Effects of luminance and colour contrast on the search of information on display devices

For black-and-white alphanumeric information, the speed of visual perception decreases with decreasing contrast. We investigated the effect of luminance contrast on the speed of visual search and reading when characters and background differed also with respect to colour. The luminance contrast between background and characters was varied, while colour contrast was held nearly constant. Stimuli with moderate (green/grey) or high colour contrast (green/red or yellow/blue), and three character sizes (0.17, 0.37, and 1.26 deg) were used. Eye movements were recorded during the visual search task. We found that the visual search times, number of eye fixations, and mean fixation durations increased strongly with decreasing luminance contrast despite the presence of colour contrast. The effects were largest for small characters (0.17 deg), but occurred also for medium (0.37 deg), and in some cases for large (1.26 deg) characters. Similarly, reading rates decreased with decreasing luminance contrast. Thus, moderate or even high colour contrast does not guarantee quick visual perception, if the luminance contrast between characters and background is small. This is probably due to the fact that visual acuity (the ability to see small details) is considerably lower for pure colour information than for luminance information. Therefore, in user interfaces, good visibility of alphanumeric information requires clear luminance (brightness) difference between foreground and background.     

Learning Dynamic Obstacle Avoidance for a Robot Arm Using Neuroevolution

Neural networks can be evolved to control robot manipulators in tasks like target tracking and obstacle avoidance in complex environments. Neurocontrollers are robust to noise and can be adapted to different environments and robot configurations. In this paper, neurocontrollers were evolved to position the end effector of a robot arm close to a target in three different environments: environments without obstacles, environments with stationary obstacles, and environments with moving obstacles. The evolved neurocontrollers perform qualitatively like inverse kinematic controllers in environments with no obstacles and like path-planning controllers based on Rapidly-exploring random trees in environments with obstacles. Unlike inverse kinematic controllers and path planners, the approach reliably generalizes to environments with moving obstacles, making it possible to use it in natural environments.     

SQUID magnetometers for low-frequency applications

We present a novel formulation for SQUID operation, which enables us to evaluate and compare the sensitivity and applicability of different devices. SQUID magnetometers for low-frequency applications are analyzed, taking into account the coupling circuits and electronics. We discuss nonhysteretic and hysteretic single-junction rf SQUIDs, but the main emphasis is on the dynamics, sensitivity, and coupling considerations of dc-SQUID magnetometers. A short review of current ideas on thin-film, dc-SQUID design presents the problems in coupling and the basic limits of sensitivity. The fabrication technology of tunnel-junction devices is discussed with emphasis on how it limits critical current densities, specific capacitances of junctions, minimum linewidths, conductor separations, etc. Properties of high-temperature superconductors are evaluated on the basis of recently published results on increased flux creep, low density of current carriers, and problems in fabricating reliable junctions. The optimization of electronics for different types of SQUIDs is presented. Finally, the most important low-frequency applications of SQUIDs in biomagnetism, metrology, geomagnetism, and some physics experiments demonstrate the various possibilities that state-of-the-art SQUIDs can provide.     

Memory prerequisites of mismatch negativity in the auditory event-related potential (ERP).

The mismatch negativity (MMN) is a component of the auditory event-related brain potential that occurs in response to infrequent changes in the physical properties of homogeneous series of sounds, even when Ss are instructed to ignore the auditory channel of stimulation. It has been proposed (e.g., R. N??t?nen, see record 1991-00298-001) that the MMN is generated by an automatic process in which a difference between the deviant sound and the previous, standard sound is detected by the brain. However, it is unclear how the form of memory involved is related to the rest of the memory system. The present study indicates that, for an MMN to be elicited in response to a change in tone frequency, the representation of the standard tone must be both well-established as a standard in memory and in a currently active state. The relation between physiological and psychological aspects of memory representation is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Bonded thick film SOI with pre-etched cavities

We have studied direct bonding and thinning of pre-etched silicon wafers. Silicon-on-insulator (SOI) substrates with pre-etched cavities provide freedom to MEMS design and enable manufacturing of advanced sensor structures (sensor structures that would be difficult or impossible with conventional substrates). Cavities with different shapes and sizes were etched on to the handle wafers. The etched handle wafers were bonded to unpatterned cap wafers in air or in vacuum. The bonding quality was evaluated with scanning acoustic microscopy and with HF-etching test. After bonding, the cap wafers were thinned down with grinding and polishing. The thickness variation of silicon diaphragm over the cavities was evaluated with cross-sectional SEM. The deflection of the Si film was measured with surface profilometry. To decrease the deflection and the thickness variation of the film, different support structures were placed inside the cavities.The bonding experiments carried out with patterned wafers showed that vacuum bonding results in slightly higher bonding energy than bonding in air. With large cavity fraction (80% of total wafer area), the air bonded samples had large void on the bonded interface. With smaller cavity fractions or with vacuum bonded samples, no such voids were found. Thinning studies showed that the thickness variation of the silicon diaphragm increases with increasing cavity dimensions and with decreasing SOI layer thickness. Thickness variation can be reduced with support structures under the Si membrane.     

