Adjustment Task Research Articles

Fixating picture boundaries does not eliminate boundary extension: Implications for scene representation

Observers frequently remember seeing more of a scene than was shown (boundary extension). Does this reflect a lack of eye fixations to the boundary region? Single-object photographs were presented for 14-15 s each. Main objects were either whole or slightly cropped by one boundary, creating a salient marker of boundary placement. All participants expected a memory test, but only half were informed that boundary memory would be tested. Participants in both conditions made multiple fixations to the boundary region and the cropped region during study. Demonstrating the importance of these regions, test-informed participants fixated them sooner, longer, and more frequently. Boundary ratings (Experiment 1) and border adjustment tasks (Experiments 2-4) revealed boundary extension in both conditions. The error was reduced, but not eliminated, in the test-informed condition. Surprisingly, test knowledge and multiple fixations to the salient cropped region, during study and at test, were insufficient to overcome boundary extension on the cropped side. Results are discussed within a traditional visual-centric framework versus a multisource model of scene perception.

Distinct mechanisms control contrast adaptation over different timescales

Changes to the visual environment can happen at many timescales, from very transient to semi-permanent. To adapt optimally, the visual system also adjusts at different timescales, with longer-lasting environmental changes producing longer-lasting effects, but how the visual system adapts in this way remains unknown. Here, we show that contrast adaptation-the most-studied form of visual adaptation-has multiple controllers, each operating over a different time scale. In a series of experiments, subjects completed either a contrast matching, contrast detection, or tilt adjustment task, while adapting to contrast at one orientation. Following a relatively longer period (5 min) of adaptation to high contrast, subjects were "deadapted" for a shorter period (e.g., 40 s) to a lower contrast. Deadaptation eliminated perceptual aftereffects of adaptation, but continued testing in a neutral environment revealed their striking recovery. These results suggest the following account: Adaptation was controlled by at least two mechanisms, with initial adaptation affecting a longer-term one and deadaptation affecting a shorter-term one in the opposite direction. Immediately following deadaptation, the effects of the two mechanisms cancelled each other, but the short-term effects rapidly decayed, revealing ongoing longer-term adaptation. A single controlling mechanism cannot account for the observed recovery of effects, since once deadaptation cancels the initial longer-term adaptation, no trace of it remains. Combined with previous results at very long adaptation durations, the present results suggest that contrast adaptation is possibly controlled by a continuum of mechanisms acting over a large range of timescales.

Quantitative analysis of locomotor defects in neonatal mice lacking proprioceptive feedback

Proprioceptive feedback derived from specialized receptors in skeletal muscle is critical in forming an accurate map of limb position in space, and is used by the central nervous system to plan future movements and to determine accuracy of executed movements. Knockout mouse strains for genes expressed by proprioceptive sensory neurons have been generated that result in generalized motor deficits, but these deficits have not been quantitatively characterized. Here we characterize a conditional knockout mouse model wherein proprioceptive sensory neuron synaptic transmission has been blocked by selective ablation of munc18-1, a synaptic vesicle associated protein required for fusion of synaptic vesicles with the plasma membrane. Proprioceptive munc18-1 conditional mutants are impaired in surface righting – a dynamic postural adjustment task – and display several specific deficits in pivoting, an early locomotor behavior. Before the emergence of forward locomotion during postnatal development, animals explore their surroundings through pivoting, or rotating the upper torso around the relatively immobile base of the hind limbs. 3-D kinematic analysis was used to quantitatively describe this pivoting behavior at postnatal days 5 and 8 in control and munc18-1 conditional mutants. Mutant animals also pivot, but demonstrate alterations in movement strategy and in postural placement of the forelimbs during pivoting when compared to controls. In addition, brief forelimb stepping movements associated with pivoting are altered in mutant animals. Step duration and step height are increased in mutant animals. These results underscore the importance of proprioceptive feedback even at early stages in postnatal development.

