A random search approach to the machine loading problem of an FMS

This paper discusses a modelling framework that addresses operational planning, problems of flexible manufacturing systems (FMSs). A generic 0-1 mixed integer programming formulation integrating the part selection and loading problems has been proposed. The constraints considered in the problems are mainly the availability of tool slots and machining time on the machining centres. The above problem is solved using an algorithm based on Simulated Annealing (SA). The potential capability of the approach is demonstrated via a small set of test problems. ©2004 IEEE.published_or_final_versio

Reducing Attack Surface of a Web Application by Open Web Application Security Project Compliance

The attack surface of a system is the amount of application area that is exposed to the adversaries. The overall vulnerability can be reduced by reducing the attack surface of a web application. In this paper, we have considered the web components of two versions of an in-house developed project management web application and the attack surface has been calculated prior and post open web application security project (OWASP) compliance based on a security audit to determine and then compare the security of this Project Management Application. OWASP is an open community to provide free tools and guidelines for application security. It was observed that the attack surface of the software reduced by 45 per cent once it was made OWASP compliant. The vulnerable surface exposed by the code even after OWASP compliance was due to the mandatory access points left in the software to ensure accessibility over a network.Defence Science Journal, 2012, 62(5), pp.324-330, DOI:http://dx.doi.org/10.14429/dsj.62.129

Modified Taguchi-Based Approach for Optimal Distributed Generation Mix in Distribution Networks

In this paper, a new two-stage optimization framework is proposed to determine the optimal-mix integration of dispatchable Distributed Generation (DG), in power distribution networks, in order to maximize various techno-economic and social benefits simultaneously. The proposed framework incorporates some of the newly introduced regulatory policies to facilitate low carbon networks. A modified Taguchi Method (TM), in combination with a node priority list, is proposed to solve the problem in a minimum number of experiments. Nevertheless, the standard TM is computationally fast but has some inherent tendencies of local trapping and usually converges to suboptimal solutions. Therefore, two modifications are suggested. A roulette wheel selection criterion is applied on priority list to select the most promising DG nodes and then modified TM determines the optimal DG sizes at these nodes. The proposed approach is implemented on two standard test distribution systems of 33 and 118 buses. To validate the suggested improvements, various algorithm performance parameters such as convergence characteristic, best and worst fitness values, and standard deviation are compared with existing variants of TM, and improved genetic algorithm. The comparison shows that the suggested corrections significantly improve the robustness and global searching ability of TM, even compared to meta-heuristic methods

Mobile Power Infrastructure Planning and Operational Management for Smart City Applications

The paper presents new strategies and algorithms for future mobile power infrastructure planning and operational management in smart cities. The efforts have been made to develop a resilient Electric Vehicle (EV) infrastructure for smart city applications. The goal of this work is to maximize the profit of utility and EV owners participating in real-time smart city energy market subjected to numerous techno-economic constraints of the EVs and power distribution system. For effective real-time applications, the knowledge of artificial intelligence and internet of things (IoT) are used in the proposed model. In order to validate the proposed model for smart city applications, IEEE 33-bus radial distribution network is adopted as a small city power network. The simulation results of proposed model are found to be encouraging when it is compared with the case in which conventional strategies are used

Optimal accommodation and management of high renewable penetration in distribution systems

The paper presents a new bi-level optimisation framework for optimal accommodation and operational management of wind power generation and battery energy storage system (BESS) simultaneously, aiming to maximise the renewable hosting capacity of distribution networks. A new objective function is suggested comprising of annual energy loss in feeders, reverse power flow into the grid, non-utilised BESS capacities, round-trip conversion losses of BESSs and node voltage deviation subjected to various system security constraints. An artificial-intelligence-based optimal management of BESS is proposed for effective control of high-renewable power generation. Due to the high investment and running costs of BESS, minimum storage capacity has been ensured in planning stage. In order to show the effectiveness of the proposed model, it is implemented on a benchmark test distribution system of 33-bus. Besides, various test cases are investigated and compared, which shows that the proposed optimisation model is promising

Optimal integration and management of solar generation and battery storage system in distribution systems under uncertain environment

The simultaneous placement of solar photovoltaics (SPVs) and battery energy storage systems (BESSs) in distribution systems is a highly complex combinatorial optimization problem. It not only involves siting and sizing but is also embedded with charging and discharging dispatches of BESSs under dynamically varying system states with intermittency of SPVs and operational constraints. This makes the simultaneous allocation a nested problem, where the operational part acts as a constraint for the planning part and adds complexity to the problem. This paper presents a bi-layer optimization strategy to optimally place SPVs and BESSs in the distribution system. A simple and effective operating BESS strategy model is developed to mitigate reverse power flow, enhance load deviation index and absorb variability of load and power generation which are essential features for the faithful exploitation of available renewable energy sources (RESs). In the proposed optimization strategy, the inner layer optimizes the energy management of BESSs for the sizing and siting as suggested by the outer layer. Since the inner layer optimizes each system state separately, the problem search space of GA is significantly reduced. The application results on a benchmark 33-bus test distribution system highlight the importance of the proposed method

