Calibration of focusing steps and image rotation of electron microscopes

Reflection electron microscopy (REM) is used to calibrate the focusing steps and rotation of electron microscopes. The calibration of focusing steps is done by the direct measurement of the shift on in-focus positions in the REM micrographs. Rotations between the diffraction patterns and images are calibrated in the usual way. By using the REM geometry, the reflection high energy electron diffraction (RHEED) patterns and REM images have no rotation symmetry, thus eliminating the 180° uncertainty.     

Decision-making in Water Management under Uncertainty

Decision-making in water management requires the delivery of accurate scientific information. However, the task is challenging under the situation where a large amount of uncertainty exists in the available information (e.g., model outputs). This paper investigates the effect of uncertainty on the ranking of options in water management. Different methods for ranking the management options under uncertainty are reviewed and they account for only partial uncertainty information in model outputs. To consider the full uncertainty information, a new ranking procedure is proposed in this paper, which is capable of providing more information to decision makers and at the same time taking their opinions on uncertainty into consideration. The ranking is achieved by conducting pair-wise comparison of management options, on the basis of the risk defined by the probability of obtaining an unacceptable ranking and the mean difference in model outputs in pair-wise comparison. An application example is presented to illustrate the use of the proposed ranking approach. Furthermore, the sensitivity of management option ranking to different ranking methods and to model uncertainty is also investigated.     

Counting of Microspheres in Electrolytes and Parenteral Solutions

The counts of microspheres in 20 testing solutions were determined using 2 Coulter Counters (electrical resistance) and 2 HIAC/Royco (light blockage) particle analysers. The mean cumulative number of microspheres (≥2μm) in unit volume of the solutions determined using the Coulter Counters was higher than those determined by HIAC/Royco particle analysers. The mean cumulative counts obtained by the two Coulter Counters are similar; however, t-test analysis shows significant difference for the counts of 8 different types of solutions. The mean cumulative counts obtained by the two HIAC/Royco Counters varied greatly and t-test analysis showed that 18 out of 20 of the solutions gave significant difference     

Trust-Assisted Handover Approach in Hybrid Wireless Networks

In Next-Generation (NG) hybrid wireless networks, Mobile-Controlled Handover (MCHO) is expected to be employed as the handover control mechanism, in contrast to Network-Controlled Handover (NCHO) used in homogeneous wireless networks. As more independent network operators get involved in providing Internet access, roaming mobile users would have to deal with complex trust relationships between heterogeneous network domains. The state-of-the-art handover approaches just take into account Quality of Service (QoS), but ignore the complexities arising from the coexistence of multiple network operators in the NG networks. The existence of a complex trust relationship between networks may lead to unnecessary handover attempts in service roaming. In this regard, this paper introduces a novel approach of dynamically retrieving network trust information, and using it in MCHO. We show how network trust information can be utilised to obtain a 35% reduction in handover delay, meanwhile retain QoS in a handover. The proposed scheme does not need bulk storage in mobile handsets, and can react to changes to network topology and trust relationships dynamically. Analytical results are provided to demonstrate how roaming mobile users make more intelligent and reliable handover if implementing the proposed handover approach in a multi-operator and multi-technology environment.     

Value‐added products from underutilized fish species

Fish is a rich source of easily digestible protein that also provides polyunsaturated fatty acids, vitamins, and minerals for human nutrition. Nonetheless, a large proportion of total landed fish remains unused due to inherent problems related to unattractive color, flavor, texture, small size, and high fat content. Most of these underutilized fish belong to the abundantly available pelagic species, which are landed as bycatch, and some are unconventional species such as krill. Although some species are used industrially for fish meal manufacture, a need for their conservation and utilization for human consumption has been recognized in order to prevent post‐harvest fishery losses. Recovery of flesh by mechanical deboning and development of value‐added products are probably the most promising approaches. This article discusses various possibilities for product development using mince from low‐cost fishery resources. These include surimi and surimi‐based products, sausages, fermented products, protein concentrates and hydrolysates, extruded products, and biotechnological possibilities. The dual advantages of this approach, namely, finding ways for better utilization of low‐value fish species and providing protein‐rich convenience foods, have been pointed out. However, the key to the success of this approach depends largely on the market strategies utilized.     