User Preferences in Office Lighting: A Case Study Comparing LED and T5 Lighting

Lighting quality parameters were studied in an office lighting setting for three different luminaire types: 1) square LED panel luminaire (Sq_LED); 2) round LED downlight luminaire (Ro_LED); and 3) rectangular recessed T5 fluorescent lamp luminaire (Re_T5). The lighting conditions were evaluated with subjective assessments and horizontal desktop illuminance measurement in the middle of the task area. Re_T5 lighting was compared to Sq_LED lighting at 300, 600 and 1000 lx. Ro_LED lighting was studied at three different color temperatures: 3000, 4500 and 6000 K. Subjects responded to all nine conditions using identical questionnaires, which contained questions regarding glare, reading task ease, detail distinction from the wall, color naturalness and pleasantness, illuminance level sufficiency and pleasantness, general pleasantness of the lighting, naturalness of the shadows, and the appearance of the luminaires. Subjects also set three lighting conditions: 1) minimum illuminance for brief duration office work using Re_T5 lighting; 2) optimal illuminance for long-time office work using Re_T5 lighting; and 3) optimal illuminance and color temperature using Ro_LED lighting. The illuminance in the test room was preset at 300 lx before a subject entered the room and started these adjustment. The illuminance adjustment ranges were 0-1142 lx for the Re_T5 lighting and 0-738 lx for the Ro_LED lighting. In the CCT adjustment task CCT was preset to 3000, 4500, or 6000 K.Subjects evaluated 600 lx to be equally pleasant to 1000 lx and the reading task was evaluated to be equally easy at these two illuminance levels. However, 1000 lx caused slightly more glare. 300 lx was considered to be less pleasant and the reading and detail distinction from the wall was considered to be more difficult at 300 lx than at higher illuminance levels. At 600 lx the amount of light was considered to be more optimal than at 300 or 1000 lx. There were no significant differences in the user answers between the Re_T5 and Sq_LED lightings at equal illuminance levels. The Ro_LED lighting was considered less pleasant at 6000 K than at 3000 or 4500 K. However, CCT did not have a statistically significant effect on user answers to other questions. When the users adjusted illuminance the overall average preferred illuminance was 648 lx for Re_T5 lighting and 517 lx for the LED lighting; there were large variations in the preferred illuminances between subjects. The Re_T5 lighting had larger illuminance adjustment range than the Ro_LED lighting, which may have affected the preferred settings. The overall mean preferred CCT of the Ro_LED lighting was 4150 K. There were signs that preset CCT affected the user set CCT.

Design of Electronic Medical Record User Interfaces: A Matrix‐Based Method for Improving Usability

This study examines a new approach of using the Design Structure Matrix (DSM) modeling technique to improve the design of Electronic Medical Record (EMR) user interfaces. The usability of an EMR medication dosage calculator used for placing orders in an academic hospital setting was investigated. The proposed method captures and analyzes the interactions between user interface elements of the EMR system and groups elements based on information exchange, spatial adjacency, and similarity to improve screen density and time-on-task. Medication dose adjustment task time was recorded for the existing and new designs using a cognitive simulation model that predicts user performance. We estimate that the design improvement could reduce time-on-task by saving an average of 21 hours of hospital physicians' time over the course of a month. The study suggests that the application of DSM can improve the usability of an EMR user interface.

Regionalizing Immigration, Health and Inequality: Iraqi Refugees in Australia

Humanitarian immigrants and refugees face multiple adjustment tasks and post-settlement support services concentrated in metropolitan areas play an important role. As part of an ongoing commitment, the Australian Government has increasingly supported resettlement in rural and regional areas of the country. Drawing on the experience of Iraqi migrants in Victoria, Australia, we examine some of the conditions that characterize regional resettlement and raise key questions for public health policy. Structural vulnerabilities and discriminations impact upon physical, mental and social wellbeing, leading to further exclusion, with negative long-term implications. The discussion throws light on the issues that migrants and refugees may encounter in other parts within Australia, but are also germane in many countries and highlight the resulting complexity for policy-making.

Heuristic finite-impulse-response filter design for cascaded modulators with finite amplifier gain

This study addresses a new digital calibration filter design for cascaded ΣΔ modulators with finite amplifier gain. A recent approach based on the H-infinity loop shaping method to this problem has the merit of obviating the use of an estimation or adaptive digital correction scheme, which thus reduces the complexity of circuit implementation. For the approach to be successful, it is critical to find an appropriate weighting function so as to make the gain responses of the uncertain noise transfer function (NTF) in a proper shape for improving signal-to-noise ratio (SNR). However, the search of such a weighting function is difficult in general. Moreover, the introduced weighting function increases filter order and hence circuit complexity. To circumvent this difficulty and the inherited drawbacks, this study presents a new noise shaping method for the problem. Considering that it is hard to decide the optimal shape of the uncertain NTF a priori, the authors propose a dual-band design to achieve the shape adjustment task. In particular, the range of lower frequency band is determined by SNR performance evaluation rather than being arbitrarily given a priori. This step is crucial and increases the chance of finding a better filter.