Optimal planning of hybrid energy conversion systems for annual energy cost minimization in Indian residential buildings

The increasing interest in renewables has encouraged power system planners to include the concept of hybrid energy systems in modern power industry. Besides, the modern power consumers are becoming more concerned about their energy bills which has led to the concept of hybrid energy management systems (HEMSs) for buildings to monitor, control and optimally manage energy consumptions without any waste. In this study, an optimal planning framework is proposed to determine optimal capacities and sharing of hybrid energy conversion systems (HECS) such as wind turbine, solar photovoltaic, battery energy storage and the utility grid. The objective is to maximize the net present value of the project/system which includes the cost of annual investment, operation and maintenance costs of HEMS expected to have incurred in the planning period. All the costs and parameters are considered in the Indian context, and Genetic Algorithm (GA) is adopted to solve this proposed planning framework. The simulation results obtained are compared with same obtained for conventional houses in India. The comparison shows that the proposed framework effectively reduces the electricity bills while improving its reliability

Implementing collaboration moderator service to support various phases of virtual organisations

This is an Accepted Manuscript of an article published by Taylor & Francis in International Journal of Production Research on Oct 2013, available online: http://www.tandfonline.com/10.1080/00207543.2013.849824Research into moderators, which support collaborative teams by proactively making team members aware of actions or potential problems which may affect them, began in the 1990s, in the context of supporting collaborations during concurrent engineering projects. This paper provides a background to the evolution of moderators and explores their role in supporting virtual organisations. A collaboration moderator (CM) is an evolution of earlier moderators and is capable of behaving differently for different types of users and therefore caters for the varying requirements of individual users depending on the roles they have in the collaborations. This paper describes the architecture and components of a CM from an implementation perspective. Prototype CMs have been developed during the EU-funded SYNERGY project, and two use cases for which the prototype CMs were implemented as a service (a Pre-Creation use case and an Operational use case) are also discussed in this paper

Multi-objective optimal DG allocation in distribution networks using bat algorithm

Paper presented to the 3rd Southern African Solar Energy Conference, South Africa, 11-13 May, 2015.The Distributed Generations (DGs) storage may store energy during solar energy peak and use it during peak demand. Proper allocation of DG storage is essential to extract maximum possible benefits. This paper introduces a Bat Algorithm (BA) for optimal allocation of DGs in radial distribution networks. The problem is formulated to maximize annual energy loss reduction and to maintain a better node voltage profile under a piece-wise linear variable load pattern using a penalty factor approach. The proposed method is applied on the benchmark IEEE 33-bus and 69-bus system available in literature and the results obtained are promising.dc201

Laparoscopic versus open colorectal surgery in the acute setting (LaCeS trial): a multicentre randomized feasibility trial

AbstractBackgroundApproximately 30,000 people per annum undergo major, emergency abdominal, gastrointestinal surgery, of which 36% (~10,800) are carried out for emergency colorectal pathology. Approximately 14% of all patients requiring emergency surgery undergo laparoscopic surgery. AimsThe aims of the LaCeS feasibility trial (Laparoscopic versus Open Colorectal Surgery in the Acute Setting) were to assess the feasibility, safety and acceptability of performing a large-scale definitive phase III randomised controlled trial with a comparison of emergency laparoscopic with open surgery for acute colorectal pathology. MethodsLaCeS was designed as a prospective, multicentre, single blind, parallel group, pragmatic, randomised controlled feasibility trial with an integrated qualitative study. Randomisation was performed centrally with patients being randomised on a 1:1 basis between laparoscopic or open surgery. ResultsA total of 64 patients were recruited across 5 centres. The overall average steady state recruitment rate was 1.2 patients/month. Baseline compliance for clinical and HrQoL data was 99.8% and 93.8% respectively. The conversion rate from laparoscopic to open surgery was 39.4% (95% CI 22.9% – 57.9%). The 30 day post-operative complication rate was 27.3% (95% CI 13.3- 45.5) in the laparoscopic arm and 41.9% (95% CI 24.6 – 60.9) in the open arm. DiscussionThe LaCeS feasibility trial has demonstrated that it is possible to evaluate laparoscopic surgery in the emergency colorectal setting within the context of a randomised controlled trial. LaCeS has demonstrated that it is possible to recruit to a surgical trial in the emergency setting, with good compliance to trial procedures and processes, and overall acceptability by patients and clinicians. The safety data obtained for laparoscopic emergency colorectal surgery indicate an acceptable safety profile, particularly when considering it to that observed in the open arm.Trial Registration ISRCTN15681041 https://doi.org/10.1186/ISRCTN15681041.Funding body: National Institute of Health Research – Research for Patient Benefi