Instance generators and test suites for the multiobjective quadratic assignment problem

We describe, and make publicly available, two problem instance generators for a multiobjective version of the well-known quadratic assignment problem (QAP). The generators allow a number of instance parameters to be set, including those controlling epistasis and inter-objective correlations. Based on these generators, several initial test suites are provided and described. For each test instance we measure some global properties and, for the smallest ones, make some initial observations of the Pareto optimal sets/fronts. Our purpose in providing these tools is to facilitate the ongoing study of problem structure in multiobjective (combinatorial) optimization, and its effects on search landscape and algorithm performance.

Examining random number generators used in stochastic iteration algorithms

This paper investigates random number generators in stochastic iteration algorithms that require infinite uniform sequences. We take a simple model of the general transport equation and solve it with the application of a linear congruential generator, the Mersenne twister, the mother-of-all generators, and a true random number generator based on quantum effects. With this simple model we show that for reasonably contractive operators the theoretically not infinite-uniform sequences perform also well. Finally, we demonstrate the power of stochastic iteration for the solution of the light transport problem.

A note on an integration by parts formula for the generators of uniform translations on configuration space

An integration by parts formula is derived for the first order differential operator corresponding to the action of translations on the space of locally finite simple configurations of infinitely many points on Rd. As reference measures, tempered grand canonical Gibbs measures are considered corresponding to a non-constant non-smooth intensity (one-body potential) and translation invariant potentials fulfilling the usual conditions. It is proven that such Gibbs measures fulfill the intuitive integration by parts formula if and only if the action of the translation is not broken for this particular measure. The latter is automatically fulfilled in the high temperature and low intensity regime.

Using standby generators in support of an electricity network: logistics and experience

Electricity load shifting is becoming a big topic in the world of ‘green’ retail. Marks & Spencer (M&S) aim to become the world’s most sustainable retailer (1) and part of that commitment means contributing to the future electricity network. While intelligent operation of fridges and Heating, Ventilation and Air Conditioning (HVAC) systems are a wide area of research, standby generators should be considered too, as they are the most widely adopted form of distributed generation. In this paper, the experience of using standby generators in Northern Ireland to support the grid is shared and the logistics of future projects are discussed. Interactions with maintenance schedules, electricity costs, grid code, staffing and store opening times are discussed as well as the financial implications associated with running generators for grid support.

Financial implications for companies running standby generators in support of a smart grid

Integrating renewable energy into built environments requires additional attention to the balancing of supply and demand due to their intermittent nature. Demand Side Response (DSR) has the potential to make money for organisations as well as support the System Operator as the generation mix changes. There is an opportunity to increase the use of existing technologies in order to manage demand. Company-owned standby generators are a rarely used resource; their maintenance schedule often accounts for a majority of their running hours. DSR encompasses a range of technologies and organisations; Sustainability First (2012) suggest that the System Operator (SO), energy supply companies, Distribution Network Operators (DNOs), Aggregators and Customers all stand to benefit from DSR. It is therefore important to consider impact of DSR measures to each of these stakeholders. This paper assesses the financial implications of organisations using existing standby generation equipment for DSR in order to avoid peak electricity charges. It concludes that under the current GB electricity pricing structure, there are several regions where running diesel generators at peak times is financially beneficial to organisations. Issues such as fuel costs, Carbon Reduction Commitment (CRC) charges, maintenance costs and electricity prices are discussed.

Operator, organizational, direct support, and general support maintenance manual : motor generator, power supply generator, 60 kw, 120/208, 240/416 volt, 3-phase, 4 wire service, 400 hertz, DC component output, 28 volt, 10 amp, motor input AC, 416 volt, 3-phase, 60 hertz, portable skid mounted (General Dynamics Corp. model 14105008), FSN 6125-917-2244.

"June 1971."

Operator and organizational maintenance manual : generator set, diesel engine, precise power, 100 kw, AC, 120/208V, 240/416V, 3 phase, 60 cycle, at 1800 rpm, 83.3 kw, 120/208V, 240/416V, 3 phase, 50 cycle at 1500 rpm, skid mounted ....

"April 1961."

Operator and organizational maintenance manual : generator set, gas turbine engine : 45 KW, AC, 120/208, 240/416V, 3 phase, 4 wire : skid mounted, winterized, (Airesearch model GTGE 70-6-1), FSN 6115-075-1639.

"24 November 1971."

Direct support and general support maintenance manual : generator set, gas turbine engine, 45 KW, AC, 120/208, 240/416 V, 3 phase, 4 wire, skid mounted, winterized (Airesearch model GTGE 70-6-1), FSN 6115-075-1639.

Includes index.

Operator, organizational, intermediate (field) (direct support and general support) and depot maintenance manual : generator set, gasoline engine driven, skid mounted, tubular frame, 10 KW, AC, 120/208 V, 3 phase and 120/240 V, single phase - less engine : DoD model MEP-018A ....

"June 1977."

Operator, organizational, direct support, and general support maintenance manual : generator set, gasoline engine driven, skid mounted, tubular frame, 3 kw, 3 phase, AC, 120/208 and 120/240 volts, 28 V, DC (less engine) : DOD model MEP-016A ... hertz 60 ... NSN 6115-00-017-8237 ....

"August 1976."

Direct and general support maintenance repair parts and special tools lists (including depot maintenance repair parts and special tools) : generator set, DED, wheel mtd, liquid cooled, 15KW, 400 HZ, AC, 3 phase, 4 wire,120/208 V, non-winterized, special purpose mdl SP-HF-15, w/Hercules engine D198ERX28, FSN 6115-089-5099.

Includes index.

Organizational, intermediate (field), direct support and general support, maintenance repair parts and special tools list (including depot maintenance repair parts and special tools) : generator set, gasoline engine : air cooled, 5 KW, AC, 120/240 V, single phase, 120/208V 3 phase skid mounted, tubular frame (less engine) military design : DoD model MEP-017A, MEP-022A ... 6115-00-017-8241.

"1 May 1986."