10 research outputs found
A Multi-Modal Public Transport Solution For Male, Maldives
Male, the island capital of the Maldives, an archipelago of over 1000 islands in the Indian Ocean faces chronic traffic congestion. This 2 sq km island is home to over 100,000 people. There is a taxi service comprising of around 450 vehicles and a dhoni (ferry) service amounting to over 100 vessels to neighbouring islands. Male, which is fast becoming a small urban centre faces typical peak period traffic issues. The vehicle fleet is dominated by motor cycles which still contribute to traffic congestion in narrow streets. The taxi system which comprises of individually owned taxis registered with a ‘call centre’, provide limited services but fails during peak demand periods especially on rainy days. There is very little coordination between the ferry and taxi services. The paper is based on the results of a detailed urban transport planning study carried out in Male Urban Area which included passenger interviews, vehicle counts and travel time surveys covering all modes of motorized and non-motorized travel. This paper investigates the introduction of a mini-bus transport system that would provide easy transfers between ferries and major traffic generators and attractors. The contribution of a mini-bus service in the long-term is also discussed with respect to implementation of traffic demand management measures. This paper discuses the most appropriate type of vehicle that could be used and the potential framework for ownership and management of such a system taking in to consideration the multi-modal connectivity and also the service parameters for the operation of a successful minibus service. The paper also analyses the present operation of the ferry services and investigates its ownership and operation parameters for efficiency and cost effectiveness. The paper reports reasons for the varied efficiencies seen on the different routes and the impact the informal and loosely regulated service providers have on the key performance indicators of these services. It also compares cost between different ferry services and studies the relationship between the ownership structure, technology levels, productivity and fare.Institute of Transport and Logistics Studies. Faculty of Economics and Business. The University of Sydne
Multi-Agent Simulation to Implementation: A Practical Engineering Methodology for Designing Space Flight Operations
Abstract. OCAMS is a practical engineering application of multi-agent systems technology, involving redesign of the tools and practices in a complex, distributed system. OCAMS is designed to assist flight controllers in managing interactions with the file system onboard the International Space Station. The “simulation to implementation ” development methodology combines ethnography, participatory design, multiagent simulation, and agent-based systems integration. We describe the model of existing operations and how it was converted into a future operations simulation that embeds a multiagent tool that automates part of the work. This hybrid simulation flexibly combines actual and simulated systems (e.g., mail) and objects (e.g., files) with simulated people, and is validated with actual data. A middleware infrastructure for agent societies is thus demonstrated in which agents are used to link arbitrary hardware and software systems to distributed teams of people on earth and in space—the first step in developing an interplanetary multiagent system
ExSpect 6.4 : an executable specification tool for hierarchical colored Petri Nets
http://alexandria.tue.nl/campusonly/Metis136526.pdf Ten years ago ExSpect became available on the market. Since then a lot of modeling and simulation projects in logistics, workflow and electronic commerce have been performed using ExSpect. In the past ten years the heart of ExSpect, the simulation engine, has never been changed: it still executes models of hierarchical, timed, colored Petri nets with priorities. Over the years new features have been introduced based on user requests. Three extensions dominate the new functionality of ExSpect. The first is ‘ease of use’ in simulating and carrying out quantitative analysis of workflows. The second is to view Message Sequence Charts for electronic commerce applications using ExSpect. The last is the integration of ExSpect and applications; i.e., to use ExSpect to handle the flow of control for other applications
ExSpect 6.4 : an executable specification tool for hierarchical colored Petri Nets
http://alexandria.tue.nl/campusonly/Metis136526.pdf Ten years ago ExSpect became available on the market. Since then a lot of modeling and simulation projects in logistics, workflow and electronic commerce have been performed using ExSpect. In the past ten years the heart of ExSpect, the simulation engine, has never been changed: it still executes models of hierarchical, timed, colored Petri nets with priorities. Over the years new features have been introduced based on user requests. Three extensions dominate the new functionality of ExSpect. The first is ‘ease of use’ in simulating and carrying out quantitative analysis of workflows. The second is to view Message Sequence Charts for electronic commerce applications using ExSpect. The last is the integration of ExSpect and applications; i.e., to use ExSpect to handle the flow of control for other applications
Final screening round of the NELSON lung cancer screening trial: the effect of a 2.5-year screening interval
Contains fulltext :
165636.pdf (Publisher’s version ) (Closed access)In the USA annual lung cancer screening is recommended. However, the optimal screening strategy (eg, screening interval, screening rounds) is unknown. This study provides results of the fourth screening round after a 2.5-year interval in the Dutch-Belgian Lung Cancer Screening trial (NELSON).Europe's largest, sufficiently powered randomised lung cancer screening trial was designed to determine whether low-dose CT screening reduces lung cancer mortality by ?25\% compared with no screening after 10?years of follow-up. The screening arm (n=7915) received screening at baseline, after 1 year, 2 years and 2.5?years. Performance of the NELSON screening strategy in the final fourth round was evaluated. Comparisons were made between lung cancers detected in the first three rounds, in the final round and during the 2.5-year interval.In round 4, 46 cancers were screen-detected and there were 28 interval cancers between the third and fourth screenings. Compared with the second round screening (1-year interval), in round 4 a higher proportion of stage IIIb/IV cancers (17.3\% vs 6.8\%, p=0.02) and higher proportions of squamous-cell, bronchoalveolar and small-cell carcinomas (p=0.001) were detected. Compared with a 2-year interval, the 2.5-year interval showed a higher non-significant stage distribution (stage IIIb/IV 17.3\% vs 5.2\%, p=0.10). Additionally, more interval cancers manifested in the 2.5-year interval than in the intervals of previous rounds (28 vs 5 and 28 vs 19).A 2.5-year interval reduced the effect of screening: the interval cancer rate was higher compared with the 1-year and 2-year intervals, and proportion of advanced disease stage in the final round was higher compared with the previous rounds.ISRCTN63545820
Subsuming the BPM Life Cycle in an Ontological Framework of Designing
Abstract. This paper proposes a framework to represent life-cycle activities performed in business process management (BPM). It is based on the functionbehaviour-structure (FBS) ontology that represents all design entities uniformly, independently of the specific stages in their life cycle. The framework specifies a set of distinct activities that operate on the function, behaviour and structure of a business process, subsuming the different life-cycle stages within a single framework. This provides an explicit description of a number of BPM issues that are inadequately addressed in current life-cycle models. They include design-time analysis, flexibility of tasks and sub-processes, interaction between life-cycle stages, and the use of experience
GoalDAG – ArchiMate Integration
Organizational alignment is an important issue in various interest areas such as Strategy, Business Process Management, Requirements Engineering, and Enterprise Architecture. From IT perspective the most holistic approach on alignment and control is Enterprise Architecture. Enterprise Architecture's eminent standard framework is TOGAF with companion architecture modeling language ArchiMate. Although ArchiMate proposes Motivation Extension to facilitate strategic alignment, this extension does not offer any facility to verify and/or validate the architecture model. Moreover, the Motivation Extension proposes its model elements to be linked to the core elements only through the stakeholder element. This paper proposes an ArchiMate Profile for GoalDAG. GoalDAG is a simple goal model that can be linked to the different model elements seamlessly and enables to validate the existing model. To represent GoalDAG integration with Enterprise Architecture, ArchiMate GoalDAG profile is developed and exemplified through TOGAF's ArchiSurance fictitious case study