Applications of Level 2 BLAS in the NAG library

We describe work done to improve the performance of NAG Library routines for nonlinear equations and nonlinear least squares problems on vector-processing machines. Calls to the Level 2 BLAS routines for matrix-vector operations were introduced wherever possible, so that further efforts to tune the code could be concentrated within the Level 2 BLAS, and advantage can be taken of optimized implementations of the Level 2 BLAS when they become available. Performance measurements from a CRAY-1S, an AMDAHL VP1100, and a CDC CYBER 205 are presented to illustrate the effectiveness of this strategy.     

Space charge analysis in doped zinc phthalocyanine thin films

We present an improved method for the determination of the space charge density in organic semiconductors used as active layers in Schottky barriers. These measurements provide a powerful tool for the interpretation of basic properties such as the rectifying effect, doping process and carrier trapping mechanisms of films together with a way to assess the potential for sensor applications. Metal/molecular semiconductor Schottky junctions were prepared on zinc phthalocyanine layers doped by a controlled exposure to the ambient air. The organic material is deposited on aluminium or heavily doped silicon substrates, in order to make a Schottky barrier (film thickness around 1 μm). An ohmic contact is obtained by a gold deposition on the strongly doped side of the molecular material. We have investigated the current-voltage and capacitance-voltage characteristics. The results are interpreted in terms of a space charge region at the interface with the substrate, followed by an extended semi-insulating layer.The contribution of these two regions to the total impedance is analyzed in well improved conditions of measurements.     

Standing up to the big squeeze

Consumer confidence is at its lowest ebb since 1980. Economic growth is at a standstill & unemployment & inflation are both rising. Here's a front-line report from more than three dozen operators who are fending off the recession's dual pressures of slow sales & rising costs. They are using discount pricing, partnering with vendors, setting pay for performance standards & a variety of other recession-beating practices.     

Psychometric Evaluation of the EMO and the SUS in the Context of a Large-Sample Unmoderated Usability Study

This article describes the psychometric properties of the Emotional Metric Outcomes (EMO) questionnaire and the System Usability Scale (SUS) using data collected as part of a large-sample unmoderated usability study (n = 471). The EMO is a concise multifactor standardized questionnaire that provides an assessment of transaction-driven personal and relationship emotional outcomes, both positive and negative. The SUS is a well-known standardized usability questionnaire designed to assess perceived usability. In previous research, psychometric evaluation using data from a series of online surveys showed that the EMO and its component scales had high reliability and concurrent validity with loyalty and overall experience metrics but did not find the expected four-factor structure. Previous structural analyses of the SUS have had mixed results. Analysis of the EMO data from the usability study revealed the expected four-factor structure. The factor structure of the SUS appeared to be driven by item tone. The estimated reliability of the SUS (.90) was consistent with previous estimates. The EMO and its subscales were also quite reliable, with the estimates of reliability for the various EMO scales ranging from .86 to .96. Regression analysis using SUS, EMO, and Effort as predictors revealed different key drivers for the outcome metrics of Satisfaction and Likelihood-to-Recommend. The key recommendations are to include the EMO as part of the battery of poststudy standardized questionnaires, along with the SUS (or similar questionnaire), but to be cautious in reporting SUS subscales such as Usable and Learnable.     

Molecularly imprinted polymer beads: suspension polymerization using a liquid perfluorocarbon as the dispersing phase

A suspension polymerization technique suitable for molecular imprinting is described, based on the use of a liquid perfluorocarbon as the dispersing phase. This dispersant does not interfere with the interactions between functional monomers and print molecules required for the recognition process during molecular imprinting. The method produces polymer beads, with almost quantitative yield, which can be used after only a simple washing step. An acrylate polymer with perfluorocarbon and poly(oxyethylene) ester groups was used to stabilize an emulsion of functional monomer, cross-linker, print molecule, initiator, and porogenic solvent in perfluoro(methylcyclohexane). Initiation of polymerization by UV irradiation resulted in polymer beads. The average bead size could be controlled between about 50 and 5 μm by varying the amount of stabilizing polymer. SEM of the beads indicated spherical particles with morphology typical of beads made by suspension polymerization. The technique was applicable to a range of conditions typically used for molecular imprinting. A detailed chromatographic study of the polymer beads confirmed that α values and resolution factors were similar to those achieved with traditional ground and sieved imprinted polymers. Small (5 μm) beaded packings gave low back pressure and rapid diffusion, giving good separation even at high flow rates.     