An Anticipative Recursively Adjusting Mechanism for parallel file transfer in data grids

Data Grids enable the sharing, selection, and connection of a wide variety of geographically distributed computational and storage resources for content needed by large‐scale data‐intensive applications such as high‐energy physics, bioinformatics, and virtual astrophysical observatories. In Data Grids, co‐allocation architectures were developed to enable parallel downloads of data sets from selected replica servers. As Internet is usually the underlying network of a grid, network bandwidth plays as the main factor affecting file transfers between clients and servers. In this paradigm, there are still some challenges that need to be solved, such as to reduce differences in finish times between selected replica servers, to avoid traffic congestion resulting from transferring the same blocks in different links among servers and clients, and to manage network performance variations among parallel transfers. In this paper, we propose the Anticipative Recursively Adjusting Mechanism (ARAM) scheme to adjust the workloads on selected replica servers and handle unpredictable variations in network performance by those servers. Our algorithm is based on using the finish rates for previously assigned transfers to anticipate the bandwidth status for the next section to adjust workloads, and to reduce file transfer times in grid environments. Our approach is useful in grid environments with unstable network link. It not only reduces idle time wasted waiting for the slowest server, but also decreases file transfer completion times. Copyright © 2010 John Wiley & Sons, Ltd.     

Multiple-Objective Scheduling for the Hierarchical Control of Flexible Manufacturing Systems

This paper presents a hierarchical approach to scheduling flexible manufacturing systems (FMSs) that pursues multiple performance objectives and considers the process flexibility of incorporating alternative process plans and resources for the required operations. The scheduling problem is solved at two levels: the shop level and the manufacturing system level. The shop level controller employs a combined priority index developed in this research to rank shop production orders in meeting multiple scheduling objectives. To overcome dimensional complexity and keep a low level of work-in-process inventory, the shop controller first selects up to three production orders with the highest ranking as candidates and generates all possible release sequences for them, with or without multitasking. These sequences are conveyed to the manufacturing system controller, who then performs detailed scheduling of the machines in the FMS using a fixed priority heuristic for routing parts of multiple types while considering alternative process plans and resources for the operations. The FMS controller provides feedback to the shop controller with a set of suggested detailed schedules and projected order completion times. On receiving these results, the shop controller further evaluates each candidate schedule using a multiple-objective function and selects the best schedule for execution. This allows multiple performance objectives of an FMS to be achieved by the integrated hierarchical scheduling approach.     

Multi-objective stochastic groundwater management of nonuniform,homogeneous aquifers

Like any other resources planning and management, groundwater management is performed in a stochastic environment in which the system itself involves a number of random elements. Consequences as a result of decisions made based on analyses are not certain. This paper presents a management model using the chance-constrained framework which explicitly considers the random nature of aquifer properties. The model enables the derivation of an optimal groundwater management policy that would satisfy required operation performance reliability. Furthermore, the chance-constrained model is extended to the multi-objective optimization framework in which a tradeoff between total water supply pumpage and system performance reliability is explicitly considered. The models are applied to a hypothetical example of a steady, nonuniform, homogeneous confined aquifer.     

Advanced SPICE modeling of large power IGBT modules

An enhanced insulated gate bipolar transistor (IGBT) model based on the Kraus model with new derivations based on an extra parameter accounting for p-i-n injection was developed to allow simulation of both trench and DMOS IGBT structures. Temperature dependence was also implemented in the model. The model was validated against steady-state and transient measurements done on an 800-A 1.7-kV Dynex IGBT module at 25/spl deg/C and 125/spl deg/C. The Spice model has also shown excellent agreement with mixed mode MEDICI simulations. The Spice model also takes into account for the first time the parasitic thyristor effect allowing the dc and dynamic temperature-dependent latchup modeling of power modules as well as their temperature-dependent safe operating area.