bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mastery pleasure versus mere ownership: A quasi‐experimental cross‐cultural and cross‐alphabetical test of the name letter effect
Authors: Hoorens Vera , Nuttin Jozef M. , Herman Ildikó Erdélyi , Pavakanun Ubolwanna 
Published: July 2012

AbstractFour studies test both the alternative explanation advanced by Hoorens and Todorova (1988) for Nuttin's (1984, 1985, 1987) name letter effect (NLE), and two interpretations for an unexplained finding of the former authors. Flemish, Hungarian and Thai children show an increasing rather than a decreasing NLE over primary school grades (studies 1, 2 and 4). Thai university students and school children prefer own name letters in their ‘mother’ alphabet (Thai) but also in their second (Roman) alphabet (studies 3 and 4). All these results contradict the primacy of own name writing or mastery pleasure hypothesis. Independently of the time interval between the acquisition of both alphabets, a stronger NLE is found in the subjects ‘mother’ alphabet than in their second alphabet, contradicting a mitigated mastery pleasure explanation for the stronger NLE in one's ‘mother’ alphabet (Hoorens and Todorova, 1988). All the data are consistent with Nuttin's interpretation of the NLE in terms of the affective consequences of ‘mere ownership’. Finally, the striking generality of the NLE over languages, alphabets, and cultures is again demonstrated.
Effects of cognitive conflict, socio‐cognitive conflict and imitation on children's socio‐legal thinking
Authors: Roy Archie W. N. , Howe Christine J. 
Published: July 2012

AbstractThe paper reports a study concerned with the effects of cognitive conflict, socio‐cognitive conflict and imitation on children's socio‐legal thinking. Nine‐year‐old children whose socio‐legal thinking was lower level were paired with 9‐ and 11‐year‐old children whose socio‐legal thinking was intermediate between lower and higher level for interaction in same sex dyads on legal transgression items. In total, 54 9‐year‐old children and 18 11‐year olds participated in the study. An experimental board game was used for all dyadic interactions. The four investigative phases included a pre‐test interview, dyadic interaction, one immediate and one delayed post‐test interview. The results indicated no overall superiority of subjects who could engage in socio‐cognitive conflict over subjects who were limited to cognitive conflict alone. In addition, lower and intermediate level subjects in both conflict conditions advanced over both post‐tests compared to a control group, arguing against a straightforward imitation account. Elements of subjects' discourse during conflict were correlated with post‐test advancement. Marked differences emerged between lows and intermediates for socio‐cognitive conflict consonant with the constructivist view that social interactions and cognitive stages are interdependent. A complementary pattern of positive correlations emerged between discourse and cognitive conflict subjects' advancement.
Social identity and perceived group homogeneity: Evidence for the ingroup homogeneity effect
Authors: Simon Bernd , Pettigrew Thomas F. 
Published: July 2012

AbstractOn the basis of social identity theory, we argue that the search for a positive social identity is characterized by the accentuation of perceived ingroup homogeneity relative to perceived outgroup homogeneity (the ingroup homogeneity effect). To test our specific hypotheses, we conducted an experiment in which some subjects were provided with a well‐defined group membership and others were allocated to ill‐defined groups. We also manipulated the information about the relative sizes of the groups. Subsequently, several measures of perceived dimensional and general group homogeneity were administered. As predicted, members of well‐defined groups revealed the ingroup homogeneity effect for an attribute associated with the definition of their group. On the other hand, members of ill‐defined groups displayed social creativity and selected alternative attributes to accentuate the relative ingroup homogeneity. Moreover, when intergroup comparisons did not contribute positively to the self‐concept, subjects accentuated their positive personal identity and evinced the outgroup homogeneity effect. Consistent with previous research, subjects identified more strongly with a well‐defined group when it was a minority rather than a majority. Minority members also perceived more general homogeneity within the ingroup than within the outgroup, whereas the majority members showed the opposite effect. Finally, the interrelationship between personal and social identity is briefly discussed.
The ‘ultimate attribution error’? A review of the literature on intergroup causal attribution
Authors: Hewstone Miles 
Published: July 2012