Flaxseed in Breadmaking: Effects on Sensory Quality, Aging, and Composition of Bakery Products

ABSTRACT:  This paper describes the effect of flaxseed on two bread formulations. The quality of bread rolls—containing flaxseed—and the quality of cinnamon rolls—containing flaxseed and flaxseed oil—is determined by sensory evaluation (texture, odor, and flavor), instrumental texture measurement and chemical analysis (fatty acids, fiber, secoisolarisiresinol diglycoside, and cadmium). Bread aging is monitored by measuring sensory attributes during storage. The results indicate that the flaxseed rolls retain moisture and softness more efficiently than the control rolls that do not contain flaxseed. No off-odors were detected during the storage period from 0 to 6 d at room temperature (+22 °C), although flaxseed rolls and cinnamon rolls were discovered to be high in unsaturated fats. The major fatty acid in both bakery samples that contained flaxseed was α-linolenic acid. The flaxseed rolls were also high in fiber. Therefore, from a nutritional viewpoint flaxseed shows beneficial properties in breadmaking. It has a positive impact on the texture parameters during storage as well as on the nutritional composition, for example, the content of fiber and unsaturated fats.     

Total amitraz residues in bee honeys]

A total of 330 bee honey samples was analysed in 1986-1990, and the results are reported. Analysis was performed according to the method for the amitraz total residue determination by hydrolysis and steam distillation as described. 60% of the honeys were practically not contamined (total residue content amounting to 0.01 mg/kg), 8.5% of the honeys contained more than 0.05 mg/kg. Maximal values of 0.2-0.5 mg/kg were stated. 54% of the rape-honeys contained more than 0.01 mg/kg, 19% more than 0.05 mg/kg.     

Fatty acids of a salami-type sausage made of Baltic herring fillets, pork and lard

 The fatty acid composition of "fish wurst", a fermented salami-type sausage made of pork, lard and Baltic herring fillets (Clupea harengus var. membras) was investigated. Changes in the proportions of the 35 most abundant fatty acids were examined throughout the 1-month ripening period followed by a 4-month storage period. The fat composition of the product was stable (32–35%) and retained the characteristics of the main ingredients: oleic acid (37.4%, mean of three production batches) palmitic acid (23.7%) and linoleic acid (10.7%) from lard and fish, stearic acid (11.7%) mainly from lard, and palmitoleic acid (3.0%) and long-chain (C20–C24), polyunsaturated fatty acids (c.a. 6%) mainly from fish. During the 4-week ripening period a statistically significant increase (P≤0.05) was detected in the proportions of minor fatty acids only, i.e. eicosenoic acid (20 : 1n-9), eicosadienoic acid (20 : 2n-6), docosadienoic acid (22 : 2n-6) and docosatrienoic acid (22 : 3n-3). During the 4-month storage of the ripe sausage, the fatty acid composition stabilized. Only the proportion of stearic acid increased significantly during storage, from 11.7% to 12.5%. Received: 23 January 1998 / Revised version: 1 April 1998     

Die bestimmung des Schwefels im Sprit nach der Verbrennungsmethode

Zusammenfassung Die Lampen-Methode von American Society of Testing Materials (A. S. T. M.) zur Bestimmung des Schwefelgehaltes in Erdölprodukten wurde für die Bestimmung von kleinen im Sprit als Verunreinigung vorkommenden Schwefelmengen modifiziert. Für die Bestimmung wurde eine Apparatur entworfen und ausgeführt, in der der Sprit in einem entschwefelten Luftstrom verbrannt und der schwefelenthaltende Teil der Verbrennungsgase quantitativ absorbiert wird. Der Aufbau und die Anwendung der Apparatur werden eingehend beschrieben. Mit der Apparatur können gleichzeitig drei Doppelbestimmungen durchgeführt werden.Der zu Schwefeldioxyd oxydierte Schwefel wird in ammoniakalischer Wasserstoffperoxydlösung absorbiert und der gebildete Sulfatschwefel in einer alkoholhaltigen Lösung als Benzidinsulfat gefällt. Die Benzidin- (Schwefel-) Menge wird spektrophotometrisch bei der Wellenlänge 250 mµ (2500 Å) bestimmt.Der totale Erfassungsbereich der Methode bei Verbrennung von etwa 20 g Sprit beträgt 0,015–6,0 mg Schwefel in 100 ml Sprit. Nach den durchgeführten Probebestimmungen bei Schwefelgehalten von 2,1 und 0,77 mg in 100 ml war die Streuung etwa 0,09 und der mittlere Fehler etwa 0,04. Bei den Schwefelgehalten unter 0,2 mg in 100 ml müssen die Resultate als halbquantitativ behandelt werden. Durch Vergrößerung der verbrannten Spritmenge ist es möglich, die Methode empfindlicher zu machen.Die Methode ist auch für die Bestimmung des Schwefelgehaltes in Methanol und anderen Alkoholen geeignet.