Investigating the use of an adjustment task to set preferred colour of ambient illumination

AbstractAn experiment was carried out to examine the method of adjustment when determining user preferences for the colour appearance of ambient lighting. A booth was lit using luminaires containing an array of white and coloured light emitting diodes (LEDs), allowing continuous variation of correlated colour temperature (CCT) between 2736 and 4014 K. It was predicted that the preferred CCT would be influenced by the available stimulus range, the anchor (initial setting before adjustment), adaptation time before onset of adjustment action and type of control dial. Preference was estimated for three different CCT stimulus ranges within the available range. All three ranges led to significantly different results for preferred CCT: 3288, 3490 and 3671 K. The experimental results confirmed that stimulus range, anchor and adaptation time have significant effect on the preferred CCT determined using the adjustment task, and thus, the importance of considering and reporting this information in studies that employ the method of adjustment. © 2011 Wiley Periodicals, Inc. Col Res Appl, 2013

Assessing Drivers Ability to Carry Out Headway Advice in Motorway Car Driving

In order to improve throughput on motorways, a headway advisory system is being developed. This system could enable drivers to choose their headway differently by providing in-vehicle advice. How well are drivers able to follow a time or a distance headway advice and what effect has vehicle speed and advised headway on their ability? To test this, a group of 20 participants completed nine headway adjustment tasks in a driving simulator experiment. Half of the participants received a time headway advice and half received a distance headway advice. The absolute difference between the advised and the chosen headway acted as a performance measure. In the experiment no performance difference could be found between the driver’s carrying out target headway and those carrying out distance headway advice. Furthermore increasing vehicle speed significantly reduced the driver’s ability to carry out headway advice. This effect was not found for target headway. High inter-driver difference in headway estimation led to high standard deviations in estimation error. Apart from reducing the average estimation error, the support system under development should also focus on reducing the variance in chosen headways.

Efecto de un entrenamiento observacional con descripciones en la transferencia extradimensional.

A research study was carried out to evaluate the effect of an observational training with and without descriptions on an extradimensional transfer test. Two domains were used, one for training and other for testing counterbalancing their order of presentation. Second-order matching-to-sample arrays were built using paintings as instances considering one of two domains: by style (how the painting is represented) or by theme (what it is represented on the painting). During the transfer test session, participants had to build a matching-to-sample array using the same instances but considering the untrained domain. Performance on test was evaluated qualitatively (reconstructing real time performance of participants) and quantitatively (estimating the number of arrays that were congruent with the new matching criterion). Participants who had to describe the matching criteria during training had a better performance on the extradimensional transfer test than those who did not explicitly describe matching criteria. Building matching-to-sample arrays using a new matching criterion seems to be a categorical adjustment task useful when studying referential substitutive behavior.

A Computational Model of Visual Anisotropy

Visual anisotropy has been demonstrated in multiple tasks where performance differs between vertical, horizontal, and oblique orientations of the stimuli. We explain some principles of visual anisotropy by anisotropic smoothing, which is based on a variation on Koenderink's approach in [1]. We tested the theory by presenting Gaussian elongated luminance profiles and measuring the perceived orientations by means of an adjustment task. Our framework is based on the smoothing of the image with elliptical Gaussian kernels and it correctly predicted an illusory orientation bias towards the vertical axis. We discuss the scope of the theory in the context of other anisotropies in perception.

Investigating the use of an adjustment task to set the preferred illuminance in a workplace environment

An experiment was carried out to examine user preferences for light level using the method of adjustment. The study sought preferred illuminances under lighting from fluorescent lamps of different correlated colour temperature. It was hypothesised that the preferred illuminance would be influenced by variables inherent in the experimental design including the available stimulus range, the anchor (initial setting before adjustment) and adaptation time before onset of adjustment action. The experiment included three different stimulus ranges (21–482 lux, 38–906 lux and 72–1307 lux) and these lead to significantly different preferred illuminances (337 lux, 523 lux and 645 lux, respectively). The experimental results confirmed that stimulus range and anchor have significant effects on the outcome of the adjustment task, confirming the importance of considering and reporting these variables when determining user preference with this method.