AbstractStudies that examine causal attributions for acts by ingroup and outgroup members are reviewed. The tendency for attributions to favour ingroup over outgroup members is found in three paradigms — explanations for positive and negative outcomes, success and failure, and group differences — and in most of the 19 studies reviewed, but the evidence provides only limited support for Pettigrew's (1979) ‘ultimate attribution error’. The evidence is limited to specific dimensions in a given study, but strongest for three general findings: (1) More internal attribution for positive acts, and less internal attribution for negative acts, by ingroup than outgroup members; (2) More attribution of outgroup than ingroup failure to lack of ability, and ‘explaining away’ outgroup success to good luck, high effort or an easy task; (3) A preference for ingroup‐serving versus outgroup‐serving attributions for group differences. Finally, theoretical issues and methodological shortcomings are discussed with reference to future research.
The effects of type of encoding and strength of discounting appeal on the success of ignoring an invalid testimony
Authors: Schul Yaacov , Manzury Frieda 
Published: July 2012

AbstractIndividuals appear to be more successful in discounting invalid evidence in studies which are set in courtroom settings than in studies done in the belief perseverance paradigm. Several differences between the two paradigms may explain this pattern. Most of these differences are ruled out by past research. We focused on differences in two domains, namely, encoding of the information and strength of the discounting appeals, and manipulated them experimentally. Even though the two manipulations were effective in influencing other judgments, they had no effect on success of discounting with guilt judgments. As in previous studies done within the courtroom paradigm, subjects were successful in discounting invalid evidence. Our interpretation for these findings involves the active process of discounting. Specifically, we assume that court settings activate a schema that leads people to deliberately correct for potential biases on the relevant guilt judgments. Since other judgments are less central within the court schema, they are not monitored actively and consequently are more susceptible to the effects of an invalid testimony.
Effect of social‐class belonging on the cognitive dissonance resulting from threat severity
Authors: Clémence Alain 
Published: July 2012

AbstractResults of two experiments using a ‘forbidden toy’ paradigm partially confirm those of a former study which showed an interaction between social‐class level of the children and threat severity on the final rankings of the toy. Lower‐class children derogated the forbidden toy more than middle‐class children in the harsh threat condition. Opposed results were observed in the mild threat condition. Interpretation of such results seems difficult in terms of cognitive dissonance theory.
Strategies for magnetizing speed‐sensorless induction machines
Authors: Hoffmann F. , Koch S. , Weidauer M. 
Published: July 2012

AbstractWhenever possible, only easily measurable quantities like stator currents and DC link voltage are used to control inverter‐fed induction motors nowadays. Also for high‐performance AC drives speed‐sensorless control of induction motors has received increasing attention from the viewpoint of cost, trouble immunity and reliability. Different algorithms for speed identification are known. They allow good performance of torque or speed control in almost the whole operating area of an induction machine without using rotational transducers. One remaining problem is to start the machine when mechanical speed is not known. This paper now presents two new strategies for magnetizing a demagnetized speed‐sensorless induction machine also with non‐zero speed.
Detection of the rotor position of a permanent‐magnet synchronous motor at standstill
Authors: Stiebler M. , Li Y. 
Published: July 2012

AbstractThis paper introduces a method to detect the rotor position of a three‐phase permanent‐magnet synchronous motor (PMSM) at standstill. It applies a test voltage pulse between two terminals of the PMSM and measures the voltage response between the free and one of the two connected terminals, from which the initial rotor position is obtained. Being based on the measured voltage response, other than using a current response, this method is less affected by temperature and saturation. In addition, this method does not require the absolute values of Ld and Lq, but only the saliency factor, which can be determined by the maximum and minimum values of the voltage response in a period of 2π of the electrical rotor angle. Some experimental results are presented to verify the applicability of the method.
VSI‐based series compensation scheme for transmission lines
Authors: Kasztenny B. , Hatziadoniu C. , Funk A. 
Published: July 2012

