Managing Congestion in Vehicular Networks Using Tabu Search

© 2018, Springer Nature Switzerland AG. In this era of communication, exponentially growing networks bring a lot of challenges to address for smoother network functionalities. Among them is efficiency in handling packet traffic to avoid and control congestion. A particular case is applicable to Vehicular Ad-hoc Networks, which are known with unbalanced resource utilisation, communication overheads, high transmission delay and least transmission capacity. This paper aims to minimise the delay and jitter for enhancing the Quality of Service (QoS) in Vehicular Adhoc Networks (VANET) using tabu search algorithm with multi-channel allocation capability. We proposed a scheme that prioritises each message considering the basis of message type or its substances, such as crisis, reference point, and administration oriented etc., and uses tabu search for scheduling the transmission of queued messages in order to enhance the efficiency, security, and durability of VANET. A comprehensive simulation is conducted to validate the proposed scheme and to evaluate the performances in comparison with other state-of-the-art approaches

Optimizing emergency preparedness and resource utilization in mass-casualty incidents

This paper presents a response model for the aftermath of a Mass-Casualty Incident (MCI) that can be used to provide operational guidance for regional emergency planning as well as to evaluate strategic preparedness plans. A mixed integer programming (MIP) formulation is proposed for the combined ambulance dispatching, patient-to-hospital assignment, and treatment ordering problem. T he goal is to allocate effectively the limited resources during the response so as to improve patient outcomes, while the objectives are to minimize the overall response time and the total flow time required to treat all patients, in a hierarchical fashion. The model is solved via exact and MIP-based heuristic solution methods. The applicability of the model and the performance of the new methods are challenged on realistic MCI scenarios. We consider the hypothetical case of a terror attack at the New York Stock Exchange in Lower Manhattan with up to 150 trauma patients. We quantify the impact of capacity-based bottlenecks for both ambulances and available hospital beds. We also explore the trade-off between accessing remote hospitals for demand smoothing versus reduced ambulance transportation times

Modeling and solution for the ship stowage planning problem of coils in the steel industry

This is the peer reviewed version of the following article: TANG, L. ...et al., 2015. Modeling and solution for the ship stowage planning problem of coils in the steel industry. Naval Research Logistics, 62(7), pp. 564-581., which has been published in final form at http://dx.doi.org/10.1002/nav.21664. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.We consider a ship stowage planning problem where steel coils with known destination ports are to be loaded onto a ship. The coils are to be stowed on the ship in rows. Due to their heavy weight and cylindrical shape, coils can be stowed in at most two levels. Different from stowage problems in previous studies, in this problem there are no fixed positions on the ship for the coils due to their different sizes. At a destination port, if a coil to be unloaded is not at a top position, those blocking it need to be shuffled. In addition, the stability of ship has to be maintained after unloading at each destination port. The objective for the stowage planning problem is to minimize a combination of ship instability throughout the entire voyage, the shuffles needed for unloading at the destination ports, and the dispersion of coils to be unloaded at the same destination port. We formulate the problem as a novel mixed integer linear programming model. Several valid inequalities are derived to help reducing solution time. A tabu search (TS) algorithm is developed for the problem with the initial solution generated using a construction heuristic. To evaluate the proposed TS algorithm, numerical experiments are carried out on problem instances of three different scales by comparing it with a model-based decomposition heuristic, the classic TS algorithm, the particle swarm optimization algorithm, and the manual method used in practice. The results show that for small problems, the proposed algorithm can generate optimal solutions. For medium and large practical problems, the proposed algorithm outperforms other methods

A lexicographical dynamic flow model for relief operations

Emergency management is a highly relevant area of interest in operations research. Currently the area is undergoing widespread development. Furthermore, recent disasters have highlighted the importance of disaster management, in order to alleviate the suffering of vulnerable people and save lives. In this context, the problem of designing plans for the distribution of humanitarian aid according to the preferences of the decision maker is crucial. In this paper, a lexicographical dynamic flow model to solve this problem is presented, extending a previously introduced static flow model. The new model is validated in a realistic case study and a computational study is performed to compare both models, showing how they can be coordinated to improve their overall performance

Integration of fuzzy linear optimization and scenario analysis in network flow problems: disaster response perspective

peer reviewedIn this paper, we address the problem of transporting vital commodities and emergency personnel during the response stage of a disaster relief operation by integrating fuzzy linear optimization and the principles of scenario analysis. We treat this transportation system as a probabilistic multi-commodity multi-modal network flow problem and first develop a fuzzy model that allows the satisfaction of demand requirements through different supply nodes over a fuzzy network. Since the available information in case of disasters is generally vague and imprecise about the values of model parameters, fuzzy linear optimization is employed to deal with this uncertainty and to generate different scenarios depending upon the preferences of the decision maker. Then these scenarios are handled within the framework of the scenario analysis by defining a scenario as a joint realization of the uncertain parameters. Here, scenario analysis method can be considered as a search for a robust solution that guarantees the maximum satisfaction of demands with the minimum transportation cost

