Edison: Database-Supported Synchronization for PDAs

One of the most important features provided by personal digital assistants is the ability to synchronize device data with data on a user's PC. Unfortunately, current synchronization protocols have significant shortcomings that limit the availability, usability, and performance of synchronization. We present Edison, a service that leverages existing off-the-shelf ORDBMS technology to address these problems. Edison allows large numbers of users to synchronize handheld devices from any point on the internet with subsets of large, shared data sets. Edison supports this functionality while transferring the minimal amount of data to and from the device. We describe the implementation of the Edison data server and protocol, and show that Edison requires minimal overhead in terms of DBMS storage and additional time per synchronization.     

Trajectory generation for open-contoured structures in robotic fibre placement

Composites have become common engineering materials in industries where the strength to weight performance of structures is a key design consideration. The major limiting factors are the high-manufacturing costs and low-production rates. Robotic fibre placement (RFP) is one alternative process to overcome the limiting factors and it is generally suitable for open-continuous components. A novel path planning algorithm for open-contoured structures, entitled the surface curve algorithm for robotic fibre placement (SCAR) is proposed. The algorithm aims to produce a uniform lay-up of composite lamina, without gap and overlap between subsequent tows. A numerical investigation into the characteristics of the algorithm is performed and presented. The algorithm is implemented on complex contoured surface and some of the results are presented in this paper.     

Effects of temperature and pressure gradients on catalyst pellet effectiveness factors—I

The dusty gas model is used to establish the effects of temperature and pressure gradients on catalyst pellet effectiveness factors for reaction systems in which species molecular weights and transport coefficients are indistinguishable and Σν_i = 0. For this class of reactions, the total molar flux of species i is shown to be expressible simply as N_i = ?cD ??_i in terms of the molar concentration, the Bosanguet diffusivity, and the mole fraction gradient. The effects of temperature and pressure gradients are reflected only in variations in molar concentration and diffusivity. Furthermore, the temperature-pressure relationship is shown to be given by the thermal transpiration equation for a pure gas.Typical numerical results are reported for first order reactions in spherical pellets under diffusive conditions ranging from the Knudsen through the bulk diffusion regimes.The variation in diffusion regime is shown to be controlled by an additional parameter α, the Knudsen to bulk diffusion ratio. Comparisons are made with the classical Weisz-Hicks nonisothermal pellet solutions based on N_i = ?D_eff?c_i. For highly exothermic reactions, effectiveness factors are 18% lower in the Knudsen regime and 30% higher in the bulk diffusion regime than are the Weisz—Hicks values. For highly endothermic reactions with a significant diffusion limitation, the effectiveness factors are 30% lower than the Weisz—Hicks values.The classical Damköehler relationship for pellet temperature rise is shown to apply in the Knudsen regime, with the maximum dimensionless center temperature given by (1 + β), where β is the heat of reaction parameter. This temperature is accompanied by a maximum dimensionless center pressure of (1 + β)^{$\text{1}\text{2}$}.In the bulk diffusion regime, the maximum center temperature is shown to be increased by the additional term β²/4. This additional temperature rise accounts for the 42% increased bulk diffusion effectiveness for highly exothermic reactions.     

Effects of sex guilt on interpersonal pleasuring.

Two experiments (120 undergraduate males) investigated whether conceptualization of sex guilt could be extended to an interpersonal physical pleasuring paradigm. In Exp I, low-guilt (as determined by the Mosher Forced-Choice Guilt Inventory) Ss administered more overall pleasure to a female confederate than did high-guilt Ss. In Exp II, in addition to a main effect for guilt, high-guilt Ss administered significantly lower levels of pleasure when they anticipated further interaction with the confederate than when they did not. Low-guilt Ss administered slightly more pleasure when they anticipated further interaction with the confederate. Results are not consistent with D. L. Mosher's (see PA, Vols 39:9269 and 40:4236) hypothesis that low-guilt Ss are more sensitive to situational cues than high-guilt Ss. It is suggested that the inconsistency was a function of the reinforcement value of interpersonal pleasuring. Although previous research required Ss to make responses that had little apparent reinforcement value, the nature of the pleasuring response did appear to have reinforcement value for both low- and high-guilt Ss, since they increased their levels of pleasuring over trials. A 3rd experiment (24 Ss) that failed to find a relationship between hostility-guilt and pleasuring provided strong support for the relation between sex guilt and interpersonal pleasuring. (17 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Punishment and the length of non-shock confinement during the extinction of avoidance.

Groups of 72 male Sprague-Dawley rats, trained to avoid in an alley with 3 distinct chambers, spent either 2, 15, or 30 sec. in the safe or goal chamber (GB) during extinction, with the remainder of the constant 150-sec intertrial interval (ITI) spent in the start box (SB). 1/2 the Ss of each group were punished (shocked) in the middle chamber during extinction, 1/2 were not. It was found that (1) the longer the goal confinement, the greater the resistance to extinction; regular extinction groups extinguished faster than the punished; and (3) there was no significant interaction between GB confinement and the punishment variable. During extinction in Exp. 2 there were 2 levels of goal confinement (2 vs. 30 sec.), equal time spent in SB in all groups, a constant ITI of 62 sec., and punishment vs. no punishment. 48 male Sprague-Dawley rats served as Ss. As anticipated, punishment prolonged extinction only for the 30-sec GB confinement; the other 3 groups extinguished at approximately the same rate. The concept of short-latency "relief" was invoked to explain this significant interaction. (French summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Some RF Characteristics of Bonding Systems

The measurement of bonding impedance has been typically limited to dc or to relatively low (<20 MHz) frequencies. However, the impedance characteristics of the bonding system should not be simply ignored at higher frequencies. To do so may be neglecting a serious source of electromagnetic interference. This paper presents techniques for the measurement and interpretation of bonding impedance characteristics through the VHF region. A measuring device based on the insertion loss technique is described. Calibration curves of typical models of this device show its usefulness for measurements up to 400 MHz. The application of this device to the measurement of bonding systems in field installations is also explored. From data obtained with the insertion loss device, an equivalent circuit of a typical bonding system is developed which incorporates the contributions of the equipment case as well as those contributions of the bonding straps to the overall impedance characteristics. It is shown that typical bonding systems exhibit regions of parallel resonance which are often at relatively low frequencies. Within these regions, the impedance of the bonding path is often very high. Because of this high impedance, the equipment case can act as a very effective antenna. Evidence is presented to show that the case voltages induced by a radiated field in the resonant frequency region may increase as much as 25 dB for a bonded system over a system that is not bonded.     

Cognitive psychology meets psychometric theory: On the relation between process models for decision making and latent variable models for individual differences.

This article analyzes latent variable models from a cognitive psychology perspective. We start by discussing work by Tuerlinckx and De Boeck (2005), who proved that a diffusion model for 2-choice response processes entails a 2-parameter logistic item response theory (IRT) model for individual differences in the response data. Following this line of reasoning, we discuss the appropriateness of IRT for measuring abilities and bipolar traits, such as pro versus contra attitudes. Surprisingly, if a diffusion model underlies the response processes, IRT models are appropriate for bipolar traits but not for ability tests. A reconsideration of the concept of ability that is appropriate for such situations leads to a new item response model for accuracy and speed based on the idea that ability has a natural zero point. The model implies fundamentally new ways to think about guessing, response speed, and person fit in IRT. We discuss the relation between this model and existing models as well as implications for psychology and psychometrics. (PsycINFO Database Record (c) 2011 APA, all rights reserved)