AbstractThis paper addresses the loadability of long transmission lines. An advanced series compensation scheme is presented consisting of a series‐connected voltage‐sourced inverter and fixed series‐capacitors. This scheme provides substantial increase of the line loadability beyond that achievable with fixed capacitive compensation alone. In addition, it provides smooth power‐flow control. Results from simulation studies demonstrate its effectiveness in improving the loadability of long transmission lines and providing damping of interarea oscillations.
Advanced concepts of analysing static VAr compensators to damp inter‐area oscillation modes
Authors: Nayebzadeh M. , Messina A. R. 
Published: July 2012

AbstractThe analysis of low‐frequency inter‐area oscillations is of special concern in large weakly interconnected power systems. The ability of static VAr compensators (SVC) to contribute to damping depends strongly on the relative location of generation, load and the SVC. A comprehensive investigation of the use of static VAr compensators to aid damping of low‐frequency inter‐area oscillations in a real weakly interconnected large power system is presented. Based on modal analysis, efficient algorithms to compute voltage‐ and power‐oscillation flow for each mode of concern are developed. Controllability and observability measures are also used to assess the impact of dynamic voltage support on system damping as well as to identify optimal locations for SVC. The knowledge gained by these techniques allows to investigate the influence of existent SVC on overall system damping as well as to evaluate suitable alternatives to site new devices. Detailed time‐domain simulations are finally performed to check the validity of the knowledge gained and to assess the impact of dynamic voltage support on system transient behaviour.
New structural approach for distribution system reliability assessment
Authors: Özdemir A. , Mekiç F. , Çaǧlar R. 
Published: July 2012

AbstractA new method is presented for distribution system reliability assessment. The method brings two distinct features. The first one is related to minimal path determination and is mainly derived from an existing method by slight modifications. The second one is related to simulation of active failures and provides a considerable time saving. The principle depends on the S and SS groups, established for the nodes existing in basic minimal cut sets. The proposed method is applied to a sample distribution network and the reported numerical values are attained with less effort.
New method for the determination of steady‐state signal characteristic values
Authors: Popescu I. , Zaharia I. , Petrescu C. 
Published: July 2012

AbstractA new method for the determination of periodic and quasi‐periodic signal characteristic values is proposed. The method consists in determining the area bounded by the closed curves obtained in the real plane where one axis is the signal and the other one is the signal integral, or the signal derivative or the k‐th harmonic of the signal (for periodic signals). In this way the signal RMS value, mean value and maximum value, the harmonic frequencies and the distortion RMS values (for periodic signals) as well as the carrier RMS value and the modulation factor (for quasi‐periodic signals) may be determined.
Genetic algorithm‐based self‐learning fuzzy PI controller for buck converter
Authors: Liao T.‐L. , Huang N.‐S. 
Published: July 2012

AbstractThis paper presents a self‐learning fuzzy proportional‐integral (PI) controller design for a buck converter. Although a triangle type of membership functions is used, their parameters for fuzzy subsets are deemed unnecessary in the fuzzy control rules design. Knowledge of both the normalization factor in the fuzzification phase and feedback gain of the PI controller is also not required. In addition, a genetic algorithm (GA) optimization technique is proposed to tune the parameters of normalization factors, membership functions and the gain of PI‐like controller. The proposed GA‐based fuzzy controller is then applied to a buck converter. Simulation results indicate that the output voltage of the closed‐loop system can be regulated to a desired reference voltage regardless of the variations in input voltage and of changes in output load.
Quasi‐periodic route to chaos and its control in a power‐system model
Authors: Srivastava K. N. , Srivastava S. C. 
Published: July 2012