EARLY DETECTION OF MAINTAINABILITY ISSUES IN MEP SYSTEMS USING BIM

The terms maintainability and maintenance are interrelated and often perceived to be difficult to distinguish from each other. Maintainability refers to the measures and actions taken during the design phase in order to assure that the building components and the system to which it belongs can be easily maintained at minimum downtime and cost. On the other hand, maintenance refers to the measures and action taken during the operation phase in order to keep the components at the desired operational condition. The variance between designers’ and facility managers’ priorities concerning maintainability creates a gap between the design and operation phases. Maintainability is not often considered in design nor is it a priority for designers. Designers consider equipment access to be one of the least important factors related to maintenance. However, design-related maintainability issues such as equipment access problems make maintenance activities impractical if not impossible in facility operation, and increase the life cycle costs of facilities. These issues can be detected in the design phase if an appropriate tool is available, and can prevent maintenance-related problems in the operation phase. This research aims to bridge the gap between design and facility management by developing and deploying a BIM tool that brings a facility management perspective into design, and allows designers to inject maintainability considerations into the design phase. In this study, the building and construction codes and standards adopted and published by the local governments of the United States were investigated in order to identify maintainability standards related to geometric design and parametric information of building components. Parametric rule sets related to maintainability were established according to the codes and standards. From the “equipment access” perspective, a maintainability checking algorithm that can be easily customized for any building component and its rule sets was developed. In order to demonstrate the operation of the algorithm in 3D design view, the algorithm was customized for a particular piece of equipment, codded in C# programing language, and implemented as an add-in called “Maintainability Checker” to the most commonly used BIM software: Revit. A video clip of the demonstration was embedded into a questionnaire, and the questionnaire was administrated to designers and facility managers in order to validate the potential benefits of “Maintainability Checker”. A comparative analysis of designers’ and facility managers’ opinions towards maintainability and “Maintainability Checker” was conducted using SPSS. The survey results indicate that the gap between the design and post-construction phases does exist. However, the survey results also indicate that “Maintainability Checker” can bridge the gap by allowing designers to produce a better design that improves equipment maintenance access and workplace safety, facilitates the cleaning and repair of building components, reduces the number of reworks, improves the efficiency of the commissioning process, and reduces the time spent on maintenance activities, all without increasing the workload of designers. The construction industry should consider an automated maintainability check to be an essential part of the design process, create/adopt design for maintainability standards for every building component that can possibly be in a structure, and use them within BIM tools.Ph.D. in Civil Engineering, May 201

APPLICATION FOR CONSTRUCTION SITE MONITORING WITH MOBILE DEVICES

In this study, information and communication needs are identified relative to construction site operations. Construction Site Monitor (CSM), a hybrid mobile application is created that provides both formal and informal schedule information exchange between project participants with relevant visual attachments. It can be run on iPads, iPhones and Android phones. It has been developed by using Bizness and Wufoo platforms. It is easy to use, provides timely access to schedule/progress information, functions efficiently, hence minimizing costly and time consuming claims and disputes, and finally reliable accurate information compared to traditional paper-based methods. A limited survey of practitioners confirmed that all these benefits are likely to occur if CSM is deployed. The construction industry is behind in adopting information and communication technologies (ICT) as other industries do; the construction industry should pay attention to applications like CSM in order to improve productivity.M.S. in Civil Engineering, December 201

A two-stage stochastic programming framework for transportation planning in disaster response

This study proposes a two-stage stochastic programming model to plan the transportation of vital first-aid commodities to disaster-affected areas during emergency response. A multi-commodity multi-modal network flow formulation is developed to describe the flow of material over an urban transportation network. Since it is difficult to predict the timing and magnitude of any disaster and its impact on the urban system, resource mobilization is treated in a random manner, and the resource requirements are represented as random variables. Furthermore, uncertainty arising from the vulnerability of the transportation system leads to random arc capacities and supply amounts. Randomness is represented by a finite sample of scenarios for capacity, supply and demand triplet. The two stages are defined with respect to information asymmetry which discloses uncertainty during the progress of the response. The approach is validated by quantifying the expected value of perfect and stochastic information in problem instances generated out of actual data