in essence is an amalgamation of two classical …


Product Schema Integration For Electronic Commerce: A Synonym Comparison Approach, Guanghao Yan, Wee-Keong Ng, Ee Peng Lim May 2002

Product Schema Integration For Electronic Commerce: A Synonym Comparison Approach, Guanghao Yan, Wee-Keong Ng, Ee Peng Lim

Research Collection School Of Computing and Information Systems

In any electronic commerce system, the heterogeneity of product descriptions is a critical impediment to efficient business information exchange. In the ABECOS electronic commerce system, buyer agents, seller agents, and directory agents liaise with one another in e-commerce activities. Only when agents have a common ontology of product descriptions (also called product schemas) are they able to interact seamlessly in e-commerce activities. This gives rise to the product schema integration problem (PSI); the problem of integrating heterogeneous schemas of a certain product into one globally compatible schema. We adopt an integration approach based on product attribute synonyms. We give a …