Recalling Spatial Information as a Component of Recently and Remotely Acquired Episodic or Semantic Memories: An fMRI Study.

Activations produced by the recall of episodic and semantic memories differing in spatial content and age were examined. Recall of recent episodic memories with differing spatial content activated the medial temporal lobes and the retrosplenial-posterior cingulate cortex-precuneus complex more than recall of recent semantic memories with similarly differing spatial content. Some of these differences related to the amount of spatial information recalled because spatially richer recent memories, regardless of whether they were episodic or semantic, activated the right posterior parahippocampal cortex, precuneus, and posterior parietal cortex more. This spatial effect was found to be independent of memory age for semantic memories, although some episodic-semantic memory differences, including one in the left hippocampus, were not age independent. Episodic-semantic memory recall activation differences are therefore probably a function of the amount recalled, memory age, and what is recalled, particularly with respect to spatial information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sandtray therapy with a 24-year-old woman in the residual phase of schizophrenia.

Sandtray therapy is a clinical tool for helping a client express and understand his or her unconscious dynamics. It utilizes a sandtray and anywhere from a few hundred to a few thousand figurines in the room for the client to select from. These figurines cover a wide range of people, situations, and objects, from the most ordinary to the mythical. The client makes a story in the sand, which the client and therapist then discuss. It is standard therapeutic wisdom that one should not use techniques involving fantasy with psychotic clients since it is typically too hard for both them and the clinician to contain those fantasies in a healthy manner. Although this is very often true, the authors offer an example of how they were able to use sandtray to great therapeutic advantage with a schizophrenic client in the residual phase of schizophrenia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A 200 mW, 1 Msample/s, 16-b pipelined A/D converter with on-chip32-b microcontroller

This paper describes the design and implementation of a fully monolithic 16-b, 1 Msample/s, low-power A/D converter (ADC). An on-chip 32-b custom microcontroller calibrates and corrects the pipeline linearity to within 0.75 LSB integral nonlinearity (INL) and 0.6 LSB differential nonlinearity (DNL). High speed and low power are achieved using a pipelined architecture. Errors resulting from capacitor mismatches, finite op-amp open loop gain, charge injection and comparator offset are removed through self-calibration. Coefficients determined during calibration are stored on chip, digitally correcting the pipeline ADC in real time during normal conversion, Full-scale errors are removed through self-calibration and an-chip multiplication. Linearity errors due to capacitor voltage coefficients are reduced using a curve fit algorithm and on-chip ROM. Digital cross-talk errors resulting from the microcontroller running at a rate of ten times the analog sampling rate have prevented implementations of fully monolithic converters of this performance class in the past. Mismatches in cross-talk due to different digital timing between calibration and correction lead to linearity errors at critical correction points. Experimental analysis and circuit techniques which overcome these problems are presented     

Composition, coagulation properties, and cheesemaking potential of milk from cows undergoing extended lactations in a pasture-based dairying system

Extending the lactation length of dairy cows beyond the traditional 10 mo toward lactations of up to 22 mo has attracted interest in the pasture-based seasonal dairying systems of Australia and New Zealand as a way of alleviating the need for cows to conceive during peak lactation, such as is required to maintain seasonally concentrated calving systems. Lactation lengths longer than 10 mo instead provide cows with more time to cycle and conceive after parturition and may therefore be more suitable systems for high-producing Holstein-Friesian cows. Before recommending such systems there is a need to evaluate the effects of long lactations on the suitability of milk for manufacture of high-quality dairy products. In the current experiment, the composition of milk from cows entering the second half of a 22-mo lactation was examined in detail and compared with that from cows undergoing a traditional 10-mo lactation. On 2 occasions, coagulation properties were measured using low amplitude strain oscillation rheometry, and Cheddar cheese was made in 250-L pilot-scale vats. Results showed that milk from extended lactations had higher concentrations of fat and protein than cows undergoing 10-mo lactations under similar management conditions and at the same time of year. The ratio of casein to true protein was not affected by lactation length and neither were the proportions of individual caseins. The increase in milk solids during extended lactations translated into a more rapid rate of coagulation and ultimately a firmer curd on one of the two occasions. Milk from extended lactations yielded more cheese per 100 kg of milk, and there were few differences in the composition or organoleptic properties of the cheese. These data are the first to show that pasture-based dairy industries could embrace the use of extended lactations without compromising the core business of producing high-quality dairy products.