Toward evaluating material design interface paradigms for novice users

Material design is the process by which artists specify the reflectance properties of a surface, such as its diffuse color and specular roughness. We present a user study to evaluate the relative benefits of different material design interfaces, focusing on novice users since they stand to gain the most from intuitive interfaces. Specifically, we investigate the editing of the parameters of analytic bidirectional distribution functions (BRDFs) using three interface paradigms: physical sliders by which users set the parameters of analytic BRDF models, such as diffuse albedo and specular roughness; perceptual sliders by which users set perceptually-inspired parameters, such as diffuse luminance and gloss contrast; and image navigation by which material variations are displayed in arrays of image thumbnails and users make edits by selecting them. We investigate two design tasks: precise adjustment and artistic exploration. We collect objective and subjective data, finding that subjects can perform equally well with physical and perceptual sliders as long as the interface responds interactively. Image navigation performs worse than the other interfaces on precise adjustment tasks, but excels at aiding in artistic exploration. We find that given enough time, novices can perform relatively complex material editing tasks with little training, and most novices work similarly to one another.

Innovative psycho-educational program to prevent common postpartum mental disorders in primiparous women: a before and after controlled study.

BackgroundUniversal interventions to prevent postnatal mental disorders in women have had limited success, perhaps because they were insufficiently theorised, not gender-informed and overlooked relevant risk factors. This study aimed to determine whether an innovative brief psycho-educational program for mothers, fathers and first newborns, which addressed salient learning needs about infant behaviour management and adjustment tasks in the intimate partner relationship, prevented postpartum mental health problems in primiparous women.MethodsA before and after controlled study was conducted in primary care in seven local government areas in Victoria, Australia. English-speaking couples with one-week old infants were invited consecutively to participate by the maternal and child health nurse at the universal first home visit. Two groups were recruited and followed sequentially: both completed telephone interviews at four weeks and six months postpartum and received standard health care. Intervention group participants were also invited to attend a half-day program with up to five couples and one month old infants, facilitated by trained, supervised nurses. The main outcome was any Composite International Diagnostic Interview (CIDI) diagnosis of Depression or Anxiety or Adjustment Disorder with Depressed Mood, Anxiety, or Mixed Anxiety and Depressed Mood in the first six months postpartum. Factors associated with the outcome were established by logistic regression controlling for potential confounders and analysis was by intention to treat.ResultsIn total 399/646 (62%) women were recruited; 210 received only standard care and 189 were also offered the intervention; 364 (91%) were retained at follow up six months postpartum. In women without a psychiatric history (232/364; 64%), 36/125 (29%) were diagnosed with Depression or Anxiety or Adjustment Disorder with Depressed Mood, Anxiety, or Mixed Anxiety and Depressed Mood in the control group, compared with 16/107 (15%) in the intervention group. In those without a psychiatric history, the adjusted odds ratio for diagnosis of a common postpartum mental disorder was 0.43 (95% CI 0.21, 0.89) in the intervention group compared to the control group.ConclusionsA universal, brief psycho-educational group program for English-speaking first time parents and babies in primary care reduces de novo postpartum mental disorders in women. A universal approach supplemented by an additional program may improve effectiveness for women with a psychiatric history.Trial registrationACTRN 12605000567628.

Rate and duration memory of naturalistic sounds

Research has shown that the tempi of familiar songs are remarkably well-remembered with a high degree of accuracy. The goal of the present research was to determine whether this ability generalizes to various types of ecological sounds and, if so, how rate information is encoded into the cognitive system. Across three experiments, participants were familiarized with a set of sounds and later asked to remember the rate of each. Experiment 1 revealed that the inherent rate of sounds is incidentally learned such that subsequent recognition is comparable across both prospective and retrospective paradigms. Experiment 2 confirmed these findings through an adjustment task and further demonstrated that memory for event rate remains highly accurate regardless if attending is initially directed toward a sound's rate and/or pitch qualities. Lastly, Experiment 3 assessed the ability to recognize event rate vs. duration when the two dimensions systematically co-vary with one another and revealed that rate variations influence duration recognition but not vice versa. These overall findings are discussed relative to a framework that emphasizes the role of event structure in time judgment behavior.

