Constraint Propagation in Presence of Arrays

We describe the use of array expressions as constraints, which represents a consequent generalisation of the "element" constraint. Constraint propagation for array constraints is studied theoretically, and for a set of domain reduction rules the local consistency they enforce, arc-consistency, is proved. An efficient algorithm is described that encapsulates the rule set and so inherits the capability to enforce arc-consistency from the rules.Comment: 10 pages. Accepted at the 6th Annual Workshop of the ERCIM Working Group on Constraints, 200

Constraint-Based Qualitative Simulation

We consider qualitative simulation involving a finite set of qualitative relations in presence of complete knowledge about their interrelationship. We show how it can be naturally captured by means of constraints expressed in temporal logic and constraint satisfaction problems. The constraints relate at each stage the 'past' of a simulation with its 'future'. The benefit of this approach is that it readily leads to an implementation based on constraint technology that can be used to generate simulations and to answer queries about them.Comment: 10 pages, to appear at the conference TIME 200

Modified sorting technique to mitigate the collateral mortality of trawled school prawns (Metapenaeus macleayi)

The potential for changes to onboard handling practices in order to improve the fate of juvenile school prawns (Metapenaeus macleayi) discarded during trawling were investigated in two Australian rivers (Clarence and Hunter) by comparing a purpose-built, water-filled sorting tray against a conventional dry tray across various conditions, including the range of typical delays before the start of sorting the catch (2 min vs. 15 min). Juvenile school prawns (n= 5760), caught during 32 and 16 deployments in each river, were caged and sacrificed at four times: immediately (T0), and at 24 (T24), 72 (T72), and 120 (T12 0) hours after having been discarded. In both rivers, most mortalities occurred between T0 and T24 and, after adjusting for control deaths (<12%), were greatest for the 15-min conventional treatment (up to 41% at T120). Mixed-effects logistic models revealed that in addition to the sampling time, method of sorting, and delay in sorting, the weight of the catch, salinity, and percentage cloud cover were significant predictors of mortality. Although trawling caused some mortalities and comparable stress (measured as L -lactate) in all school prawns, use of the water tray lessened the negative impacts of some of the above factors across both the 2-min and 15-min delays in sorting so that the overall discard mortality was reduced by more than a third. When used in conjunction with selective trawls, widespread application of the water tray should help to improve the sustainability of trawling for school prawns

Scanning Acoustic GHz-Microscopy in Microelectronics Failure Analysis

The ongoing trend in microelectronics aims at increasing functionality while reducing the devices footprint. This leads to the currently highly pursued approach of three-dimensional integration of individual devices with e.g. sensors and application specific integrated circuitry resulting in highly integrated and complex systems. By extending the system structure to the third spatial dimension, the aim of chip-to-wafer or wafer-to-wafer bonding techniques is no longer restricted to mechanical integration only. Techniques like adhesive bonding, Cu/Cu thermo-compression bonding or hybrid bonding have also to provide a precise formation of robust and reliable vertical electrical interconnects within the bonding interface. Furthermore, the interaction of Through-Silicon-Via technology (TSV) that enables an efficient 3D-distribution concept with the bonding technologies have to be taken into account. As a consequence, these new technological concepts lead to new defect risks which require novel and adapted inspection methods for assessing quality-related properties and understanding the physical relationship. Today scanning acoustic microscopy (SAM) is already widely used in quality control and failure analysis applications within microelectronics development and manufacturing. The technique is particularly sensitive to material boundaries for the assessment of quality- and reliability- affecting factors like voids and inclusions, cracks, delamination, bonding defects, and many more [1]. Since 3D-integration technologies result in reduced spatial dimensions of the electrical and mechanical interconnects and, thus smaller defects, the demand on the resolution capabilities of potential inspection techniques increases. The successful application of SAM in 3D integration however, requires overcoming limitations in the achievable spatial resolution and the integration of adapted SAM analysis technologies for vertical contacts. The current paper presents the relatively novel approach of applying acoustic microscopy in the GHz-frequency band to increase the achievable lateral resolution and the sensitivity to surface and near-surface features with resolutions in the 1 μm regime. The potential of the GHz-SAM approach will be illustrated describing the inspection of Cu-Cu interfaces in mono-metallic wire bond systems [2] and the detection and propagation-assessment of stress induced voids in thick Al-power lines for high-temperature applications. Using short focal-length transducers GHz-SAM was also applied for the detection of delaminations in sub-surface electrical lines and the detection of cracks in the passivation layer of an RFID chip and the cracks sub-surface propagation. Finally, preliminary results of on-going research addressing the inspection of Through-Silicon-Vias will be presented and discussed

Constraints in Non-Boolean Contexts

In high-level constraint modelling languages, constraints can occur in non-Boolean contexts: implicitly, in the form of partial functions, or more explicitly, in the form of constraints on local variables in non-Boolean expressions. Specifications using these facilities are often more succinct. However, these specifications are typically executed on solvers that only support questions of the form of existentially quantified conjunctions of constraints. We show how we can translate expressions with constraints appearing in non-Boolean contexts into conjunctions of ordinary constraints. The translation is clearly structured into constrained type elimination, local variable lifting and partial function elimination. We explain our approach in the context of the modelling language Zinc. An implementation of it is an integral part of our Zinc compiler

Branch-and-Price Solving in G12

The G12 project is developing a software environment for stating and solving combinatorial problems by mapping a high-level model of the problem to an efficient combination of solving methods. Model annotations are used to control this process. In this paper we explain the mapping to branch-and-price solving. G12 supports the selection of specialised subproblem solvers, the aggregation of identical subproblems, automatic disaggregation when required by search, and the use of specialised branching rules. We demonstrate the benefits of the G12 framework on three examples: a trucking problem, cutting stock, and two-dimensional bin packing

Magneto-optic dynamics in a ferromagnetic nematic liquid crystal

We investigate dynamic magneto-optic effects in a ferromagnetic nematic liquid crystal experimentally and theoretically. Experimentally we measure the magnetization and the phase difference of the transmitted light when an external magnetic field is applied. As a model we study the coupled dynamics of the magnetization, M, and the director field, n, associated with the liquid crystalline orientational order. We demonstrate that the experimentally studied macroscopic dynamic behavior reveals the importance of a dynamic cross-coupling between M and n. The experimental data are used to extract the value of the dissipative cross-coupling coefficient. We also make concrete predictions about how reversible cross-coupling terms between the magnetization and the director could be detected experimentally by measurements of the transmitted light intensity as well as by analyzing the azimuthal angle of the magnetization and the director out of the plane spanned by the anchoring axis and the external magnetic field. We derive the eigenmodes of the coupled system and study their relaxation rates. We show that in the usual experimental set-up used for measuring the relaxation rates of the splay-bend or twist-bend eigenmodes of a nematic liquid crystal one expects for a ferromagnetic nematic liquid crystal a mixture of at least two eigenmodes.Comment: 20 pages, 23 figures, 42 reference