AbstractBifurcation and chaos arise in a power‐system network due to its complex non‐linear dynamics. This paper first demonstrates, through numerical simulation, the existence of various types of global bifurcation in a sample 19‐bus (reduced) Indian power system. Presence of torus and quasi‐periodic route to chaos have been observed for the first time in a power‐system model. Studies have been performed to damp out the Hopf bifurcation (HB) using flexible AC transmission system (FACTS) devices such as controllable series capacitors (CSC), controllable phase angle regulator (PAR) and static VAR compensator (SVC). The appropriate selection of input to these devices has been made based on the participation of state variables in the critical mode.
Power system steady‐state estimation M‐robust approach with measurement applications
Authors: Škokljev I. , Kovačević B. , Terzija V. 
Published: July 2012

AbstractThis paper considers an approach to the estimation of the amplitude of a stochastic signal, based on the maximum‐likelihood estimation, named M‐estimation. The proposed approach is further used to build a new bad data suppression‐type algorithm for estimating parameters or states in the linear regression static model of a system. The feasibility of the approach is demonstrated with both simulated and experimental data concerning the application in power measurements and power system steady‐state estimation.
Maximum power transfer and efficiency in non‐sinusoidal conditions
Authors: Castilla M. , Montaño J. C. , Cano R. , Moreno N. 
Published: July 2012

AbstractIn this paper the effects of harmonic distortion of the supply voltage and the power transmission efficiency η on the maximum power transferred to a linear load are examined. In order to quantify these effects, a power harmonic function ψ defined. It allows calculating the characteristics of the load and the maximum power transfer (where λ is a parameter that relates the efficiency with the power transfer). The power function, power losses and the power transfer are expressed in function of both λ and the total harmonic distortion of the supply voltage (UTHD) for the maximum power‐transfer conditions. Thus, the load is synthesized by a resistor in series with a set of L‐C branches, which permits to generalize the well‐known maximum power‐transfer theorem. Numerical simulation and example results are presented.
Magnetic relief of the yoke of AC electrical machines by the iron frame
Authors: Simitsis L. , Xypteras J. 
Published: July 2012

AbstractIn the bibliography of electrical machines, the influence of the iron frame on the calculation of their magnetic circuit is assumed negligible. This paper proves that in cases of high saturation at the stator yoke of an electrical machine, the cylindrical ferromagnetic frame, which is shrunk on the stator core, has a non‐negligible influence on its magnetic circuit and particularly on the stator yoke. The existence of the frame results in the magnetic relief of the machine. The magnetic field calculations by means of the Finite‐Element Method using different B‐H curves in the cores and in the cast‐iron frame, are effected for different values of the stator yoke height.
Analysis and evaluation of zero‐voltage‐transition converters applied to DC motor drives
Authors: Chen Y.‐T. , Chou J.‐H. 
Published: July 2012

AbstractZero‐voltage‐transition (ZVT) converters which combine pulse‐width modulation (PWM) with the soft‐switching characteristics have very low voltage and current stress and the soft switching of the rectifier diode. Therefore, ZVT‐PWM converters can increase the switching frequency and consequently reduce the ripple current. Although the ZVT‐PWM converter has the above advantages, the application of ZVT‐PWM converter to DC motor drive has not been discussed until now. This paper will analyse and discuss the characteristics of ZVT‐PWM technique applied to the separately‐excited and series DC motor drives. Effects of switching frequency and duty cycle on efficiency, speed characteristic and ripple current for the various DC motors are also investigated. The comparison of the ZVT‐PWM converter‐fed DC motor with the traditional hard‐switching PWM topology shows that the ZVT‐PWM converter‐fed DC motor can reduce switching loss and ripple current and improve the efficiency even if the load variation is very large. Furthermore, the performance improvement after the addition of an adequate filter is also appreciated in this paper.
Genetic algorithm solution to economic dispatch problems
Authors: Lei X. , Lerch E. , Povh D. 
Published: July 2012