Application of a Genetic Algorithm on the Assessment of the Capabilities of Cctuator Systems for Laser Mircro Adjustment

Laser forming with actuator systems is a very attractive process to meet the rising demand for accuracy in micro system technology. However, the actuator systems have to be designed specifically for the given adjustment task. A computer assisted design system for actuator systems for laser based micro adjustment has been developed which supports the designer by creating a number of optimized design choices from a starting design. A multiobjective genetic algorithm has been successfully applied to this task. The algorithm for evaluation of adjustment capability of the actuator system uses another single objective genetic algorithm to determine the forming capability of the actuator system. The approach is similar to the inverse kinematics algorithm used in robotics but also considers elastic forming. The irradiated components of the actuator system are treated as robotic links for which the amount of laser based forming are the link parameter. An elastic structural mechanic simulation of the actuator system with beam elements calculates the resulting adjustment movement of the actuator system. The research performed to develop a configuration of this algorithm specifically to the needs of actuator system design evaluation is presented in this paper.

Normative representation of objects and scenes: Evidence from predictable biases in visual perception and memory

Objects and scenes can be viewed at almost any distance, and so can subtend any visual angle. However, we propose that for a given visual stimulus there exists an input size that maximizes visual information needed for a given task. We term this size the “norm”, and present initial evidence suggesting that (1) perception is implicitly sensitive to the norm, and (2) memory for visual information is biased toward this norm. First, observers were presented with a picture of an isolated object (experiment 1a) or a scene (experiment 1b) and were told to adjust the visual angle of the object or the viewing distance of the scene until the image was at the “right place” to see the object or scene. Despite the subjectivity of the task, the selected size for each stimulus was remarkably consistent across observers. Second, the norms from experiment 1 were used in a boundary adjustment task. In the classical boundary extension paradigm, subjects tend to remember pictures of scenes as farther away than they were originally viewed. However, if memory is biased toward a norm point, then a view of an object should show both boundary extension and boundary compression, depending on where it is relative to the norm. Observers were presented with pictures of objects (experiment 2a) or scenes (experiment 2b) taken from different distances and displayed for 5 seconds each. Afterwards, participants adjusted the size of the object or scene so as to match the size viewed at learning. The remembered objects and scenes showed a systematic bias towards the normative size. Finally, using a change detection paradigm, we show that a change towards the norm is harder to detect then a change away from the norm, providing converging evidence that memory is biased toward a perceptual norm.

Development of a Soft-Computer Numerical Control System for Micro-Electrochemical Machining

Problem statement: In this study a kind of soft Computer Numerical Control (soft-CNC) system for micro Electrochemical Machining (micro-ECM) based on RT-Linux platform is developed. Approach: Dual-kernel structure of System is adopted: Linux and RT-Linux are used to realize timesharing tasks and real-time tasks separately. Results: The CNC Graphical User Interface (GUI) is designed by Qt and runs on Linux core space. Based on the hard real-time facilities provided by RT-Linux, the real-time tasks, including the gap detection task, gap adjustment task, interpolating task and other real-time control tasks are implemented. The Shared Memory (SHM) and RT-FIFO were adopted to construct the communication between the GUI and real-time tasks. Conclusion: A few experiments of various micro structures micro electrochemical milling on stainless steel are introduced to validate the performance of the system. The process and the results implied that the soft-CNC System is Real-time, stable and reasonable.

Stimulus range bias explains the outcome of preferred-illuminance adjustments

Review of previous studies suggests that mean preferred illuminances determined using an adjustment task tend to lie in the middle of the range of illuminances available, a stimulus range bias. This hypothesis was validated through the results of an experimental study. It is therefore suggested that the adjustment task is not an appropriate method for determining optimum illuminances.

Real time production improvement through bottleneck control

Variability is a key characteristic for evaluating the performance of a process. Small variability for a bottleneck machine can generate high production variability. Short-term production analysis and bottleneck identification are imperative for enabling optimal response to dynamic changes within the system. In comparison to the rich and abundant literature available on long-term analysis, only a small section of the literature addresses the dynamic bottleneck control policies, which may be used to maximise sustainable benefits. In this paper, a real time bottleneck control method is introduced to efficiently utilise the finite manufacturing resources and to mitigate the short-term production constraints by using two practical approaches: initial buffer adjustment and maintenance task prioritisation. The objective for real time bottleneck control is to obtain a continuous production improvement towards a balanced-line status to increase the throughput efficiently. The benefits of this method are presented by considering an industrial case study of an automotive assembly line. The results obtained from this case study show significant production improvements as compared to traditional approaches.