AbstractThis paper presents an economic dispatch algorithm based on the genetic algorithm (GA) for the determination of the global or quasi‐global optimum dispatch solution under consideration of transmission losses. In practice, the efficiency of GA is sometimes hindered by a poor performance in a localized search or by the difficulty of finding and maintaining feasibility for a constrained problem. To deal with these problems, an advanced genetic algorithm is developed. With the help of a local improvement operator, combined with a conjugate gradient method, the performance of the GA is enhanced. By means of heuristic scaling of fitness functions and adaptation of penalty factors, the genetic search in the feasible region can be improved. The algorithm is implemented in the binary search space and tested with multi‐modal non‐linear functions. The application of the algorithm to a test system is also demonstrated, where transmission losses are represented by the B‐matrix loss formula.
Study about the physical processes leading to partial discharges in insulating fluids
Authors: Borsi H. 
Published: July 2012

AbstractThis paper deals with the partial‐discharge (PD) behaviour of some insulating fluids used in transformers. The PD are generated on a needle‐plate electrode configuration. At first the influence of different parameters such as needle‐tip radius and gap distance on the PD inception voltage and other relevant PD characteristics of mineral‐based transformer oil are discussed. It follows a comparison of the PD behaviour of a mineral‐based transformer oil and a synthetic fluid, used as insulating liquid in transformers. Based on the results it is shown that the initiation and the propagation of PD phenomena depends on different parameters.
On a certain disadvantageous mode of the arc between cup‐shaped contacts during high‐current interruption in vacuum
Authors: Janiszewski J. , Zalucki Z. 
Published: July 2012

AbstractThe article presents research results of discharge development and arc modes of high‐current vacuum arc between cup contacts with slots to generate a transverse magnetic field (i. e. contrate contacts). The peak value of the applied AC arc current half‐wave ranged from a few kA to 27 kA. Photographs of the arc were taken with a high‐speed framing camera at 10 000 frames/s. It was found that the arc between cup‐shaped contacts behave in a similar way in the following two cases: if the electrodes are separated shortly after the onset of the main current, and if the arc is created at a fixed contact gap. It was shown that, for both cases, there is a tendency to locate the stationary anode spot inside the cup and the arising stationary constricted arc mode, which is disadvantageous in terms of arc extinction.
Power source and its new firing method for gas metal arc welding
Authors: Thamodharan M. , Vasile D. , Labudovic M. 
Published: July 2012

AbstractThe electronically controlled power sources for steady and pulsed Gas Metal Arc Welding (GMAW) consist of either converters or transistors. For steady direct current welding with a converter power source, a single fully‐controlled three‐phase bridge converter is widely used. As for pulsed DC welding, it is done with two parallel‐connected converters: a single‐phase converter for the production of pulsed direct current with different frequencies and width, and a three‐phase converter for the generation of the background current. Both these power sources are associated with a number of disadvantages. They produce harmonics in the AC mains. And in the case of the power source for pulsed welding, a low dynamic response is noticeable apart from unsymmetrical reactions in the mains caused by the single‐phase converter. In addition to these, it is complex to operate and maintain, large in size, less efficient and is relatively expensive. This paper presents a single fully‐controlled three‐phase bridge converter with a new firing method of the thyristors that can be used for both welding methods. The distortions produced in the mains as a result can be reduced with the help of two tuned resonant line filters, if needed, although they add weight, size and cost to the power source. This new method was verified by simulation and the results are presented. Through this means, the disadvantages associated especially with pulsed DC welding can be reduced to a minimum.
Komplexer ist einfacher
Authors: Brose Ulrich 
Published: July 2012

AbstractDie sechste Welle des Artensterbens auf der Erde hat gerade erst begonnen. Doch die Forschung richtet ihren Blick schon weiter: Womit haben natürliche Ökosysteme künftig zu kämpfen? Analysen ausgedehnter Netzwerke führen zu überraschend klaren Vorhersagen.